AVO50-48S2V5P-4 - Artesyn Embedded Technologies

AVO50 Series DC/DC Converter TRN

TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 1/34

BOM:31020684 DATE: 2008-07-17 REV1.2

AVO50 Series DC/DC Converter

Technical Reference Notes

Industry Standard Eighth Brick: 36~75V Input, 1.2V~12V Single Output

Industry standard eighth brick: 2.28”

×

0.9’’

×

0.35’’

Options

• Choice of positive logic or negative logic

for CNT function

• Choice of short pins or long pins

Description

The AVO50 series DC/DC converter (for short, converter) is a new open frame DC/DC converter for

optimum efficiency and power density. The converter provides up to 25A output current, which

makes it an ideal choice for small space, high current and low voltage applications. The converter

uses an industry standard eighth brick: 57.9mm × 22.9mm × 8.9mm (2.28” × 0.9” × 0.35”) and

standard pinout configuration, and provide CNT and trim functions. The converters can provide

1.2V to 12V single output. Outputs are isolated from inputs. The converter can achieve ultra high

efficiency. For most applications, a heat sink is not required.

Features

• Delivers up to 25A output current

• Industry standard eighth brick foot print

57.9mm × 22.9mm × 8.9mm

(2.28” × 0.9” × 0.35”)

• Basic isolation

• Ultra high efficiency: 91% at 5V full load

(Vin = 48Vdc)

• Improved thermal performance:

full load at 55ºC at 1m/s (200LFM) for 5Vo

• High power density

• Low output noise

• 2:1 wide input voltage of 36V-75V

• CNT function

• Remote sense

• Trim function: +10%/-20%

• Input under-voltage lockout

• Output over-current protection

• Output over-voltage protection

• Over-temperature protection

• RoHS compliant

AVO50 Series DC/DC Converter TRN

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Converter Numbering

AVO 50 -48 S 1V5 P - 4

Pin length: Omit for 5.8 mm

±

0.5mm (0.228in.

±

0.02in.)

-4---4.8 mm

±

0.5mm (0.189in.

±

0.02in.)

-6---3.80mm

±

0.25mm(0.150in.

±

0.010in.)

-8---2.80mm

±

0.25mm(0.110in.

±

0.010in.)

CNT logic, P---positive logic control,

default is negative logic control

Output rated voltage: 1V2--1.2V, 1V5--1.5V, 1V8--1.8V,

2V5--2.5V, 3V3--3.3V, 05--5V, 12--12V

Output number: S ---single output, D---dual output

Input rated voltage

Output rated power: Power digit based on maximum

output power. The lower output is limited by its current

Series name

AVO50 Series DC/DC Converter TRN

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Electrical Specifications

Unless otherwise indicated, specifications apply over all operating input voltage and temperature

conditions. Standard test condition on a single converter is as follows:

Tc (board): 25 °C

+Vin: 48V ± 2%

-Vin: return pin for +Vin

CNT: connected to -Vin for negative logic

open for positive logic

+Vout: connected to load

-Vout: connected to load (return)

+Sense: connected to +Vout

-Sense: connect edto -Vout

Trim(Vadj): open

Input Specifications

Parameter Symbol Min Typ Max Unit

Operating Input Voltage V

I

36 48 75 V

DC

Maximum Input Current

(V

I

= 0 to V

I,max

, Io = Io,max)

I

I,max

- - 2.5 A

Input Reflected-ripple Current

(5Hz to 20MHz, 12uH source impedance, T

A

=

25 ºC)

I

- - 20 mAp-p

Supply Voltage Rejection

(1kHz) - 50 60 - dB

CAUTION: The converters have no internal fuse. An input line fuse must always be used.

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Absolute Maximum Ratings

Stresses in excess of the absolute maximum ratings can cause permanent damage to the device.

These are absolute stress ratings only. Functional operation of the device is not implied at these or

any other conditions in excess of those given in the operational sections of the IPS. Exposure to

absolute maximum ratings for extended periods can adversely affect device reliability.

Parameter Device

Symbol

Min

Typ Max Unit

Continuous All V

I

0 - 75 Vdc

Input Voltage

Transient

(100ms)

All V

I, trans

0 - 100 Vdc

Operating Ambient Temperature

(See Thermal Consideration)

All Ta -40 - 85 °C

Operating Board Temperature All Tc - - 100 °C

Storage Temperature All T

STG

-55 - 125 °C

Operating Humidity All - - - 85 %

Basic Input-Output Isolation

(Conditions:

1mA for 60 sec

, slew rate

of 1500V/10sec)

All - 2000 Vdc

Output Power

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

Po,max 0 -

24

30

36

50

49.5

50

W

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Output Specifications

Parameter Device Symbol Min Typ Max Unit

Output Ripple and Noise

Peak-to-Peak (5Hz to 20

MHz)

(Across 1µF @10V, X7R

ceramic capacitor & 470µF

@10V LOW ESR

Aluminum capacitor)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

50

55

45

50

55

- mVp-p

External Load Capacitance

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- 220 470

10,000

5000

1000

µF

Output Voltage Setpoint

(VI = VI,min to VI,max: Io =

Io,max; Ta = 25 °C )

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

V

o,set

1.18

1.48

1.77

2.46

3.25

4.95

11.85

1.2

1.5

1.8

2.5

3.3

5

12

1.22

1.52

1.83

2.54

3.35

5.05

12.15

Vdc

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Parameter Device Symbol Min Typ Max Unit

Line (V

i,min

to

V

i,max

)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

1

4

9

- mV

Load (Io,min

to Io,max)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

1

5

- mV

Output

Regulation

Temperature

(Tc = -40°C

to +100°C)

All - - - 0.02 %Vo/°C

Rated Output Current

1.2V,

1.5V

1.8V

2.5V

3.3V

5V

12V

Io 0 -

20

15

10

4.2

A

Output Current-limit

Inception

(Hiccup)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

Io

22

16.5

11

4.6

-

28

21

14

7.0

A

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Parameter Device Symbol Min Typ Max Unit

Efficiency

(V

I

= V

I,nom

; 100%I

o,max

; T

A

= 25°C)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

88

87

89

90

91

- %

Efficiency

(V

I

= V

I,nom

; 50%I

o,max

; T

A

= 25°C)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

86

88

91

90

89

- %

Output Specifications (Cont)

Parameter Device

Symbol

Min Typ

Max

Unit

Load Change from Io

= 50% to 75% to

50% Io,max

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

60

40

50

95

100

150

- mV

Dynamic

Response

(∆Io/∆t =

1A/10µs, VI =

V

I,nom

; Ta =

25°C) Peak Deviation

Settling Time

(to V

o,nom

)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

- -

300

110

105

60

120

- µsec

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Parameter Device

Symbol

Min Typ

Max

Unit

Load Change from Io

= 50% to 75% to

50% Io,max

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

-

130

110

150

130

180

- mv

Dynamic

Response

(∆Io/∆t = 1A/1µs;

VI = V

I,nom

; Ta =

25°C, additional

220µF load

capacitor) Peak Deviation

Settling Time (to

V

o,nom

)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

-

300

100

110

130

80

130

300

- µsec

Turn-On Time (Io = Io,max ; Vo within

1%) All - - - 20 msec

Output Voltage Overshoot

(Io = Io,max ; T

A

= 25°C)

All - - 0 %Vo

Switching Frequency All - 310

kHz

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Feature Specifications

Parameter

Device

Symbo

l Min Typ Max Unit

Logic Low All -0.7 - 1.2 V

Enable pin voltage

Logic High All 3.5 - 12 V

Logic Low All - - 1.0 mA

Enable pin current

(leakage current,

@10V) Logic High All - - - µA

Output Voltage Adjustment

Range All* - 80 110 %Vo

Output Over-voltage

(Hiccup)

1.2V

1.5V

1.8V

2.5V

3.3V

5V

12V

Vo

clamp

1.4

1.8

2.2

3.0

3.9

6.0

14.4

-

2.0

2.5

3.0

3.8

5.0

7.5

18

V

Over-temperature Protection

(Auto-recovery) All 110 120 135 C

Turn-on Point All - 31 34 36 V

Under-voltage

Lockout Turn-off Point All - 30 33 35 V

Isolation Capacitance All - - 1000 - PF

Isolation Resistance All - 10 - - MΩ

Calculated MTBF

(Io = Io,max ; Tc = 25°C)

All - - 2,500,000

- Hours

Weight All - - - 30 g(oz.)

Output Voltage Adjustment Rang of 12V converter is 90% to 110%.

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Characteristic Curves

70

75

80

85

90

0 2 4 6 8 10 12 14 16 18 20

Load(A)

Effiency(%)

Vin=36V

Vin=48V

Vin=75V

55

60

65

70

75

80

85

90

0 5 10 15 20 25

Load (A)

Efficiency (%)

36V

48V

75V

Fig.1 Typical efficiency of AVO50-48S1V2 Fig.2 Typical efficiency of AVO50-48S1V5

70

75

80

85

90

0 2 4 6 8 10 12 14 16 18 20

Load(A)

Effiency(%)

Vin=36V

Vin=48V

Vin=75V

70

75

80

85

90

95

0 5 10 15 20

Load(A)

Effiency(%)

Vin=36V

Vin=48V

Vin=75V

Fig.3 Typical efficiency of AVO50-48S1V8 Fig.4 Typical efficiency of AVO50-48S2V5

75

80

85

90

95

2 4 6 8 10 12 14 16 18 20

Load (A)

Ef f icienc y(%)

36V

48V

75V

70

75

80

85

90

95

0 2 4 6 8 10

Load(A)

Effiency(%)

Vin=36V

Vin=48V

Vin=75V

Fig.5 Typical efficiency of AVO50-48S3V3 Fig.6 Typical efficiency of AVO50-48S05

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60

65

70

75

80

85

90

95

0 0.5 1 1.5 2 2.5 3 3.5 4

Output current(A)

Effiency(%)

Vin=36V

Vin=48V

Vin=75V

Fig.7 Typical efficiency of AVO50-48S12

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 5 10 15 20 25 30

Output Current (A)

Output Voltage (V)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20 25 30 35 40

Output current (A)

Output voltage (V)

Fig.8 Typical output over-current of AVO50-48S1V2 Fig.9 Typical output over-current of AVO50-48S1V5

0

0.3

0.6

0.9

1.2

1.5

1.8

0 5 10 15 20 25 30

Output Current (A)

Output Voltage (V)

0

0.5

1

1.5

2

2.5

3

0 5 10 15 20 25 30

Output Current (A)

Output Voltage (V)

Fig.10 Typical output over-current of AVO50-48S1V8 Fig.11 Typical output over-current of AVO50-48S2V5

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0

0.5

1

1.5

2

2.5

3

3.5

0 5 10 15 20 25 30 35 40

Output Current（A）

Output Voltage（V）

0

1

2

3

4

5

6

0 3 6 9 12 15

Output Current (A)

Output Voltage (V)

Fig.12 Typical output over-current of AVO50-48S3V3 Fig.13 Typical output over-current of AVO50-48S05

Fig.14 Typical output over-current of AVO50-48S12

0

1

2

3

4

0 2 4 6 8 10 12 14 16 18 20

Load(A)

Dissipation(W)

Vin=36V

Vin=48V

Vin=75V

0

1

2

3

4

5

6

7

0 5 10 15 20 25

Load (A)

Power dissipation (W)

36V

48V

75V

Fig.15 Typical power dissipation of AVO50-48S1V2 Fig.16 Typical power dissipation of AVO50-48S1V5

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0

1

2

3

4

5

0 2 4 6 8 10 12 14 16 18 20

Load(A)

Dissipation(W)

Vin=36V

Vin=48V

Vin=75V

0

1

2

3

4

5

6

7

0 5 10 15 20

Load(A)

Dissipation(W)

Vin=36V

Vin=48V

Vin=75V

Fig.17 Typical power dissipation of AVO50-48S1V8 Fig.18 Typical power dissipation of AVO50-48S2V5

0

2

4

6

8

2 4 6 8 10 12 14 16 18 20

Load (A)

Pow er Dissipation (W)

36V

48V

75V

0

1

2

3

4

5

6

0 2 4 6 8 10

Load(A)

Dissipation(W)

Vin=36V

Vin=48V

Vin=75V

Fig.19 Typical power dissipation of AVO50-48S3V3 Fig.20 Typical power dissipation of AVO50-48S05

0

1

2

3

4

5

6

7

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Output current(A)

Dissipation(W)

Vin=36V

Vin=48V

Vin=75V

Fig.21 Typical power dissipation of AVO50-48S12

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Fig.22 AVO50-48S1V2 typical transient response fig.23 AVO50-48s1V2 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

Fig.24 AVO50-48S1V5 typical transient response Fig.25 AVO50-48S1V5 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆io/∆t = 1A/1µs) (∆io/∆t = 1A/1µs)

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Fig.26 AVO50-48S1V5 typical transient response Fig.27 AVO50-48S1V5 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆io/∆t = 0.1A/1µs) (∆io/∆t = 0.1A/1µs)

Fig.28 AVO50-48S1V5 typical transient response Fig.29 AVO50-48S1V5 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

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Fig.30 AVO50-48S1V8 typical transient response Fig. 31 AVO50-48S1V8 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

Fig.32 AVO50-48S1V8 typical transient response Fig.33 AVO50-48S1V8 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

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Fig.34 AVO505-48S2V5 typical transient response Fig. 35 AVO50-48S2V5 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

Fig.36 AVO50-48S2V5 typical transient response Fig.37 AVO50-48S2V5 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

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Fig.38 AVO50-48S3V3 typical transient response Fig. 39 AVO50-48S3V3 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

Fig.40 AVO50-48S3V3 typical transient response Fig.41 AVO50-48S3V3 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

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Fig.42 AVO50-48S05 typical transient response Fig. 43 AVO50-48S05 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

Fig.44 AVO50-48S05 typical transient response Fig.45 AVO50-48S05 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

Fig.46 AVO50-48S12 typical transient response Fig. 47 AVO50-48S12 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 0.1A/1µs) (∆Io/∆t = 0.1A/1µs)

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Fig.48 AVO50-48S12 typical transient response Fig.49 AVO50-48S12 typical transient response

to step decrease in load from 50% to 25% to step increase in load from 50% to 75%

of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input

(∆Io/∆t = 1A/1µs) (∆Io/∆t = 1A/1µs)

Fig.50 Typical output ripple voltage of AVO50-48S1V2 Fig.51 Typical output ripple voltage of AVO50-48S1V5

room temperature, Io = Io,max room temperature, Io = Io,max

Fig.52 Typical output ripple voltage of AVO50-48S1V8 Fig.53 Typical output ripple voltage of AVO50-48S2V5

room temperature, Io = Io,max room temperature, Io = Io,max

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Fig.54 Typical output ripple voltage of AVO50-48S3V3 Fig.55 Typical output ripple voltage of AVO50-48S05

room temperature, Io = Io,max room temperature, Io = Io,max

Fig.56 Typical output ripple voltage of AVO50-48S12

room temperature, Io = Io,max

Fig.57 AVO50-48S1V2 typical start-up from power on Fig.58 AVO50-48S1V2 typical start-up from CNT on

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Fig.59 AVO50-48S1V5 typical start-up from power on Fig.60 AVO50-48S1V5 typical start-up from CNT on

Fig.61 AVO50-48S1V8 typical start-up from power on Fig.62 AVO50-48S1V8 typical start-up from CNT on

Fig.63 AVO50-48S2V5 typical start-up from power on Fig.64 AVO50-48S2V5 typical start-up from CNT on

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Fig.65 AVO50-48S3V3 typical start-up from power on Fig.66 AVO50-48S3V3 typical start-up from CNT on

Fig.67 AVO50-48S05 typical start-up from power on Fig.68 AVO50-48S05 typical start-up from CNT on

Fig.69 AVO50-48S12 typical start-up from power on Fig.70 AVO50-48S12 typical start-up from CNT on

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Feature Description

CNT Function

The converter is equipped with a primary

ON/OFF pin used to remotely turn the

converter on or off via a system signal. Two

CNT logic options are available. For the

positive logic model a system logic low signal

will turn the converter off. For the negative logic

model a system logic high signal will turn the

converter off. For negative logic models where

no control signal will be used the ON/OFF pin

should be connected directly to -Vin to ensure

proper operation. For positive logic models

where no control signal will be used the

ON/OFF pin should be left unconnected.

The following figure shows a few simple CNT

circuits.

Fig.71 CNT circuits

Remote Sense

The converter can remotely sense both lines of

its output which moves the effective output

voltage regulation point from the output

terminals of the converter to the point of

connection of the remote sense pins. This

feature automatically adjusts the real output

voltage of the converters in order to

compensate for voltage drops in distribution

and maintain a regulated voltage at the point of

load.

When the converter is supporting loads far

away, or is used with undersized cabling,

significant 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 adequately sized cabling is used. When

this is not possible, the converter can

compensate for a drop of up to 10%Vo, through

use of the sense leads.

When used, the + Sense and - Sense leads

should be connected from the converter to the

point of load as shown in Fig.72, using twisted

pair wire, or parallel pattern to reduce noise

effect. The converter will then regulate its

output voltage at the point where the leads are

connected. Care should be taken not to

reverse the sense leads. If reversed, the

converter will trigger OVP protection.

When not used, the +Sense lead must be

connected with +Vo, and -Sense with -Vo.

Although the output voltage can be increased

by both the remote sense and by the trim, the

maximum increase for the output voltage is not

the sum of both.

The maximum increase is the larger of either

the remote sense or the trim.

Note that at elevated output voltages the

maximum power rating of the converter

remains the same, and the output current

capability will decrease correspondingly.

Fig.72 Sense connections

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Trim

The +Vo output voltage of the converter can be

trimmed with the trim pin provided. Applying a

resistor to the trim pin through a voltage divider

from the output will cause the +Vo output to

increase by up to 10% or decrease by up to

20%. Trimming up by more than 10% of the

nominal output may activate the OVP circuit or

damage the converter. Trimming down more

than 20% can cause the converter to regulate

improperly. If the trim pin is not needed, it

should be left open.

Trim up

With an external resistor connected between

the TRIM and +SENSE pins, the output voltage

set point increases (see Fig.73).

Fig.73 Trim up circuit

The following equation determines the required

external-resistor value to obtain a percentage

output voltage change of 1%.

For Output Voltage: 1.5V ~ 12V

(

)

)(2.10

%

510

%

225

.

1

%1001.5 Ω−

∆

−

∆

×

∆

+

×

=

−

K

V

R

nom

upadj

For Output Voltage: 1.2V

(

)

)(2.10

%

510

%

6

.

0

%1001.5 Ω−

∆

−

∆

×

∆

+

×

=

−

K

V

R

nom

upadj

Note: △= (V

nom

-Vo) × 100/V

nom

V

trim

tolerance: < ±2%

R

adj

tolerance : ±1%

For example: to trim up the output of

AVO75-48S1V8 to 1.98V:

△=(1.98-1.8) × 100/1.8=10

(

)

)(2.10

10

510

10

225

.

1

101008.11.5 Ω−−

×

+

×

=

−

KR

upadj

)(23.21 Ω=

−

KR

upadj

Trim down

With an external resistor between the TRIM

and -SENSE pins, the output voltage set point

decreases (see Fig.74).

Fig.74 Trim down circuit

The following equation determines the required

external-resistor value to obtain a percentage

output voltage change of 1%.

For Output Voltage: 1.2V ~ 12V

)(2.10

%

510 Ω−

∆

=

−

KR

downadj

Note: △= (V

nom

-Vo) × 100/V

nom

Vtrim tolerance: <±2%

Radj tolerance: ±1%

For example: to trim down the output to 1.62V,

△=(1.8-1.62) × 100/1.8=10

)(2.10

10

510 Ω−=

−

KR

downadj

)(8.40 Ω=

−

KR

downadj

Although the output voltage can be increased

by both the remote sense and by the trim, the

maximum increase for the output voltage is not

the sum of both. The maximum increase is the

larger of either the remote sense or the trim.

Note that at elevated output voltages the

maximum power rating of the converter

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remains the same, and the output current

capability will decrease correspondingly.

Minimum Load Requirements

There is no minimum load requirement for the

converter.

Output Capacitance

High output current transient rate (high di/dt) of

change loads might require high values of

output capacitance to supply the instantaneous

energy requirement to the load. To minimize

the output voltage transient drop during this

transient, low Equivalent Series Resistance

(ESR) capacitors may be required, since a high

ESR will produce a correspondingly higher

voltage drop during the current transient.

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 C1 across the output as shown in

Fig.75. The recommended value for the output

capacitor C1 is 470µF.

Fig.75 Output ripple filter

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

conditions C1 can be added across the load,

with a 1µF ceramic capacitor C2 in parallel

generally as shown in Fig.76.

Fig.76 Output ripple filter for a distant load

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 10µF tantalum or ceramic

capacitor in parallel 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 Fig.77. Multiple ground

points can have slightly different potentials 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 connection as shown in Fig.78.

-Vo

+Vo

Load Load

R

Line

R

Line

R

Line

R

Line

R

Line

R

Ground

Loop

Fig.77 Ground loops

AVO50 Series DC/DC Converter TRN

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-Vo

+Vo

Load Load

R

Line

R

Line

R

Line

R

Line

R

Line

Fig.78 Single point ground

Output Over-current Protection

The converter feature foldback current limiting

as part of their Over-current Protection (OCP)

circuits. When output current exceeds 110 to

140% of rated current, such as during a short

circuit condition, the converter will work on

intermittent mode, also can tolerate short circuit

conditions indefinitely. When the over-current

condition is removed, the converter will

automatically restart.

Output Over-Voltage Protection

The output over-voltage protection consists of

circuitry that monitors the voltage on the output

terminals. If the voltage on the output terminals

exceeds the over voltage protection threshold,

then the converter will work on intermittent

mode. When the over-voltage condition is

removed, the converter will automatically

restart.

The protection mechanism is such that the

converter can continue in this condition until

the fault is cleared.

Over-Temperature Protection

The converter features an over-temperature

protection circuit to safeguard against thermal

damage. The converter will work on intermittent

mode when the maximum device reference

temperature is exceeded. When the

over-temperature condition is removed, the

converter will automatically restart.

Design Consideration

Typical Application

LOAD

+VIN

-VIN

CNT1

+VOUT

-VOUT

+SENSE

-SENSE

TRM

F1

Cin

Vin

Co1 Co2

S1

Fig.79 Typical application

F1: Fuse. Use external fuse with a rating of 5A

(fast blow type) for each converter.

Cin: Recommended input capacitor. Use

47µF/100V high frequency low ESR electrolytic

type capacitor.

Co1: Recommended 1µF /10V ceramic

capacitor

Co2: Recommended output capacitor

Use 470µF/10V high frequency low ESR

electrolytic type capacitor.

If Ta<-5 C, use 220µF tantalum capacitor

parallel with a 470µF/ 10V high frequency low

ESR electrolytic capacitor.

Note: The converter cannot be used in parallel

mode directly!

Fusing

The converter has 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 is 5A.

Note: the fuse is fast blow type.

AVO50 Series DC/DC Converter TRN

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Input Reverse Voltage 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

Fig.80. In both cases the diode used is rated

for 10A/100V. Placing the diode across the

inputs rather than in-line with the input offers an

advantage in that the diode only conducts in a

reverse polarity condition, which increases

circuit efficiency and thermal performance.

Fig.80 Reverse polarity protection circuit

AVO50 Series DC/DC Converter TRN

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EMC

For conditions where EMI is a concern, a

different input filter can be used. Fig.81 shows

a filter designed to reduce EMI effects. The

converter can meet EN55022 CLASSA.

-Vin

+Vin +Vout

-Vout

CY8

CX2

CY5CY7

CY2

CY1 U

+Sense

CNT

Vout+Vin+

-Sense

Vin- Vout-

Trim

CX1

CY10

CY6

CY9

Cin1

**

L1

CY3

CY4

Cout2Cout1

Fig.81 EMI reduction filter

Recommended values:

Component Value/Rating

CY1, CY2, CY5,

CY6 4700PF/250VAC

CX1 2.2µ/100V

CY7, CY8, CY9,

CY10 1000PF/250VAC

CY3, CY4 0.47µ

Cin1 47µ/100V

CX2 1u/100V

Cout1 470µ/10V (low ESR

capacitor)

Cout2 1µ/10V

L1 1.8mH

Safety Consideration

For safety-agency approval of the system in

which the converter is used, the converter 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

isolation is a basic insulation. The converter

should be installed in end-use equipment, in

compliance with the requirements of the

ultimate application, and is intended to be

supplied by an isolated secondary circuit.

When the supply to the converter meets all the

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

considered to remain within SELV limits (level

3). If connected to a 60Vdc power system,

double or reinforced insulation must be

provided in the converter that isolates the input

from any hazardous voltages, including the AC

mains. One input pin and one output pin are to

be grounded or both the input and output pins

are to be kept floating. Single fault testing in the

converter must be performed in combination

with the converter to demonstrate that the

output meets the requirement for SELV. The

input pins of the converter are not operator

accessible.

AVO50 Series DC/DC Converter TRN

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Note: Do not ground either of the input pins of

the converter, without grounding one of the

output pins. This may allow a non-SELV

voltage to appear between the output pin and

ground.

Note:

To comply with the published safety standards,

the following must be observed when using this

built-in converter.

1. The converter is intended for use as a

component part of other equipment. When

installing the converter and marking input and

output connections, the relevant safety

standards e.g. UL 60950-1; IEC 60950-1/VDE

0805;EN60950-1;

CAN/CSA-22.2NO.60950-1-03 must be

complied with, especially the requirements for

creepage distances, clearances and distance

through insulation between primary and earth

or primary and secondary.

2. The output power taken from the built-in

converter must not exceed the rating given on

the converter.

3. The converter is not intended to be repaired

by service personnel in case of failure or

component defect.

4. The maximum ambient temperature around

the converter must not exceed 55°C.

5. An external forced air cooling (CFM: 80.2,

Speed: 1m/s, distance from the converter:

20cm) shall be used for converter operates

with full load and ambient up to 55°C.

6. The converter has no in-line fuse. For safety

purpose, a fast acting UL listed fuse or UL

recognized fuse rated 5A/250V needs to be

connected to the input side as external

protection.

Thermal Consideration

Thermal management is an important part of

the system design. The converter has ultra

high efficiency at full load, and the converter

exhibit good performance during pro-longed

exposure to high temperatures. However, to

ensure proper and reliable operation, sufficient

cooling of the converter and power derating is

needed over the entire temperature range of

the converter. Considerations includes ambient

temperature, airflow and converter power

derating.

Measuring thermal reference point of the

converter as the method shown in Fig.82 can

verify the proper cooling.

Notice: The thermocouple must not touch the

pads of the thermistor

Thermocouple

Thermistor

Thermocouple

location

Fig.82 Temperature measurement location

Converter Derating

With 48V input, 55°C ambient temperature, and

200LFM airflow, the converter is rated for full

power. For operation above ambient

temperature of 55°C, the output power must be

derated as shown in Fig.83 to Fig.89,.

Meantime, airflow at least 200LFM over the

converter must be provided to make the

converter working properly.

It is recommended that the temperature of the

thermal reference point be measured using a

thermocouple. Temperature on the PCB at the

thermocouple location shown in Fig. 82 should

AVO50 Series DC/DC Converter TRN

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not exceed 125°C in order to operate inside the

derating curves as shown Fig. 83 to Fig.89.

The use of output power derating curve is

shown in the following example.

Example

What is the minimum airflow necessary for

AVO50-48S3V3 operating at VI = 48V, an

output current of 20A, and a maximum ambient

temperature of 55°C?

Solution

Given: VI = 48V, Io = 20A, Ta = 55°C

Determine airflow (v) (use Fig.83 to 89): v =

1m/sec. (200ft./min.)

0

5

10

15

20

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.83 AVO50-48S1V2 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

0

5

10

15

20

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.84 AVO50-48S1V5 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

0

5

10

15

20

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.85 AVO50-48S1V8 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

0

4

8

12

16

20

25 40 55 70 85

TEMPERATURE, Ta (℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.86 AVO50-48S2V5 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

0

3

6

9

12

15

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.87 AVO50-48S3V3 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

AVO50 Series DC/DC Converter TRN

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0

2

4

6

8

10

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.88 AVO50-48S05 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

25 40 55 70 85

TEMPERATURE, Ta (℃

℃℃

℃)

Output Current Io (A)

2m/s

1.5m/s

1m/s

0.5m/s

0m/s

Fig.89 AVO50-48S12 output power derating

Airflow direction from -VIN to +VIN; VIN = 48V

MTBF

The MTBF, calculated in accordance with

Bellcore TR-NWT-000332, is 2,500,000 hours.

Obtaining this MTBF in practice is entirely

possible. If the board temperature is expected

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

oriented for the best possible cooling in the air

stream.

Emerson can supply replacements for

converters from other manufacturers, or offer

custom solutions. Please contact the factory for

details.

Mechanical

Considerations

Installation

Although the 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 component life

spans.

Soldering

The converter is 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.

AVO50 Series DC/DC Converter TRN

TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 33/34

Mechanical Chart

(Top & pin side view)

57.9[2.28]

50.80[2.000]

TOP VIEW

Φ1.0

7.62[0.300]

1

2

3

See Note 2

±0.10

See note 3

Φ1.5

±0.10

8.9[0.35]

Φ2.0

±0.1

Device

Code Suffix

Pin Length Option

NONE

-4

-6

-8

L

TOLERANCES: XXmm=+/-0.5mm

X.XXmm=+/-0.25mm

4.8mm+/-0.5mm

3.8mm+/-0.5mm

2.8mm+/-0.25mm

5.8mm+/-0.5mm

22.9[0.90]

15.24[0.600]

4

5

6

7

8

L

8.9[0.35]

Notes:

1. Un-dimensioned components are for visual reference only.

2. Pins 1~3, 5~7 are 1.0mm diameter with 2.0mm diameter standoff shoulders.

3. Pin 4 and pin 8 are 1.5mm diameter with no standoff shoulders.

Pin No. Function Pin No. Function

1 +Vin 4 +Vo

2 CNT 5 +Sense

3 -Vin 6 Trim

7 -Sense

8 -Vo

AVO50 Series DC/DC Converter TRN

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Ordering Information

Ripple and Noise

(mV pp)

Model Number

Input

Voltage

(V)

Output

Voltage

(V)

Output

Current

(A) Typ.

Efficiency

(%)

Typ.

AVO50-48S1V2 36

~

75 1.2 20 0 86

AVO50-48S1V5 36

~

75 1.5 20 0 88

AVO50-48S1V8 36

~

75 1.8 20 0 88.5

AVO50-48S2V5 36

~

75 2.5 20 60 89.5

AVO50-48S3V3 36

~

75 3.3 15 0 91

AVO50-48S05 36

~

75 5 10 0 91

AVO50-48S12 36

~

75 12 4.2 90 91

有毒有害物质或元素标识表

有毒有害物质或元素标识表有毒有害物质或元素标识表

有毒有害物质或元素标识表

有毒有害物质或元素

有毒有害物质或元素有毒有害物质或元素

有毒有害物质或元素

铅

铅铅

铅汞

汞汞

汞镉

镉镉

镉六价铬

六价铬六价铬

六价铬多溴联苯

多溴联苯多溴联苯

多溴联苯多溴联苯醚

多溴联苯醚多溴联苯醚

多溴联苯醚

部件

部件部件

部件

名称

名称名称

名称 Pb Hg Cd Cr6＋

＋＋

＋ PBB PBDE

制成板 ○ ○

○

○：表示该有毒有害物质在该部件所有均质材料中的含量在 SJ/T-11363-2006 规定的限量要求以下。

×：表示该有毒有害物质至少在该部件的某一均质材料中的含量超出 SJ/T-11363-2006 规定的限量要求

艾默生网络能源有限公司一直致力于设计和制造环保的产品，我们会通过持续的研究来减少和消除产品中的有毒有害

物质。以下部件或应用中含有有毒有害物质是限于目前的技术水平无法实现可靠的替代或者没有成熟的解决方案：

1

．

焊料（含器件的高温焊料）中含有铅

。

2

．

电子器件的玻璃中含有铅

。

3

．

插针的铜合金中含有铅

适用范围：

AVO50

系列

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Emerson Network Power:

AVO50-48S1V5-4 AVO50-48S1V2-4 AVO50-48S2V5P-4 AVO50-48S12-6L AVO50-48S1V8-4 AVO50-48S05-4

AVO50-48S1V8P-4 AVO50-48S1V2P-4 AVO50-48S12P-4 AVO50-48S2V5-4 AVO50-48S1V5P-4