AEH20A24P - Emerson Network Power - Embedded Power

-1-

A

AE

EH

H

Ha

al

lf

f-

-b

br

ri

ic

ck

k

2

24

4V

V

I

In

np

pu

ut

t

S

Se

er

ri

ie

es

s

T

Te

ec

ch

hn

ni

ic

ca

al

l

R

Re

ef

fe

er

re

en

nc

ce

e

N

No

ot

te

es

s

24V Input, 2.5V

24V Input, 2.5V, 3.3V

, 3.3V, 5V Output

, 5V Output

50-150 W

50-150 Watt DC-DC Converter

att DC-DC Converter

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-2-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Introduction

The AEH 24Vin series comes in a industry stan-

dard half-brick package of 2.4" x 2.28" x 0.5"

and footprint, and incorporates the super high

efficiency up to 87% in 2.5V output and high

power density up to 54.8W/in3. The AEH 24Vin

series is available with 2:1 input range of 18-

36V. Outputs of 2.5V, 3.3V, and 5V are fully iso-

lated from input and the isolation voltage is

1500Vdc. The typical efficiencies are 88% for

the 5V output, 87% for the 3V output, and

86% for the 2.5V output.

Designed using a synchronous rectification

topology, AEH 24Vin series incorporates simple

structure, good electrical performance and high

reliability. Standard features include input LVP,

OCP, output OVP, short circuit protection, and

over-temperature protection. Using aluminum

based plate, the maximum case temperature

can reach 100 °C without derating.

The AEH 24Vin series is designed to meet

CISPR22, FCC Class A, UL, TUV, and CSA

certifications.

Design Features

! High Efficiency

! High power density

! Low output noise

! Metal baseplate

! CNT function

! Remote sense

! Trim function

! Input under-voltage lockout

! Output short circuit protection

! Output current limiting

! Output over-voltage protection

! Overtemperature protection

! High input-output isolation voltage

Options

! Heat sink available for extended operation

! Choice of remote on/off logic configuration

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-3-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Fuse*

Trim

-Vo

-Sense

+Vo

+Sense

-Vin

CNT

+Vin

Load

C4 C2*

CASE

Vin

C1*



C3

Fuse*: Use external fuse ( fast blow type ) for each unit.

50W output : 10A fuse

75W output : 15A fuse

100W output : 20A fuse

150W output : 40A fuse

C1*: Recommended input capacitor C1

-20 oC ~ +100 oC : m 100uF/63V electrolytic or ceramic type capacitor.

-40 oC ~ +100 oC : m 100uF/63V ceramic type capacitor only.

C2*: Recommended output capacitor C2

-20 oC ~ +100 oC : 2200uF/10V (electrolytic capacitor)

-40 oC ~ +100 oC : For this temperature range, use two pieces of the recommended capacitor

above.

C3: Recommended 4700pF/2000V

C4: Recommended 1µF/10V

T

Typical Application

ypical Application

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-4-

Block Diagram

Ordering Information

AEH10G24 18-36V 2.5V 10A 40 150 84% 86%

AEH10F24 18-36V 3.3V 10A 40 150 85% 87%

AEH10A24 18-36V 5V 10A 40 150 86% 88%

*AEH15G24 18-36V 2.5V 15A 40 150 84% 86%

*AEH15F24 18-36V 3.3V 15A 40 150 85% 87%

*AEH15A24 18-36V 5V 15A 40 150 86% 88%

AEH20G24 18-36V 2.5V 20A 40 150 84% 86%

AEH20F24 18-36V 3.3V 20A 40 150 85% 87%

AEH20A24 18-36V 5V 20A 40 150 86% 88%

*AEH30G24 18-36V 2.5V 30A 40 150 84% 86%

*AEH30F24 18-36V 3.3V 30A 40 150 84% 86%

*AEH30A24 18-36V 5V 30A 40 150 86% 88%

*: detailed information refering to the factory

Model Input Output Output Ripple Noise Efficiency

Number Voltage Voltage Current (mV rms) (mV pp) min typ

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-5-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Absolute Maximum Rating

Input Voltage(continuous) -0.3 40 Vdc

Input Voltage(peak/surge) -0.3 50 Vdc 100ms non-repetitive

Case temperature -40 100 °C

storage temperature -55 125 °C

Input Characteristics

Input Voltage Range 18 24 36 Vdc

Input Reflected Current 25 80 mAp-p

T urn-of f Input Voltage 14 15.5 17 V

T urn-on Input Voltage 15 16.5 18 V

T urn On Time 15 25 ms

Control Function

Logic High 3 15 Vdc Reverse logic option “P” available

Logic Low 1.2 Vdc

Control Current 2 mA

General Specifications

MTBF 1,880 k Hrs Bellcore TR332, Tc=30°C

Isolation 1500 Vdc

Pin solder temperature 260 °C wave solder < 10 s

Hand Soldering Time 5 s iron temperature 425°C

Weight 70 grams

Characteristic Min Typ Max Units Notes

AEH10G24 Output Characteristics

Power 25 W

Output Current 10 A

Output Setpoint Voltage 2.45 2.5 2.55 Vdc Vin=24V, Io=10A

Line Regulation 0.02 0.2 %Vo Vin=18~36V, Io=10A

Load Regulation 0.1 0.5 %Vo Io=0~10A, Vin=24V

Dynamic Response

50-75% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 11 12.5 14 A

Short Circuit Current 17 A

Efficiency 84 86 % Vin=24V, Io=10A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 3 3.9 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (p-p) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 180 kHz

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-6-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Characteristic Min Typ Max Units Notes

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-7-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AEH10F24 Output Characteristics

Power 33 W

Output Current 10 A

Output Setpoint Voltage 3.25 3.3 3.35 Vdc Vin=24V, Io=10A

Line Regulation 0.02 0.2 %Vo Vin=18~36V, Io=10A

Load Regulation 0.1 0.5 %Vo Io=0~10A, Vin=24V

Dynamic Response

50-75% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 11 12.5 14 A

Short Circuit Current 17 A

Efficiency 85 87 % Vin=24V, Io=10A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 3.9 5.0 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (p-p) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 270 kHz

Characteristic Min Typ Max Units Notes

AEH10A24 Output Characteristics

Power 50 W

Output Current 10 A

Output Setpoint Voltage 4.92 5.0 5.08 Vdc Vin=24V, Io=10A

Line Regulation 0.02 0.2 %V o Vin=18~36V, Io=10A

Load Regulation 0.1 0.5 %V o Io=0~10A, V in=24V

Dynamic Response

50-75% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 11 12 14 A

Short Circuit Current 17 A

Efficiency 86 87 % Vin=24V, Io=10A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 5.75 7 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (pp) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 330 kHz

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-8-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Characteristic Min Typ Max Units Notes

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-9-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AEH20G24 Output Characteristics

Power 50 W

Output Current 20 A

Output Setpoint Voltage 2.45 2.5 2.55 Vdc Vin=24V, Io=20A

Line Regulation 0.02 0.2 %V o Vin=18~36V, Io=20A

Load Regulation 0.1 0.5 %V o Io=0~20A, V in=24V

Dynamic Response

50-75% load 1.5 %V o Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1.5 %V o Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 22 25 28 A

Short Circuit Current 30 A

Efficiency 84 86 % Vin=24V, Io=20A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 3 3.9 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (pp) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 180 kHz

Characteristic Min Typ Max Units Notes

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-10-

AEH20F24 Output Characteristics

Power 66 W

Output Current 20 A

Output Setpoint Voltage 3.25 3.3 3.35 Vdc Vin=24V, Io=20A

Line Regulation 0.02 0.2 %V o Vin=18~36V, Io=20A

Load Regulation 0.1 0.5 %V o Io=0~20A, V in=24V

Dynamic Response

50-75% load 1.5 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1.5 %Vo Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 22 25 28 A

Short Circuit Current 30 A

Efficiency 86 87 % Vin=24V, Io=20A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 3.9 5.0 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (pp) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 330 kHz

Characteristic Min Typ Max Units Notes

AEH20A24 Output Characteristics

Power 100 W

Output Current 20 A

Output Setpoint Voltage 4.92 5.0 5.08 Vdc Vin=24V, Io=20A

Line Regulation 0.02 0.2 %Vo Vin=18~36V, Io=20A

Load Regulation 0.1 0.5 %V o Io=0~20A, V in=24V

Dynamic Response

50-75% load 1.5 %V o Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

50-25% load 1.5 %V o Ta=25°C, DI/Dt=1A/10µs

100 µs Ta=25°C, DI/Dt=1A/10µs

Current Limit Threshold 22 24.5 28 A

Short Circuit Current 30 A

Efficiency 86 88 % Vin=24V, Io=20A

T rim Range 90 110 %Vo

Over Voltage Protection Setpoint 5.75 7.0 V

Sense Compensation 0.5 V 0.25V each leg

Temperature Regulation 0.02 %V o/°C

Ripple (rms) 20 mV ( 0 to 20MHz Bandwidth )

Noise (pp) 100 mV ( 0 to 20MHz Bandwidth )

Over Temperature Protection 105 °C

Switching Frequency 330 kHz

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-11-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Characteristic Min Typ Max Units Notes

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-12-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Characteristic Curves

Characteristic Curves (at 25

(at 25 °C)

°C)

Typical Efficiency AEH10G24

60

65

70

75

80

85

90

0246810

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

Typical Efficiency AEH10F24

60

65

70

75

80

85

90

0246810

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

60

65

70

75

80

85

90

0246810

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

60

65

70

75

80

85

90

048121620

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

Typical Efficiency AEH10A24 Typical Efficiency AEH20G24

60

65

70

75

80

85

90

048121620

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

60

65

70

75

80

85

90

048121620

Io

Efficiency (%)

Vin=18V

Vin=24V

Vin=36V

Typical Efficiency AEH20F24 Typical Efficiency AEH20A24

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Characteristic Curves

Characteristic Curves (at 25

(at 25 °C)

°C)

AA

AAVV

VVEE

EE

HH

HHii

iigg

gghh

hh

EE

EEff

ffff

ffii

iicc

ccii

iiee

eenn

nncc

ccyy

yy

SS

SSee

eerr

rrii

iiee

eess

ss

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

11

1188

88

VV

VVDD

DDCC

CC

tt

ttoo

oo

33

3366

66

VV

VVDD

DDCC

CC

II

IInn

nnpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-13-

Typical Output Overcurrent Characteristics

AEH10G24

0

0.6

1.2

1.8

2.4

3

03691215

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

Typical Output Overcurrent Characteristics

AEH10F24

0

0.8

1.6

2.4

3.2

4

0 3 6 9 12 15

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

0

1

2

3

4

5

6

0 3 6 9 12 15 18

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

0.6

1.2

1.8

2.4

3

0 7 14 21 28

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

Typical Output Overcurrent Characteristics

AEH10A24 Typical Output Overcurrent Characteristics

AEH20G24

0.7

1.4

2.1

2.8

3.5

0 6 12 18 24 30

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

1

2

3

4

5

6

0 5 10 15 20 25 30

Output Voltage (volts)

Output Curent (amps)

Vin=18V

Vin=24V

Vin=36V

Typical Output Overcurrent Characteristics

AEH20F24 Typical Output Overcurrent Characteristics

AEH10A24

Characteristic Curves

Characteristic Curves (at 25

(at 25 °C)

°C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-14-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Input-Output Characteristics

AEH10G24

Input Voltage (volts)

Input Current (amps)

0

0.5

1

1.5

2

010203040

Typical Input-Output Characteristics

AEH10F24

Input Voltage (volts)

Input Current (amps)

0

0.5

1

1.5

2

2.5

0 10203040

Input Voltage (volts)

Input Current (amps)

0

1

2

3

4

010203040

Input Voltage (volts)

Input Current (amps)

0

1

2

3

4

010203040

Typical Input-Output Characteristics

AEH10A24 Typical Input-Output Characteristics

AEH20G24

Input Voltage (volts)

Input Current (amps)

0

1

2

3

4

5

0 10203040

Input Voltage (volts)

Input Current (amps)

0

2

4

6

8

0 10203040

Typical Input-Output Characteristics

AEH20F24 Typical Input-Output Characteristics

AEH20A24

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-15-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

T

Transient response

ransient response (24V rated input, variable load, at 25 °C)

(24V rated input, variable load, at 25 °C)

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH10G24

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH10F24

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH10A24

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH20G24

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH20F24

Typical Transient Response to Step Load

Change from 25%-50%-25%Iomax

AEH20A24

T

Transient response

ransient response (24V rated input, variable load, at 25 °C)

(24V rated input, variable load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-16-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Transient Response to Step Load

Change from 75%-50%-75%Iomax

AEH10G24

Typical Transient Response to Step Load

Change from 75%-50%-75%Iomax

AEH10F24

Typical Transient Response to Step Load

Change from 75%-50%-75%Iomax

AEH10A24

Typical Transient Response to Step Load

Change from 50%-75%-50%Iomax

AEH20G24

Typical Transient Response to Step Load

Change from 50%-75%-50%Iomax

AEH20F24

Typical Transient Response to Step Load

Change from 75%-50%-75%Iomax

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-17-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Start-Up from Power On

AEH10G24 Typical Start-Up from Power On

AEH10F24

Typical Start-Up from Power On

AEH10A24 Typical Start-Up from Power On

AEH20G24

Typical Start-Up from Power On

AEH20F24 Typical Start-Up from Power On

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-18-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Shut-down from Power Off

AEH10G24 Typical Shut-down from Power Off

AEH10F24

Typical Shut-down from Power Off

AEH10A24 Typical Shut-down from Power Off

AEH20G24

Typical Shut-down from Power Off

AEH20F24 Typical Shut-down from Power Off

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-19-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Start-Up Transient with Remote On/Off

AEH10G24 Typical Start-Up Transient with Remote On/Off

AEH10F24

Typical Start-UpTransient with Remote On/Off

AEH10A24 Typical Start-UpTransient with Remote On/Off

AEH20G24

Typical Start-UpTransient with Remote On/Off

AEH20F24 Typical Start-UpTransient with Remote On/Off

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-20-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Shut-down Transient with

Remote On/Off

AEH10G24

Typical Shut-downTransient with

Remote On/Off

AEH10F24

Typical Shut-downTransient with

Remote On/Off

AEH10A24

Typical Shut-downTransient with

Remote On/Off

AEH20G24

Typical Shut-downTransient with

Remote On/Off

AEH20F24

Typical Shut-downTransient with

Remote On/Off

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-21-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Typical Output Ripple Voltage

AEH10G24 Typical Output Ripple Voltage

AEH10F24

Typical Output Ripple Voltage

AEH10A24 Typical Output Ripple Voltage

AEH20G24

Typical Output Ripple Voltage

AEH20F24 Typical Output Ripple Voltage

AEH20A24

Characteristic Curves

Characteristic Curves (24V rated input voltage, full load, at 25 °C)

(24V rated input voltage, full load, at 25 °C)

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-22-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Overvoltage Protection

AEH10G24 Overvoltage Protection

AEH10F24

Overvoltage Protection

AEH10A24 Overvoltage Protection

AEH20G24

Overvoltage Protection

AEH20F24 Overvoltage Protection

AEH20A24

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-23-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Pin Location

The +Vin and -Vin input connection pins are

located as shown in Figure 1. AEH 24Vin con-

verters have a 2:1 input voltage range and can

accept 18-36 Vdc.

Care should be taken to avoid applying

reverse polarity to the input which can dam-

age the converter.

Input Characteristic

Fusing:

The AEH 24Vin power modules have no

internal fuse. An external fuse must always

be employed! To meet international safety

requirements, a 250 Volt rated fuse should be

used. If one of the input lines is connected to

chassis ground, then the fuse must be placed in

the other input line.

Standard safety agency regulations require

input fusing. Recommended fuse ratings for the

AEH 24Vin Series are shown in Table 1.

Input Reverse V

Input Reverse Voltage Protection

oltage Protection

Under installation and cabling conditions where

reverse polarity across the input may occur,

reverse polarity protection is recommended.

Protection can easily be provided as shown in

Figure 2. In both cases the diode rating is deter-

mined by the power of the converter. Diodes

should be rated as shown in Table1.

Placing the diode across the inputs rather

than in-line with the input offers an advan-

tage in that the diode only conducts in a

reverse polarity condition, which increases

circuit efficiency and thermal performance.

Input Undervoltage Protection

The AEH 24Vin series is protected against

undervoltage on the input. If the input voltage

drops below the acceptable range, the convert-

er will shut down. It will automatically restart

when the undervoltage condition is removed.

-Vin

Case

CNT

+Vin +Vout



+Sense

Trim

-Sense

-Vout

5.1 (0.2)

10.16 (0.4)

15.24 (0.6)

4.8 (0.19) 48.26 (1.9)

10.16 (0.4)

7.62 (0.3)

57.9 (2.28)

61.0 (2.4)

mm (inches)

7-

12.7 (0.5)

Mounting Inserts

M3 thru hole x4



2-

φ2.0 (0.09) 



only +Vo and -Vo

φ1.0 (0.04)

all pins except +Vo and -Vo



Length optional

5.8 (0.228) default

Pin Length Option

4.80mm ! 0.5mm

0.189in. ! 0.020in.

3.80mm ! 0.25mm

0.150in. ! 0.010in.

2.80mm ! 0.25mm

0.110in. ! 0.010in.

5.8mm ! 0.5mm

0.228in. ! 0.02in.

Device Code Suffix

-4 

-6

-8

none

Top View

Fig.1. Dimensions

T

Table 1

able 1

Series Fuse Rating(24Vin)

50W 10A

75W 15A

100W 20A

150W 40A

+Vin

-Vin

+Vin

-Vin

Fig.2. Reverse Polarity Protection Circuits

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-24-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Input Filter

Input filters are included in the converters to

help achieve standard system emissions certifi-

cations. Some users however, may find that

additional input filtering is necessary. The AEH

24Vin 2.5Vout series has an internal switching

frequency of 180kHz so a high frequency

capacitor mounted close to the input terminals

produces the best results. To reduce reflected

noise, a capacitor can be added across the

input as shown in Figure 3, forming a πfilter. A

100µF/63V electrolytic capacitor is recom-

mended for C1.

For conditions where EMI is a concern, a differ-

ent input filter can be used. Figure 4 shows an

input filter designed to reduce EMI effects. L1,

L2 is a 2mH common mode choke.

When a filter inductor is connected in series

with the power converter input, an input capac-

itor C1should be added. An input capacitor C1

should also be used when the input wiring is

long, since the wiring can act as an inductor.

Failure to use an input capacitor under these

conditions can produce large input voltage

spikes and an unstable output.

Control Function

Two remote on/off options are available.

Negative logic applying a voltage less than

1.2V to the CNT pin will enable the output, and

applying a voltage greater than 3V will disable

it.

Positive logic applying a voltage larger than

3V to the CNT pin will enable the output, and

applying a voltage less than 1.2V will disable it.

Positive logic, device code suffix “ P “ .

Negative logic, device code suffix nothing is the

factory-preferred.

If the CNT pin is left open, the converter will

default to “ control off ” operation in nega-

tive logic, but default to “ control on ” in

positive logic.

The maximum voltage that can be applied to

the control pin is 15V.

+Vin

-Vin

C1

Fig.3. Ripple Rejection Input Filter

DC/DC

Vin+

Vin-Case

4700pF

+

L1

4700pF

1uF

L2

RL

2200uF

1uF1000pF

1000pF

1uF

220uF

Fig.4. EMI Reduction Input Filter

-Vin

CNT

-Vin

CNT

-Vin

CNT

-Vin

CNT

Fig.8. Relay Control

Fig.5. Simple Control

Fig.6. Transistor Control

Fig.7. Isolated Control

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-25-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Input-Output

Characteristic

Safety Consideration:

For safety-agency approval of the system in

which the power module is used, the power

module must be installed in compliance with the

spacing and separation requirements of the

end-use safety agency standard, i.e., UL1950,

CSA C22.2 No. 950-95, and EN60950.

The input-to-output 1500VDC isolation is an

operational insulation. The DC/DC power mod-

ule should be installed in end-use equipment, in

compliance with the requirements of the ulti-

mate application, and is intended to be supplied

by an isolated secondary circuit. When the sup-

ply to the DC/DC power module meets all the

requirements for SELV(<60Vdc), the output is

considered to remain within SELV limits (level

3). If connected to a non-SELV power system,

double or reinforced insulation must be provid-

ed in the power supply that isolates the input

from any hazardous voltages, including the ac

mains. One Vi pin and one Vo pin are to be

grounded or both the input and output pins are

to be kept floating. Single fault testing in the

power supply must be performed in combina-

tion with the DC/DC power module to demon-

strate that the output meets the requirement for

SELV. The input pins of the module are not

operator accessible.

Note: Do not ground either of the input pins of

the module, without grounding one of the output

pins. This may allow a non-SELV voltage to

appear between the output pin and ground.

Case Grounding:

For proper operation of the module, the case or

baseplate of the AEH 24Vin module does not

require a connection to a chassis ground. If the

AEH module is not in a metallic enclosure in a

system, it may be advisable to directly ground

the case to reduce electric field emissions.

Leaving the case floating can help to reduce

magnetic field radiation from common mode

noise currents. If the case has to be grounded

for safety or other reasons, an inductor can be

connected to chassis at DC and AC line fre-

quencies, but be left floating at switching fre-

quencies. Under this condition, the safety

requirements are met and the emissions are

minimized.

Output

Characteristic

Minimum Load Requirements:

There no minimum load required for the AEH

24Vin series modules.

Remote Sensing:

The AEH 24Vin converter can remotely sense

both lines of its output which moves the effec-

tive output voltage regulation point from the out-

put of the unit to the point of connection of the

remote sense pins. This feature automatically

adjusts the real output voltage of the AEH

24Vin in order to compensate for voltage drops

in distribution and maintain a regulated voltage

at the point of load.

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-26-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

When the converter is supporting loads far

away, or is used with undersized cabling, sig-

nificant voltage drop can occur at the load. The

best defense against such drops is to locate the

load close to the converter and to ensure ade-

quately sized cabling is used. When this is not

possible, the converter can compensate for a

drop of up to 0.5V, through use of the sense

leads.

When used, the + and - Sense leads should be

connected from the converter to the point of

load as shown in Figure 9 using twisted pair

wire. The converter will then regulate its output

voltage at the point where the leads are con-

nected. Care should be taken not to reverse the

sense leads. If reversed, the converter will trig-

ger the OVP protection and turn off. When not

used, the +Sense lead must be connected

with +Vo directly, and -Sense with -Vo. Also

note that the output voltage and the remote

sense voltage offset must be less than the min-

imum overvoltage trip point. Note that at ele-

vated output voltages the maximum power

rating of the module remains the same, and

the output current capability will decrease

correspondingly.

Output T

Output Trimming:

rimming:

Users can increase or decrease the output volt-

age set point of a module by connecting an

external resistor between the TRIM pin and

either the SENSE (+ ) or SENSE ( - ) pins. The

trim resistor should be positioned close to the

module. If not using the trim feature, leave

the TRIM pin open.

Trimming up by more than 10% of the nominal

output may damage the converter or trig the

OVP protection. Trimming down more than

10% can cause the converter to regulate

improperly. Trim down and trim up circuits and

the corresponding configuration are shown in

Figure 10 to Figure 15 next page.

Note that at elevated output voltages the

maximum power rating of the module

remains the same, and the output current

capability will decrease correspondingly.

Output Over-Current Protection:

AEH 24Vin series DC/DC converters feature

foldback current limiting as part of their

Overcurrent Protection (OCP) circuits. When

output current exceeds 110 to 140% of rated

current, such as during a short circuit condition,

the output will shutdown immediately, and can

tolerate short circuit conditions indefinitely.

When the overcurrent condition is removed, the

converter will automatically restart.

+Vout

-Vout

Load

+Sense

-Sense

Twisted Pair +S

-S

Fig.9. Sense Connections

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-27-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Radj-down=

where y is the adjusting percentage of the voltage.

Radj-down is in kohms.

0 < y < 10

V

I

(+)

V

I

(–)

ON/OFF

CASE

V

O

(+)

V

O

(–)

SENSE(+)

TRIM

SENSE(–) R

adj-down

R

LOAD

100

y- 2

% Change In Output Voltage (y)

Adjustment Resistor Value (kΩ)

0

10

20

30

40

50

60

70

80

90

100

012345678910

Fig.15. Resistor Selection for Trimming

Down Output Voltage

Fig.14. Circuit Configuration and Equation

to Trim Down Output Voltage

0

10

20

30

40

50

60

70

80

90

100

012345678910

% Change In Output Voltage (y)

Adjustment Resistor Value (kΩ)

Radj-up = (100+2y)

1.26y y

where y is the adjusting percentage of the voltage.

Radj-up is in kohms.

0 < y < 10

Vo(100+y)

V

I

(+)

V

I

(–)

ON/OFF

CASE

V

O

(+)

V

O

(–)

SENSE(+)

TRIM

SENSE(–)

R

adj-up

R

LOAD

-

Fig.11. Resistor Selection for Trimming Up

2.5V Outputs

Fig.10. Circuit Configuration and Equation

to Trim Up Output Voltage

% Change In Output Voltage y

Adjustment Resistor Value (kΩ)

0

20

40

60

80

100

120

140

160

180

200

012345678910

% Change In Output Voltage (y)

Adjustment Resistor Value (kΩ)

0

30

60

90

120

150

180

210

240

270

300

012345678910

Fig.13. Resistor Selection for Trimming Up

5V Outputs

Fig.12. Resistor Selection for Trimming Up

3.3V Outputs

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-28-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Output Filters

When the load is sensitive to ripple and noise,

an output filter can be added to minimize the

effects. A simple output filter to reduce output

ripple and noise can be made by connecting a

capacitor across the output as shown in Figure

16. The recommended value for the output

capacitor C1 is 2,200µF/10V.

Extra care should be taken when long leads or

traces are used to provide power to the load.

Long lead lengths increase the chance for

noise to appear on the lines. Under these con-

ditions C2 can be added across the load as

shown in Figure 15. The recommended compo-

nent for C2 is 2200µF/10V capacitor and con-

necting a 0.1µF ceramic capacitor C1 in paral-

lel generally.

Decoupling

Noise on the power distribution system is not

always created by the converter. High speed

analog or digital loads with dynamic power

demands can cause noise to cross the power

inductor back onto the input lines. Noise can be

reduced by decoupling the load. In most cases,

connecting a 10 µF tantalum capacitor in paral-

lel with a 0.1µF ceramic capacitor across the

load will decouple it. The capacitors should be

connected as close to the load as possible.

Ground Loops

Ground loops occur when different circuits are

given multiple paths to common or earth

ground, as shown in Figure 18. Multiple ground

points can slightly different potential and cause

current flow through the circuit from one point to

another. This can result in additional noise in all

the circuits. To eliminate the problem, circuits

should be designed with a single ground con-

nection as shown in Figure 19.

Output Over-V

Output Over-Voltage Protection:

oltage Protection:

The over-voltage protection has a separate

feedback loop which activates when the output

voltage is between 120% and 140% of the

nominal output voltage. When an over-voltage

condition occurs, a “ turn off “ signal was sent

to the input of the module, and shut off the out-

put. The module will restart after power on

again.

+Vout

-Vout

Load

C1C2

Fig.17. Output Ripple Filter For a Distant

Load

+Vout

-Vout

Load

C1

Fig.16. Output Ripple Filter

+Vout

-Vout

Load Load

RLine

RLine RLine

RLine

Ground

Loop

Fig. 18. Ground Loops

Fig. 19. Single Point Ground

+Vout

-Vout

Load Load

RLine

RLine RLine

RLine

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-29-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Parallel Power Distribution

Figure 20 shows a typical parallel power distri-

bution design. Such designs, sometimes called

daisy chains, can be used for very low output

currents, but are not normally recommended.

The voltage across loads far from the source

can vary greatly depending on the IR drops

along the leads and changes in the loads clos-

er to the source. Dynamic load conditions

increase the potential problems.

Radial Power Distribution

Radial power distribution is the preferred

method of providing power to the load. Figure

21 shows how individual loads are connected

directly to the power source. This arrangement

requires additional power leads, but it avoids

the voltage variation problems associated with

the parallel power distribution technique.

Mixed Distribution

In the real world a combination of parallel and

radial power distribution is often used. Dynamic

and high current loads are connected using a

radial design, while static and low current loads

can be connected in parallel. This combined

approach minimizes the drawbacks of a parallel

design when a purely radial design is not feasi-

ble.

Redundant Operation

A common requirement in high reliability sys-

tems is to provide redundant power supplies.

The easiest way to do this is to place two con-

verters in parallel, providing fault tolerance but

not load sharing. Oring diodes should be used

to ensure that failure of one converter will not

cause failure of the second. Figure 23 shows

such an arrangement. Upon application of

power, one of the converters will provide a

slightly higher output voltage and will support

the full load demand. The second converter will

see a zero load condition and will “idle”. If the

first converter should fail, the second converter

will support the full load. When designing

redundant converter circuits, Shottky diodes

should be used to minimize the forward voltage

drop. The voltage drop across the Shottky

diodes must also be considered when deter-

mining load voltage requirements.

Load 1 Load 2 Load 3

+Vout

-Vout

RL1 RL2

RL3

RG1 RG2

RG3

RL = Lead Resistance

RG = Ground Lead Resistance

Fig.21. Radial Power Distribution

Load 1 Loa

d

+Vout

-Vout

RL1 RL2

RG1 RG2

I1 + I2 + I3I2 + I3

RL

=

Lead Resistance

Fig.20. Parallel Power Distribution

Load 1 Load 2 Load 3

+Vout

-Vout

RL1 RL2

RL3

RG1 RG2

RG3

RL = Lead Resistance

RG = Ground Lead Resistance

Load 4

RL4

RG4

Fig. 22. Mixed Power Distribution

+Vout

-Vout

+Vout

-Vout

Load

Fig. 23. Redundant Operation

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-30-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Thermal Management

T

Technologies

echnologies

AEH 24V input series features high efficiency

and the module have typical efficiency high up

to 88% at full load. With less heat dissipation

and temperature-resistant components such as

ceramic capacitors, these modules exhibit good

behavior during prolonged exposure to high

temperatures. Maintaining the operating case

temperature (Tc) within the specified range help

keep internal-component temperatures within

their specifications which in turn help keep

MTBF from falling below the specified rating.

Proper cooling of the power modules is also

necessary for reliable and consistent operation.

Basic Thermal Management

Measuring the case temperature of the module

(Tc) as the method shown in Figure 24 can ver-

ify the proper cooling. Figure 24 shows the

metal surface of the module and the pin loca-

tions. The module should work under 90°C for

the reliability of operation and TCmust not

exceed 100 °C while operating in the final sys-

tem configuration. The measurement can be

made with a surface probe after the module has

reached thermal equilibrium. If a heat sink is

mounted to the case, make the measurement

as close as possible to the indicated position. It

makes the assumption that the final system

configuration exists and can be used for a test

environment.

The following text and graphs show guidelines

to predict the thermal performance of the mod-

ule for typical configurations that include heat

sinks in natural or forced airflow environments.

Note that Tc of module must always be checked

in the final system configuration to verify proper

operational due to the variation in test condi-

tions.

Thermal management acts to transfer the heat

dissipated by the module to the surrounding

environment. The amount of power dissipated

by the module as heat (PD) is got by the equa-

tion below:

PD= PI˘ PO

where : PIis input power;

POis output power;

PD is dissipated power.

Also, module efficiency (η) is defined as the fol-

lowing equation:

η= PO / PI

If eliminating the input power term, from two

above equations can yield the equation below:

PD = PO(1-η )/η

The module power dissipation then can be cal-

culated through the equation.

Because each power module output voltage

has a different power dissipation curve, a plot of

power dissipation versus output current over

three different line voltages is given in each

module-specific data sheet. The typical power

dissipation curve of AEH series are shown as

figure 25 to figure 30.

29.0 (1.14)

30.5 (1.2)

VI (–)

ON/OFF

CASE

+ SEN

TRIM

– SEN

VI (+)

VO (–)

VO (+)

MEASURE CASE

TEMPERATURE HERE

Top View

Dimensions: millimeters (inches)

Fig.24. Case Temperature Measurement

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-31-

2

2.5

3

3.5

4

4.5

5

5.5

012345678910

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

2

2.5

3

3.5

4

4.5

5

5.5

6

012345678910

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

4

5

6

7

8

9

012345678910

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

3

2

3

4

5

6

7

8

02468101214161820

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

3

4

5

6

7

8

9

10

0 2 4 6 8 101214161820

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

6

8

10

12

14

16

18

0 2 4 6 8 101214161820

Output Current (A)

Power Dissipation (W)

Vin=18V

Vin=24V

Vin=36V

Fig.25. AEH10G24 Power Dissipation Curves

Fig.26. AEH10A24 Power Dissipation Curves

Fig.27. AEH20F24 Power Dissipation Curves

Fig.28. AEH10F24 Power Dissipation Curves

Fig.29. AEH20G24 Power Dissipation Curves

Fig.30. AEH20A24 Power Dissipation Curves

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-32-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Module Derating

Experiment Setup

From the experimental set up shown in figure

31, the derating curves as figure 32 can be

drawn. Note that the PWB ( printed-wiring

board ) and the module must be mounted verti-

cally. The passage has a rectangular cross-

section. The clearance between the facing

PWB and the top of the module is kept 13 mm

(0.5 in.) constantly.

Convection W

Convection Without Heat Sinks

ithout Heat Sinks

Heat transfer can be enhanced by increasing

the airflow over the module. Figure 32 shows

the maximum power that can be dissipated by

the module.

In the test, natural convection airflow was mea-

sured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20

ft./min.). The 0.5 m/s to 4.0 m/s (100 ft./min. to

800 ft./min.) curves are tested with externally

adjustable fans. The appropriate airflow for a

given operating condition can be determined

through figure 32.

Example 1. How to calculate the minimum

airflow required to maintain a desired Tc?

If a AEH20A24 module operates with a 24V line

voltage, a 20 A output current, and a 40 °C

maximum ambient temperature, What is the

minimum airflow necessary for the operating?

Determine PD( referenced Fig.30. ) with con-

dition:

VI= 24 V

lO= 20 A

Get: PD= 15 W

And with TA= 40 °C

Determine airflow ( Fig.32. ):

v = 1.5 m/s (300 ft./min.)

Example 2. How to calculate the maximum

output power of a module in a certain con-

vection and a max. TA?

What is the maximum power output for a

AEH20A24 operating at following conditions:

VI= 24 V;

v = 1.5 m/s (300 ft./min.);

TA= 40 °C.

Determine PD( Fig.32. )

PD= 15W

Determine IO(Fig.30):

IO= 20 A

Calculate PO:

010203040 100

0

21

Local Ambient Temperature, T

A

(°C)

Power Dissipation , P

D

(W)

15

12

6

90

80706050

4.0 m/s (800 ft./min.)

0.1 m/s (20 ft./min.)

Natural Convection

1.0 m/s (200 ft./min.)

2.0 m/s (400 ft./min.)

3.0 m/s (600 ft./min.)

3

9

18 1.5 m/s (300 ft./min.)

0.5 m/s (100 ft./min.)

Fig.32. Forced Convection Power Derating

without Heat Sink

Dimensions: millimeters (inches).

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED

BELOW THE

MODULE

AIRFLOW

19 (0.75)

FACING PWB

MODULE

PWB

76 (3.00)

Fig.31. Experiment Set Up

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-33-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

PO= (VO) x (IO) = 5 x 20 = 100 W

Although the two examples above use 100 ° C

as the maximum case temperature, for

extremely high reliability applications, one may

design to a lower case temperature as shown in

Example 4 on page 35.

Heat Sink Configuration

Several standard heat sinks are available for

the AEH 24Vin 50 W to 150 W modules as

shown in Figure 33 to Figure 35.

The heat sinks mount to the top surface of the

module with screws torqued to 0.56 N-m (5 in.-

lb). A thermally conductive dry pad or thermal

grease is placed between the case and the

heat sink to minimize contact resistance (typi-

cally 0.1°C/W to 0.3°C/W) and temperature dif-

ferential.

Nomenclature for heat sink configurations is as

follows:

WDxyyy40

where:

x = fin orientation: longitudinal (L) or trans

verse (T)

yyy = heat sink height (in 100ths of inch)

For example, WDT5040 is a heat sink that is

transverse mounted (see Figure 35) for a 61

mm x 57.9 mm (2.4 in.x 2.28 in.) module with a

heat sink height of 0.5 in.

Heatsink Mounting Advice

A crucial part of the thermal design strategy is

the thermal interface between the baseplate of

the module and the heatsink. Inadequate mea-

sures taken here will quickly negate any other

attempts to control the baseplate temperature.

For example, using a conventional dry insulator

can result in a case-heatsink thermal imped-

ance of >0.5°C/W, while use one of the rec-

ommended interface methods (silicon grease

or thermal pads available from Avansys) can

57.9 (2.28)

61

(2.4)

1 IN. (WDL10040)

1 1/2 IN. (WDL15040)

1/2 IN. (WDL05040)

Fig.34. Longitudinal Fins Heat Sink

1 IN. (WDT10040)

1 1/2 IN. (WDT15040)

61 (2.4)

1/2 IN. (WDT05040)

57.9

(2.28)

Fig.35. Transverse Fins Heat Sink

89.1(3.51)

57.0

(2.24) 11.8

(0.465)

4.9(0.193)

Dimensions: millimeters (inches).

Fig.33. Non Standard Heatsink

Fig.36. Heat Sink Mounting

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-34-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

result in a case-heatsink thermal impedance

around 0.1°C/W.

Natural Convection with Heat Sink

The power derating for a module with the heat

sinks ( shown as figure 25 to figure 30) in nat-

ural convection is shown in figure 35. In this

test, natural convection generates airflow about

0.05 m/s to 0.1 m/s ( 10ft./min to 20ft./min ).

Figure 37 can be used for heat-sink selection in

natural convection environment.

Example 3. How to select a heat sink?

What heat sink would be appropriate for a

AVE100-24S05 in a natural convection environ-

ment at nominal line, 2/3 load, and maximum

ambient temperature of 40°C?

Determine PD( referenced Fig.30. ) with con-

dition:

VI= 24 V

IO= 2/3 (20) = 13 A

TA= 40 °C

Get: PD= 10.5 W

Determine Heat Sink (Fig.37.):

no heat sink allows up to TA = 30 °C

1/4 in. allows up to TA = 40 °C

Basic Thermal Model

There is another approach to analyze module

thermal performance, to model the overall ther-

mal resistance of the module. This presentation

method is especially useful when considering

heat sinks. The following equation can be used

to calculate the total thermal resistance .

RCA =∆TC, max / PD

Where RCA is the module thermal resistance;

∆TC, max is the maximum case temperature

rise;

PD is the module power dissipation.

In this model, PD, ∆TC, max, and RCA are equals

to current flow, voltage drop, and electrical

resistance, respectively, in Ohm's law, as

shown in Figure 38. Also, ∆TC, max is defined as

the difference between the module case tem-

perature (TC) and the inlet ambient temperature

(TA).

∆TC, max = TC˘ TA

Where TCis the module case temperature;

TA is the inlet ambient temperature.

For AEH 24Vin Series 50W to 150W convert-

ers, the module's thermal resistance values

versus air velocity have been determined

experimentally and shown in figure 39. The

highest values on each curve represents the

point of natural convection.

Figure 39 is used for determining thermal per-

formance under various conditions of airflow

and heat sink configurations.

010203040 90100

0

20

25

30

35

LOCAL AMBIENT TEMPERATURE, TA (°C)

POWER DISSIPATION, P

D

(W)

15

10

5

50 60 70 80

1 1/2 in.

1 in.

1/2 in.

1/4 in.

NONE

Fig.37. Heat Sink Power Derating Curves,

Natural Convection

BMPM

PD

= BMPM

THERMAL

RESISTANCE

Fig.38. Basic Thermal Resistance Model

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-35-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Example 4. How to determine the allowable

minimum airflow to heat sink combinations

necessary for a module under a desired Tc

and a certain condition?

Although the maximum case temperature for

the AEH Series converters is 100°C, you can

improve module reliability by limiting Tc,max to

a lower value. How to decide? For example,

what is the allowable minimum airflow for AEH

100W heat sink combinations at desired Tc of

80 °C?

The working condition is as following:

VI= 24 V, IO= 20 A, TA= 40 °C

Determine PD( Fig.30. )

PD= 15 W

Then solve RCA::

RCA = ∆TC, max / PD

RCA = (TC− TA)/ PD

RCA = (80 − 40)/ 15 = 2.7°C/W

determine air velocity from figure 39:

If no heat sink:

v = 3 m/s (600 ft./min.)

If 1/4 in. heat sink:

v = 2 m/s (400 ft./min.)

If 1/2 in. heat sink:

v = 1.4 m/s (280 ft./min.)

If 1 in. heat sink:

v = 0.5 m/s (100 ft./min.)

Example 5. How to determine case tempera-

ture ( Tc ) for the various heat sink configu-

rations at certain air velocity?

What is the allowable Tc for AEH 24Vin 100W

heat sink configurations at desired air velocity

of 2.0 m/s, and it is operating at a 24 V line volt-

age, a 20 A output current, a 40 °C maximum

ambient temperature?

Determine PD( Fig.30. ) with condition:

VI= 24 V,

IO= 20 A,

TA= 40 °C,

v = 2.0 m/s (400 ft./min.).

Get: PD= 15 W

Determine TC:TC= (RCA x PD) + TA

Determine the corresponding thermal resis-

tances ( RCA ) from Figure 39 :

No heat sink: RCA = 3.8 °C/W

TC= (3.8 x 15) + 40 = 97 °C

1/4 in. heat sink: RCA = 2.8 °C/W

TC= (2.8 x 15) + 40 = 82 °C

1/2 in. heat sink: RCA = 2.0 °C/W

TC= (2.0 x 15) + 40 = 70 °C

1 in. heat sink: RCA = 1.2 °C/W

TC= (1.2 x 15) + 40 = 58 °C

In this configuration, the heat sink would not

need and the power module does not exceed

the maximum case temperature of 100°C.

AEH 24V

AEH 24Vin Series Mechanical

in Series Mechanical

Considerations

Installation

Although AEH 24Vin series converters can be

mounted in any orientation, free air-flowing

must be taken. Normally power components

are always put at the end of the airflow path or

have the separate airflow paths. This can keep

other system equipment cooler and increase

0 0.5

(100) 1.0

(200) 1.5

(300) 2.0

(400) 2.5

(500) 3.0

(600)

0

1

5

6

7

8

Air Velocity m/s (ft./min.)

4

3

2

Case-Ambient Thermal Resistance

R

CA

(°C/W)

1 in. HEAT SINK

1/2 in. HEAT SINK

1/4 in. HEAT SINK

NO HEAT SINK

Fig.39. Case-to-Ambient Thermal

Resistance Curves; Either Orientation

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-36-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

component life spans.

Soldering

AEH 24Vin series converters are compatible

with standard wave soldering techniques.

When wave soldering, the converter pins

should be preheated for 20-30 seconds at

110°C, and wave soldered at 260°C for less

than 10 seconds.

When hand soldering, the iron temperature

should be maintained at 425°C and applied to

the converter pins for less than 5 seconds.

Longer exposure can cause internal damage to

the converter. Cleaning can be performed with

cleaning solvent IPA or with water.

MTBF:

The MTBF, calculated in accordance with

Bellcore TR-NWT-000332 is 1,880,000 hours.

Obtaining this MTBF in practice is entirely pos-

sible. If the ambient air temperature is expected

to exceed +25°C, then we also advise a

heatsink on the AEH, oriented for the best pos-

sible cooling in the air stream.

Avansys can supply replacements for convert-

ers from other manufacturers, or offer custom

solutions. Please contact the Avansys factory

for details.

-Vin

Case

CNT

+Vin +Vout



+Sense

Trim

-Sense

-Vout

5.1 (0.2)

10.16 (0.4)

15.24 (0.6)

4.8 (0.19) 48.26 (1.9)

10.16 (0.4)

7.62 (0.3)

57.9 (2.28)

61.0 (2.4)

mm (inches)

7-

12.7 (0.5)

Mounting Inserts

M3 thru hole x4



2-

φ2.0 (0.09) 



only +Vo and -Vo

φ1.0 (0.04)

all pins except +Vo and -Vo



Length optional

5.8 (0.228) default

Pin Length Option

4.80mm ! 0.5mm

0.189in. ! 0.020in.

3.80mm ! 0.25mm

0.150in. ! 0.010in.

2.80mm ! 0.25mm

0.110in. ! 0.010in.

5.8mm ! 0.5mm

0.228in. ! 0.02in.

Device Code Suffix

-4 

-6

-8

none

Top View

Mechnical chart

AA

AAEE

EEHH

HH

22

2244

44VV

VV

II

IInn

nnpp

ppuu

uutt

tt

HH

HHaa

aall

llff

ff-

-BB

BBrr

rrii

iicc

cckk

kk

SS

SSee

eerr

rrii

iiee

eess

ss

PP

PPoo

ooww

wwee

eerr

rr

CC

CCoo

oonn

nnvv

vvee

eerr

rrtt

ttee

eerr

rrss

ss

22

22..

..55

55VV

VV,,

,,

33

33..

..33

33VV

VV,,

,,

55

55VV

VV

OO

OOuu

uutt

ttpp

ppuu

uutt

tt,,

,,

55

5500

00-

-11

1155

5500

00

WW

WWaa

aatt

tttt

tt

-37-

USA Europe Asia

TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662

FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com

Recommend Hole Pattern

10.16

(0.400)

10.16

(0.400)

12.7 (0.50)

48.3 (1.90)

48.26

(1.900)

4.8

(0.19)

Mounting Inserts

Module Outline

5.1 (0.20)

57

.

9

(2

.

28)

Max

17.78

(0.700)

25.40

(1.000)

35.56

(1.400)

25.40

(1.000)

50.8

(2.00)

35.56

(1.400)

61.0

(2.40)

-VO

-Vin

–Sense

Trim

+Sense

Case

Control

+Vin

I +VO

Max