Technical Reference Notes
Hercules (AEH/ALH60) Open
Frame or HS Adapted
MODEL: AEH/ALH60F48 SHEET 1 OF 21
SEPTEMBER 26, 2002 - REVISION 02
AEH60F48 /ALH60F48 Isolated DC/DC Converter Module
Industry Standard ½ Brick – 36-75V Input, 3.3V / 60A Output
The AEH60F48 / ALH60F48 is part of Astec’s New Ultra High Density ½ Brick family capable of running 60Amps at 3.3V
output. With Efficiencies up to 92% typical at 3.3V - 60Amps, this product provides a 1% to 2% performance increase in
efficiency over the leading 60Amp competitors and up to 10% higher output current. The operating temperature range (-
40°C to 85°C for the ALH; -40°C to 100°C baseplate for AEH) assures maximum application flexibility. New single-
output models feature superior transient response with excellent stability in high capacitance/low ESR load applications.
This family has an effective thermal adapter plate which allows for heat sinking under particularly harsh conditions.
Without the adapter plate (ALH60) provides a very effective low profile which performs extremely well in convection
cooled applications.
Environmental Specifications
•Operating temperature:
-40°C to +85°C for Open Frame (ALH60)
-40°C to +100°C (Baseplate) for (AEH60)
•Storage temperature: -40°C to +125C
•MTBF: >1 million hours
Electrical Parameters
Input
Input range 36-75 VDC
Input Surge 100V / 100ms
Efficiency 91%@3.3V (Typical @ 60
Amps)
Control
Enable TTL compatible
(Positive & Negative enable options)
Output
Regulation
(Line, Load, Temp) <2%
Ripple and Noise 2% typical (100mV p-p
max)
Remote Sense Up to 10%Vout
Output Voltage
Adjust Range ±10% of nominal output
Transient Response 150mV max deviation with
50% to 75% full load
300 µS (max) recovery
Over Voltage
Protection 130% nominal
Special Features
•High efficiency, 92% (30-70%Load))
•-40°C to 100°C baseplate operating temp
•Open Frame version also available
(ALH60)
•Positive and Negative enable function
•Low output ripple and noise
•High capacitive load limit
•Remote sense compensation
•Regulation to zero load
•Fixed frequency switching (190 KHz)
Safety
§ UL, cUL 60950 Recognized
§ EN 60950 through TUV-PS
Industry Standard
½ Brick Package
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 2 OF 21
SEPTEMBER 26, 2002 - REVISION 02
AEH60 / ALH60 SERIES
THIS SPECIFICATION COVERS THE REQUIREMENTS
FOR AN INDUSTRY STANDARD HALF BRICK (MAX 198W @ 3.3V) SINGLE OUTPUT ULTRA HIGH
EFFICIENCY ISOLATED DCDC CONVERTER
MODEL NAME / SIS CODE Construction Vout, Iout
AEH60F48 HS Adapter 3.3V/60A
AEH60G48 HS Adapter 2.5V/60A
AEH60Y48 HS Adapter 1.8V/60A
AEH60K48 HS Adapter 1.2V/60A
ALH60F48 Open Frame 0.4” 3.3V/60A
ALH60G48 Open Frame 0.4” 2.5V/60A
ALH60Y48 Open Frame 0.4” 1.8V/60A
ALH60K48 Open Frame 0.4” 1.2V/60A
Options:Suffix
Negative Enable: "N"
Positive Enable: no suffix
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 3 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Electrical Specifications
STANDARD TEST CONDITION on a single unit, unless otherwise specified.
TA:25°C (Ambient Air)
+VIN:48V ± 2%
-VIN:Return pin for +VIN
Enable: Open (Positive Enable)
+VOUT:Connect to Load
-VOUT:Connect to Load (return)
Trim (VADJ): Open
+Sense: Connect to +VOUT
-Sense: Connect to -VOUT
ABSOLUTE MAXIMUM RATINGS
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. 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 specs. Exposure to absolute maximum ratings for extended periods can adversely affect device
reliability.
Parameter Device Symbol Min Typ Max Unit
Input Voltage:
Continuous:
Transient (100ms) All
All VI
VI, trans
0
0-
-75
100 Vdc
Vdc
Operating Temperature AEH
ALH TC
TA
-40
-40 -
-100
85 ºC
°C
Storage Temperature All TSTG -55 -125 ºC
Operating Humidity All - - - 85 %
I/O Isolation
(Conditions : 50µA for 5 sec,
slew rate of 1500V/10sec)
Input-Output
Input-Case
Output-Case
All
AEH
AEH
-
-
-
-
-
-
-
-
-
1500
1500
1500
Vdc
Vdc
Vdc
Output Power 3.3V PO,max - - 198 W
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 4 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Electrical Specifications (continued)
INPUT SPECIFICATIONS
Parameter Device Symbol Min Typ Max Unit
Operating Input Voltage All VIN 36 48 75 VDC
Maximum Input Current1
(VIN = 0 to VIN,max: IO = IO,max)F (3.3V) IIN,max - - 7.2 A
Input Reflected-ripple Current 2
(5Hz to 20MHz: 12uH source
impedance: TA = 25 ºC.)
All II- - 15 mAPK-PK
No Load Input Power
(VIN = VIN,nom ) All ---5W
Note: 1. The power module is not internally fused. An input line fuse must always be used.
2. See Figure 1 for the Input Reflected-Ripple Current Test Setup.
OUTPUT SPECIFICATIONS
Parameter Device Symbol Min Typ Max Unit
Output Voltage Setpoint
(VIN = VIN,min to VIN,max at
IO = IO,max ; TA = 25 ºC )
3.3V VO,SET 3.24 3.3 3.34 Vdc
Output Regulation:
Line
Load (IO = IO,min to IO,max)
Temp (AEH: -40 ºC to 100ºC)
(ALH: -40°C to 85°C)
All
All
All
-
-
-
-
-
-
0.1
0.1
-
0.4
0.4
1.0
%
%
%Vo
Output Ripple and Noise3
Peak-to-Peak (5 Hz to 20 MHz)
VIN = 36V, 48V
VIN = 75V 3.3V -
--
-66
-100
150 mVPK-PK
mVPK-PK
External Load Capacitance
(See Stability Curves for Detail) All - - - 50,000 µF
Rated Output Current All Io 0-60 A
Output Current-limit Inception
(when unit is shut down) All Io 63 -77 A
Efficiency4
(VI = VIN,nom ; IO,max ; TA = 25°C) 3.3V -90 91 -%
Switching Frequency All -180 195 210 KHz
Note: 3. See Figure 2 for the Output Ripple Test Setup
4. Refer to Figures 5 and 6 for the Efficiency Curves
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 5 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Electrical Specifications (continued)
OUTPUT SPECIFICATIONS
Parameter Device Symbol Min Typ Max Unit
Dynamic Response5 :
(∆IO/∆t = 1A/10µs ; VI = VIN,nom ;
TA = 25°C)
Load Change from IO = 50% to
75% of IO,max :
Peak Deviation Settling Time (to
VO,nom)
All -
-
-
-
-
-
150
300
mV
µsec
Load Change from IO = 50% to
25% of IO,max :
Peak Deviation Settling Time (to
VO,nom)
All -
-
-
-
-
-
150
300
mV
µsec
Turn-On Time
(IO = IO,max ; Vo within 1%) All - - 4 10 msec
Output Voltage Overshoot
(IO = IO,max ; TA = 25°C) All - - 0 4 %Vo
Note: 5. Refer to the Transient characteristics on Figures 7 and 8.
FEATURE SPECIFICATIONS
Parameter Device Symbol Min Typ Max Unit
Enable Pin Voltage :
Logic Low
Logic High All
All -0.7
2.95 -
-1.2
10 V
V
Enable Pin Current :
Logic Low
Logic High (ILEAKAGE at 10V) All
All -
--
-1.0
50 mA
µA
Module Output Voltage @ Logic Hi AEH/ALH60x48N - - 0.2 V
Module Output voltage @ Logic Low AEH/ALH60X48 - - 0.2 V
Output Voltage Adjustment Range6All -90 -110 %Vo
Output Overvoltage Clamp 3.3V VO,CLAMP 3.90 4.10 5.00 V
Undervoltage Lockout
Turn-on Point
Turn-off Point All
All -
-34.0
33.0 34.8
33.5 35.5
34.5 V
V
Isolation Capacitance All - - 2700 -PF
Isolation Resistance All -10 - - MΩ
Calculated MTBF
(IO = IO,max ; TA = 25°C) All - - TBD -Hours
Note: 6. For Output Voltage Adjustment setup, refer to Figures 3 and 4.
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 6 OF 21
SEPTEMBER 26, 2002 - REVISION 02
SAFETY APPROVAL
The series have been certified through:
• UL, cUL 60950 (Recognized)
• EN 60950 through TUV- PS
Figure 1. Input Reflected -Ripple Test Setup
Figure 2. Peak to Peak Output Noise and Ripple Test Measurement Setup
BATTERY Cs 220 uF
ESR < 0.1 OHM
@ 20 ºC, 100 kHz
Ltest
12 uH
33 uF
ESR < 0.7 OHM
@ 20 ºC, 100 kHz
Vi(+)
Vi(-)
TO OSCILLOSCOPE
Note: Measure the input reflected-ripple current with a simulated source inductance
(LTEST) of 12uH. Capacitor CS offsets possible battery impedance. Measure
current as shown above.
Vo(+)
Vo(-)
RESISTIVE
LOAD
10 uF0.1 uF SCOPE
COPPER STRIP
Note: Use a 0.1µF @50V X7R ceramic capacitor and a 10µF @ 25V tantalum
capacitor. Scope measurement should be made using a BNC socket.
Position the load between 51 mm and 76 mm (2 in. and 3 in.) from module.
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 7 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Basic Operation and Features
AEH60 / ALH60 converters were designed specifically to address applications where ultra high power density is required.
These modules provide basic insulation and 1500V isolation with very high output current capability in an industry
standard half size module. Operating from 36 to 75V input, they have standard features such as remote sense, trim, OVP,
OCP and OTP. AEH60 series devices will accept industry standard heat sinks to enhance thermal performance in
applications with conductive cooling.
Remote Sense (+Sense, -Sense)
Connect the + Sense and – Sense pins close to the load to allow the module to compensate for the voltage drop across
conductors carrying high load current. If remote sense is not required (for example if the load is close to the module) the
sense pins should be connected to the corresponding output pins. Maximum voltage drop compensation is 10% Vout. It is
important to avoid introducing lumped inductance or capacitance into the remote path. Do not connect remote sense lines
“beyond” any external output filter stages used with the module.
Trim Function
Output voltage adjustment is accomplished by connecting an external resistor between the Trim Pin and either the +Sense
or –Sense Pins.
To adjust Vo to a higher value, please refer to Figure 3.
An external resistor, Radj_up should be connected
between the Trim Pin and the +Sense Pin. From Equation
(1), Radj_up resistor can be determined for the required
output voltage increment.
Equation (1)
where: Radj_up - in kΩ
%Vo, adj - percent change in output voltage
To adjust Vo to a lower value, please refer to Figure 4.
An external resistor, Radj_down should be connected
between the Trim Pin and the -Sense Pin. From Equation
(2), Radj_down resistor can be determined for the
required output voltage change.
Equation (2)
where: Radj_down - in kΩ
%Vo, adj - percent change in output voltage
Figure 3. Radj_up Setup to increase Output Voltage
Figure 4. Radj_down Setup to decrease Output Voltage
Radj_up =
Vo*(100 + %Vo,adj)
1.225*%Vo,adj
100+ 2%Vo,adj
%Vo,adj kohm
Radj_down
.
100
, %Vo adj 2 kohm
Technical Reference Notes
Hercules (AEH/ALH60) Open
Frame or HS Adapted
MODEL: AEH/ALH60F48 SHEET 8 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Basic Operation and Features (continued)
Output Over Voltage Protection
The output over voltage system consists of a separate control loop, independent of the primary feedback path. This control
loop has a higher voltage set point than the main circuit. In a fault condition, the converter latches which ensures that the
output voltage does not exceed VO,CLAMP,max. The converter will operate back normally once the fault is removed and the
input voltage is cycled or the enable pin is toggled.
Output Over Current Protection
To provide protection in an output overload or short circuit condition, the converter is equipped with current limiting
circuitry and can endure fault conditions for an unlimited duration. At the point of current-limit inception, the converter
latches, causing the output current to be limited both in peak and duration. The converter will operate back normally once
the overload/ fault is removed and the input voltage is cycled or the enable pin is toggled.
Enable Function
Two enable options are available. Positive Logic Enable (no suffix required in part number) and Negative Logic Enable
(suffix “N”). Positive Logic Enable turns the converter on during a logic-high voltage on the enable pin, and off during a
logic-low. Negative Logic Enable turns the converter off during a logic-high and on during a logic-low.
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 9 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Performance Curves
EFFICIENCY
Figure 5. AEH/ALH60 3V3 Efficiency Curve at TC = 25°CFigure 6. AEH/ALH60 3V3 Efficiency Curve at TC = 70°C
TRANSIENT RESPONSE
3V3 Efficiency VS Load Current @ Tc = 25 deg C
55%
60%
65%
70%
75%
80%
85%
90%
95%
010 20 30 40 50 60
LOAD CURRENT [Amp]
EFFICIENCY [%]
Vin = 36Vdc
Vin = 48Vdc
Vin = 75Vdc
3V3 Efficiency VS Load Current @ Tc = 70 deg C
55%
60%
65%
70%
75%
80%
85%
90%
95%
010 20 30 40 50 60
LOAD CURRENT [Amp]
Vin = 36Vdc
Vin = 48Vdc
Vin = 75Vdc
Figure 7. 3V3 output: 50% to 75% load change with no
external capacitor at 0.1A/uS slew rate (CH1 at
1A/10mV).
Figure 8: 3V3 output: 50% to 75% load change with
10,000uF external capacitor at 0.1A/uS slew
rate (CH1 at 1A/10mV).
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 10 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Performance Curves (continued)
CURRENT VS TEMPERATURE CURVES
Figure 9. Load Current VS. Temperature (Open Frame)
Figure 10. Load Current VS. Temperature (Baseplate)
3V3 ALH (Open Frame) Load Current VS. Temperature
0
10
20
30
40
50
60
25 30 35 40 45 50 55 60 65 70 75 80 85
AMBIENT TEMPERATURE (ºC)
LOAD CURRENT[Amp]
Nat. Conv.
0.5 m/s (100 ft/min)
1.0 m/s (200 ft/min)
2.0 m/s (400 ft/min)
3V3 AEH (baseplate) Load Current VS. Temperature
0
10
20
30
40
50
60
25 30 35 40 45 50 55 60 65 70 75 80 85
AMBIENT TEMPERATURE (ºC)
LOAD CURRENT [Amp]
Nat. Conv.
0.5 m/s (100 ft/min)
1.0 m/s (200 ft/min)
2.0 m/s (400 ft/min)
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 11 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Performance Curves (continued)
STARTUP CHARACTERISTICS
Figure 11. AEH60F48 (3.3V): O/P startup characteristic
with no external capacitor at Vin = 48V / 20A
resistive load
Figure 12. AEH60F48 (3.3V): O/P startup characteristic
with 9400 uF external capacitor at Vin = 48V /
20A resistive load.
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 12 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Input Filter for FCC Class B Conducted Noise
A reference design for an input filter that can provide FCC Class B conducted noise levels is shown below (See Figure 13).
Two common mode connected inductors are used in the circuit along with balanced bypass capacitors to shunt common
mode currents into the ground plane. Shunting noise current back to the converter reduces the amount of energy reaching
the input LISN for measurement.
The application circuit shown has an earth ground (frame ground) connected to the converter output (-) terminal. Such a
configuration is common practice to accommodate safety agency requirements. Grounding an output terminal results in
much higher conducted emissions as measured at the input LISN because a hard path for common mode current back to the
LISN is created by the frame ground. “Floating” loads generally result in much lower measured emissions. The electrical
equivalent of a floating load, for EMI measurement purposes, can be created by grounding the converter output (load)
through a suitably sized inductor(s) while maintaining the necessary safety bonding.
Also shown is a sketch of a PCB layout used to achieve Class B conducted noise levels (See Figure 14). It is important to
avoid extending the ground plane or any other conductors under the inductors (particularly L2) because capacitive coupling
to that track or plane can effectively bypass the inductor and degrade high frequency performance of the filter.
PARTS LIST
CIRCUIT CODE DESCRIPTION
L1, L2 Pulse Engineering P0353 / 590uH
C1, C3, C4, C5, C6, C11, C12 0.01uF / 2000V
C2, C7, C9 100uF / 100V Aluminum
C13, C14 470pF / 100V Ceramic
C8, C10 2.2uF / 100V Film
Figure 13: Class B Filter Circuit
C1 C2
C5
C6
C7 C8
C14
C13
C9
L1A
L1B
L2A
L2B
C10
C12
+ +
+ Vin
- Vin
CONVERTER
+
48 VDC
INPUT
-
+
C11
+ Vout
- Vout
C4
C3
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 13 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Input Filter for FCC Class B Conducted Noise (continued)
Figure 14: Recommended PCB Layout for Class B Filter
Figure 15: AEH60F48 and ALH60F48 Noise Spectrum
Input Noise Spectrum
0
10
20
30
40
50
60
70
80
90
2.E+04 5.E+04 1.E+05 3.E+05 7.E+05 2.E+06 4.E+06 9.E+06 2.E+07
Frequency (Hz)
LISN Voltage db/uv
FCC Part 15 & CISPR 22 A & B Limits - conducted noise
AVERAGE
LIMITS
- Vin
+ Vin
C2C1 C7
C5
C6
C12
C9 C10C8
GND PLANE
GND PLANE
C
O
N
V
E
R
T
E
R
1 1
2 2
3
4
3
4
TOP
VIEW
+48 VDC
48 V Return
L1
A / B L2
A / B
C3
C4
C11
C13
C14
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 14 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Thermal Considerations
While the ALH60 (Open Frame Converter) is designed to provide the maximum performance at the lowest profile, the
AEH60 (Power Converter with HS adapter) operates in a variety of thermal environments. Sufficient cooling should be
provided to help ensure reliable operation of either device. Heat generating components are thermally coupled to the
adapter where heat energy is removed by conduction, convection, and radiation to the surrounding environment. Heat sinks
can provide enhanced output performance as shown below. Proper cooling can be verified by measuring the case
temperature (Center of adapter plate/baseplate).
HEAT TRANSFER CHARACTERISTICS
Increasing airflow over the converter enhances heat transfer via convection. Figure 16 shows worse case maximum power
that can be dissipated by the converter, without exceeding the maximum adapter plate temperature, versus local ambient
temperature (TA) for natural convection through 2.0 m/s (400 ft/min). Figure 17 shows actual maximum power that can be
dissipated through both the adapter plate and through the output pins (unit soldered into a 4” square copper plane (2 Oz.) or
equivalent).
Figure 16. Forced Convection Power Dissipation
Note: This is worse case dissipation - additional Heat transfer through O/P pins will increase
allowable dissipation considerably. See Figure 17.
AEH60 Series
Power Dissipation vs Temp
Forced Convection without HS
0
5
10
15
20
25
30
25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Ambient Temperature (ºC)
Power Dissipation (Watts)
Nat. Conv.
1.0 m/s (200 ft/min)
1.5 m/s (300 ft/min)
2.0 m/s (400 ft/min)
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 15 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Thermal Considerations (continued)
Figure 17. Actual Measured Forced Convection Power Dissipation
Note: This is an actual measured maximum dissipation with heat transfer through output pins
included.
Figure 18. ALH/AEH60F48 Power Dissipation VS. Load Current.
AEH60 Series
Actual Power Dissipation vs Temp
Forced Convection without HS
0
5
10
15
20
25
30
25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Ambient Temperature (ºC)
Power Dissipation [W]
Nat. Conv.
1.0 m/s (200 ft/min)
1.5 m/s (300 ft/min)
2.0 m/s (400 ft/min)
Power Dissipation vs Output Current
Tc = 25 Deg Celsius
0.0
5.0
10.0
15.0
20.0
25.0
010 20 30 40 50 60
Output Current [Amps]
Power Dissipation [W]
Vin = 36 Vdc
Vin = 48 Vdc
Vin = 75 Vdc
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 16 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Thermal Considerations (continued)
HEATSINK SELECTION ILLUSTRATED
Figure 19 shows Case-to-Ambient Thermal Resistance, θ (°C/W), for AEH / ALH60 modules. These curves can be used
to predict which heat sink will be needed for a particular environment. As an illustration, let's refer to below application
requirement:
An application requires 45 Amps of 3.3V in a 55°C environment with airflow of 1.0 m/s (200 ft/min); the
minimum heat sink required can be determined through Equation (3).
Equation (3) θ ≤ (TC, MAX – TA) / PD
where: θ=Module’s Total Thermal Resistance
TC, MAX =Case Temperature (100 °C)
TA=Ambient Temperature (55 °C)
PD=Power Dissipation (15W)
From Figure 18, the power dissipation for a 45A-load requirement can be determined (PD = 15W). Through Equation (3),
the Thermal Resistance can be calculated to be at θθ ≤≤ 3.0 °°C/W.
Based on Figure 19, the ¼" HS (heatsink), or greater, will be able to handle the required 45A-load at 55 °C environment
and with 1.0 m/s (200 ft/min) airflow.
Figure 19. Case-to-Ambient Thermal Resistance vs. Air Velocity
AEH60 Series
Case to Ambient Thermal
Resistance Curves
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600
Airflow [ ft / min]
Thermal Resistance RCA (OC/W)
No HS
1/4" HS
1/2" HS
1" HS
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 17 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Stability: Figures 20 and 21 are plots of internal Module Loop Gain and Phase Shift vs Frequency. Curves for typical
resistive and reactive loads are shown. System stability (Phase and Gain Margins) when the module is connected to other
loads can be determined from the Young's Stability Curves on Figures 23 and 24. Figure 22 shows an operating zone in
which phase margin can be determined for virtually any load resistance and shunt capacitance. See Ref. 1 for application of
curves.
Figure 20. Loop Gain VS. Frequency at 0.171Ω load with
no output capacitance, Figure 21. Phase Shift VS. Frequency at 0.171Ω load
with 9400uF cap load (3.9mΩ ESR)
Figure 22: Phase Margin vs Load Resistance
100 1.1031.1041.105
40
30
20
10
0
10
20
30
40
50
60 LOOP GAIN vs FREQUENCY
FREQUENCY Hz
GAIN db
100 1.1031.1041.105
50
0
50
100
150
200 LOOP PHASE SHIFT vs FREQUENCY
FREQUENCY Hz
PHASE SHIFT deg
0.01 0.1 1
50
60
70
80
90
100 PHASE MARGIN vs LOAD RES
LOAD RESISTANCE ohms
PHASE MARGIN deg
9.4K uF,
3.9 mohms
No Output
Capacitance
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 18 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Young’s Stability Curves
PHASE MARGIN
Figure 23. Young’s Stability Curve – Phase Margin
100 1.1031.1041.105
1.10 3
0.01
0.1
1YSC IMPEDANCE MAGNITUDE in OHMS
Impedance Magnitude ( Ohms )
100 1.1031.1041.105
150
100
50
0
50
Frequency
Impedance Phase Angle ( Degrees )
_______15°
_______30°
_______45°
_______60°
_______75°
_______90°
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 19 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Young’s Stability Curves
GAIN MARGIN
Figure 24. Young’s Stability Curve – Gain Margin
100 1 .10 31.10 41.10 5
1.10 6
1.10 5
1.10 4
1.10 3
0.01
0.1
1YSC GAIN MARGIN
gain
100 1 .10 31.10 41.10 5
200
150
100
50
0
50
Frequency
Phase
______10db
______20db
______30db
______40db
______50db
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 20 OF 21
SEPTEMBER 26, 2002 - REVISION 02
Mechanical Specifications
Parameter Device Symbol Min Typ Max Unit
Dimension AEH/ALH L-2.40 [60.96] -in [mm]
AEH/ALH W-2.30 [58.42] -in [mm]
AEH H-0.50 [12.70] -in [mm]
ALH H-0.40 [10.16] -in [mm]
Weight AEH -130 [4.60] -g [oz]
ALH -110 [3.90] -g [oz]
PIN ASSIGNMENT
1+ VIN 6- Sense
2Enable ON/OFF 7Trim
3Case (AEH version) 8+ Sense
4- VIN 9+ Output
5- Output
Note: Nominal diameter for Pins 5 & 9 = 0.08", remaining pins at 0.04"
OUTLINE DRAWING
Figure 25. AEH60 - baseplate outline drawing (bottom view)
Technical Reference Notes (AEH60/ALH60F48)
MODEL: AEH/ALH60F48 SHEET 21 OF 21
SEPTEMBER 26, 2002 - REVISION 02
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Mechanical Specifications (continued)
OUTLINE DRAWING
Figure 26. ALH60 - open-frame outline drawing (bottom view)
SOLDERING CONSIDERATIONS
The AEH/ALH 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.
PART NUMBER CODING SCHEME FOR ORDERING
AxH60 y48 z
xConstruction
E: Enhanced thermals; Heatsink adapted
L: Low profile; Open Frame
yOutput Voltage
F = 3.3V Y = 1.8V
G = 2.5V K = 1.2V
zOption
N : Negative Enable
No Suffix : Positive Enable