LAMBDA ADVANCED ANALOG INC. λλ
AHE281XD Series
Dual Output, Hybrid - High Reliability
DC/DC Converter
DESCRIPTION FEATURES
The AHE Series of DC/DC converters feature high
power density and an extended temperature range
for use in military and industrial applications.
Designed to MIL-STD-704 input requirements, these
devices have nominal 28VDC inputs with ±12V and
±15V dual outputs to satisfy a wide range of
requirements. The circuit design incorporates a
pulse width modulated push-pull topology operating
in the feed-forward mode at a nominal switching
frequency of 250KHz. Input to output isolation is
achieved through the use of transformers in the
forward and feedback circuits.
The advanced feedback design provides fast loop
response for superior line and load transient
characteristics and offers greater reliability and
radiation tolerance than devices incorporating
optical feedback circuits.
Manufactured in a facility fully qualified to MIL-PRF-
38534, these converters are available in four
screening grades to satisfy a wide range of
requirements. The CH grade is fully compliant to
the requirements of MIL-PRF-38534 for class H.
The HB grade is processed and screened to the
class H requirement, but may not necessarily meet
all of the other MIL-PRF-38534 requirements, e.g.,
element evaluation and Periodic Inspection (P.I.)
not required. Both grades are tested to meet the
complete group "A" test specification over the full
military temperature range without output power
deration. Two grades with more limited screening
are also available for use in less demanding
applications. Variations in electrical, mechanical
and screening can be accommodated. Contact
Lambda Advanced Analog for special requirements.
nn 17 To 40 Volt Input Range (28VDC Nominal)
nn ±± 12 and ±± 15 Volt Outputs Available
nn Indefinite Short Circuit and Overload
Protection
nn 12.9W/in3 Power Density
nn 15 Watts Output Power
nn Fast Loop Response For Superior Transient
Characteristics
nn Operating Temperature Range From -55°C to
+125°C Available
nn Popular Industry Standard Pin-Out
nn Resistance Seam Welded Case For Superior
Long Term Hermeticity
nn Efficiencies Up to 82%
nn Shutdown From External Signal
nn Military Screening
nn 314,000 Hour MTBF at 85°C, AUC
2
SPECIFICATIONS AHE2812D
ABSOLUTE MAXIMUM RATINGS
Input Voltage -0.5V to 50V
Soldering Temperature 300°C for 10 seconds
Case Temperature Operating-55°C to +125°C
Storage -65°C to +135°C
TABLE I. Electrical Performance Characteristics
Test Symbol Conditions
-55°C ≤ TC ≤ +125°C
VIN = 28 V dc ±5%, CL = 0 unless
otherwise specified
Group A
subgroups Device
types Limits Unit
Min Max
Output voltage VOUT IOUT = 0 1All ±11.88 ±12.12 V
2,3 ±11.76 ±12.24
Output current 9/ 11/IOUT VIN = 17, 28, and 40 V dc 1,2,3 All 0.0 ±625 mA
Output ripple voltage 8/ 9/VRIP VIN = 17, 28, and 40 V dc
B.W. = dc to 2 mHz 1,2,3 All 60 mV p-p
Output power 4/ 9/ 11/POUT VIN = 17, 28, and 40 V dc 1,2,3 All 15 W
Line 9/
regulation 10/VRLINE VIN = 17, 28, and 40 V dc
IOUT = 0, ±313, and ±625 mA 1All 30 mV
2,3 60
Load
regulation 9/VRLOAD VIN = 17, 28, and 40 V dc
IOUT = 0, ±313, and ±625 mA 1,2,3 All 120 mV
Input current IIN IOUT = 0, inhibit (pin 2) tied to input
return (pin 10) 1,2,3 All 18 mA
IOUT = 0,
inhibit (pin 2) = open 40
Input ripple current 8/IRIP IOUT = ±625 mA
B.W. = dc to 2 MHz 1,2,3 All 50 mA p-p
Efficiency EFF IOUT = ±625 mA,
TC = +25°C1All 80 %
Isolation ISO Input to output or any pin
to case (except pin 8) at 500 V dc, TC =
+25°C
1All 100 MΩ
Capacitive load 6/ 12/CLNo effect on dc performance,
TC = +25°C4All 200 µF
Power dissipation
load fault PDOverload, TC = +25°C 3/1All 6W
Short circuit, TC = +25°C6
See footnotes at end of table
3
AHE2812D
TABLE I. Electrical Performance Characteristics - Continued
Test Symbol Conditions
-55°C ≤ TC ≤ +125°C
VIN = 28 V dc ±5%, CL = 0 unless
otherwise specified
Group A
Subgroups Device
Type Limits Unit
Min Max
Switching 9/
frequency FSIOUT = ±625 mA 4,5,6 01 225 275 KHz
02 225 245
03 250 275
Output response to step transient
load changes 7/VOTLOAD 50 percent load to/from 100 percent load 4All -300 +300 mV pk
5,6 -450 +450
No load to/from 50 percent load 4All -500 +500
5,6 -750 +750
Recovery time step transient load
changes 1/ 7/TTLOAD 50 percent load to/from 100 percent load 4All 70 µs
5,6 100
No load to 50 percent load 4,5,6 All 1500
50 percent load to no load 4,5,6 All 5ms
Output response to transient step
line changes 5/ 12/VOTLINE Input step 17 TO 40 V dc 4,5,6 All 1200 mV pk
Input step 40 TO 17 V dc 4,5,6 All -1500
Recovery time transient step
line changes 1/ 5/ 12/TTLINE Input step 17 TO 40 V dc 4,5,6 All 4ms
Input step 40 TO 17 V dc 4,5,6 All 4
Turn on overshoot 9/VTonOS IOUT = 0 and ±625 mA 4,5,6 All 600 mV pk
Turn on delay 2/ 9/TonDIOUT = 0 and ±625 mA 4,5,6 All 10 ms
Load fault recovery 12/TrLF 4,5,6 All 10 ms
Notes:
1/ Recovery time is measured from the initiation of the transient to where VOUT has returned to within ±1 percent of VOUT at 50 percent load.
2/ Turn on delay time measurement is for either a step application of power at the input or the removal of a ground signal from the inhibit pin (pin 2) while power is applied to the
input.
3/ An overload is that condition with a load in excess of the rated load but less than that necessary to trigger the short circuit protection and is the condition of maximum
power dissipation.
4/ Total power at both outputs. For operation at 16 V dc input, derate output power by 33 percent.
5/ Input step transition time between 2 and 10 microseconds.
6/ Capacitive load may be any value from 0 to the maximum limit without compromising dc performance. A capacitive load in excess of the maximum limit will not
disturb loop stability but may interfere with the operation of the load fault detection circuitry, appearing as a short circuit during turn on.
7/ Load step transition time between 2 and 10 microseconds.
8/ Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
9/ Tested at each output.
10/ When operating with unbalanced loads, at least 25 percent of the load must be on the positive output to maintain regulation.
11/ Parameter guaranteed by line and load regulation tests.
12/ Parameter shall be tested as part of design characterization and after design or process changes. Thereafter parameters shall be guaranteed to the limits specified in Table I.
4
SPECIFICATIONS AHE2815D
ABSOLUTE MAXIMUM RATINGS
Input Voltage -0.5V to 50V
Soldering Temperature 300°C for 10 seconds
Case Temperature Operating-55°C to +125°C
Storage -65°C to +135°C
TABLE II. Electrical Performance Characteristics
Test Symbol Conditions
-55°C ≤ TC ≤ +125°C
VIN = 28 V dc ±5%, CL = 0 unless
otherwise specified
Group A
subgroups Device
types Limits Unit
Min Max
Output voltage VOUT IOUT = 0 1All ±14.85 ±15.15 V
2,3 ±14.70 ±15.30
Output current 9/
11/IOUT VIN = 17, 28, and 40 V dc 1,2,3 All 0.0 ±500 mA
Output ripple 8/
voltage 9/VRIP VIN = 17, 28, and 40 V dc
B.W. = dc to 2 mHz 1,2,3 All 60 mV p-p
Output power 4/ 9/ 11/POUT VIN = 17, 28, and 40 V dc 1,2,3 All 15 W
Line 9/
regulation 10/VRLINE VIN = 17, 28, and 40 V dc
IOUT = 0, ±250, and ±500 mA 1All 35 mV
2,3 75
Load
regulation 9/VRLOAD VIN = 17, 28, and 40 V dc
IOUT = 0, ±250, and ±500 mA 1,2,3 All 150 mV
Input current IIN IOUT = 0, inhibit (pin 2) tied to input return
(pin 10) 1,2,3 All 18 ma
IOUT = 0,
inhibit (pin 2) = open 40
Input ripple 8/
current IRIP IOUT = ±500 mA
B.W. = dc to 2 MHz 1,2,3 All 50 mA p-p
Efficiency EFF IOUT = ±500 mA,
TC = +25°C1All 80 %
Isolation ISO Input to output or any pin
to case (except pin 8) at 500 V dc, TC =
+25°C
1All 100 MΩ
Capacitive load 6/ 12/CLNo effect on dc performance,
TC = +25°C4All 200 µF
Power dissipation
load fault PDOverload, TC = +25°C 3/1All 6W
5
AHE2815D
TABLE II. Electrical Performance Characteristics - Continued.
Test Symbol Conditions
-55°C ≤ TC ≤ +125°C
VIN = 28 V dc ±5%, CL = 0 unless
otherwise specified
Group A
Subgroups Device
Type Limits Unit
Min Max
Switching 9/
frequency FSIOUT = ±500 mA 4,5,6 01 225 275 KHz
02 225 245
03 250 275
Output response to step transient
load changes 7/VOTLOAD 50 percent load to/from 100 percent load 4All -300 +300 mV pk
5,6 -450 +450
No load to/from 50 percent load 4All -500 +500
5,6 -750 +750
Recovery time step transient load
changes transient load changes 1/ 7/TTLOAD 50 percent load to/from 100 percent load 4All 70 µs
5,6 100
No load to 50 percent load 4,5,6 All 1500
50 percent load to no load 4,5,6 All 5ms
Output response to transient step line
changes 5/ 12/VOTLINE Input step 17 to 40 V dc 4,5,6 All 1500 mV pk
Input step 40 to 17 V dc 4,5,6 All -1500
Recovery time transient step line
changes 1/ 5/ 12/TTLINE Input step 17 to 40 V dc 4,5,6 All 4ms
Input step 40 to 17 V dc 4,5,6 All 4
Turn on overshoot 9/VTonOS IOUT = 0 and ±500 mA 4,5,6 All 600 mV pk
Turn on delay 2/ 9/TonDIOUT = 0 and ±500 mA 4,5,6 All 10 ms
Load fault recovery 12/TrLF 4,5,6 All 10 ms
Notes:
1/ Recovery time is measured from the initiation of the transient to where VOUT has returned to within ±1 percent of VOUT at 50 percent load.
2/ Turn on delay time measurement is for either a step application of power at the input or the removal of a ground signal from the inhibit pin (pin 2) while power is applied to the input.
3/ An overload is that condition with a load in excess of the rated load but less than that necessary to trigger the short circuit protection and is the condition of maximum power dissipation.
4/ Total power at both outputs. For operation at 16 V dc input, derate output power by 33 percent.
5/ Input step transition time between 2 and 10 microseconds.
6/ Capacitive load may be any value from 0 to the maximum limit without compromising dc performance. A capacitive load in excess of the maximum limit will not disturb loop stability but may
interfere with the operation of the load fault detection circuitry, appearing as a short circuit during turn on.
7/ Load step transition time between 2 and 10 microseconds.
8/ Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
9/ Tested at each output.
10/ When operating with unbalanced loads, at least 25 percent of the load must be on the positive output to maintain regulation.
11/ Parameter guaranteed by line and load regulation tests.
12/ Parameter shall be tested as part of design characterization and after design or process changes. Thereafter parameters shall be guaranteed to the limits specified in Table II.
BLOCK DIAGRAM (Single Output)
designer must assign one of the converters as the
master. Then, by definition, the remaining
converters become slaves and will operate at the
masters' switching frequency. The user should
be aware that the synchronozation system is fail-safe;
that is, the slaves will continue operating should the
master frequency be interrupted for any reason.
The layout must be such that the synchronozation
output (Pin 9) of the master device is connected to
the synchronozation input (Pin 9) of each slave
device. It is advisable to keep this run short to
minimize the possibilty of radiating the 250KHz
switching frequency.
The appropriate parts must be ordered to utilize
this feature. After selecting the converters
required for the system, an ‘MSTR’ suffix is
added for the master converter part number and
an ‘SLV’ suffix is added for slave part number.
APPLICATION INFORMATION
Inhibit Function
Connecting the inhibit input (Pin 2) to input
common (Pin 10) will cause the converter to shut
down. It is recommended that the inhibit pin be
driven by an open collector device capable of
sinking at least 400µA of current. The open circuit
voltage of the inhibit input is 11.5 +1 VDC.
EMI Filter
An optional EMI filter (AFC461) will reduce the
input ripple current to levels below the limits
imposed by MIL-STD-461 CEO3.
Device Synchronization
Whenever multiple DC/DC converters are utilized
in a single system, significant low frequency noise
may be generated due to slight difference in the
switching frequencies of the converters (beat
frequency noise). Because of the low frequency
nature of this noise (typically less than 10 KHz), it
is difficult to filter out and may interfere with
proper operation of sensitive systems (communi-
cations, radar or telemetry). Lambda Advanced
Analog offers an option which provides synchroniza-
tion of multiple AHE/ATW converters, thus eliminat-
ing this type of noise.
To take advantage of this capability, the system
INPUT
FILTER
CONTROLLER
1
2
9
10
OUTPUT
FILTER
REGULATOR
& OUTPUT
FILTER
ERROR
AMP
& REF
3
5
4
6
PIN DESIGNATION
AHE2812D
AHE2815D
Pin 1Positive input Pin 10Input common
Pin 2Inhibit input Pin 9 N/C or sync.
Pin 3Positive output Pin 8 Case ground
Pin 4Output common Pin 7 N/C
Pin 5Negative output Pin 6 N/C
PART NUMBER
AHF 28 xx D x / x - xxx
Model Synchronization Option
Input Voltage MSTR—Master
SLV—Slave
Output Voltage
12–12 VDC Temperature Range
15–15 VDC Omit for -55°C to +85°C
ES— -55°C to +105°C
Dual Output HB— -55°C to +125°C
Package Option
F—Flange
Omit for standard
7
HB Screening Process
Per MIL-PRF-38534
Test Inspection Method Conditlon
Pre-Seal Internal Visual 2017
Stabilization Bake 1008 C
Temperature Cycling 1010 C
Constant Acceleration 2001 A, Y1 direction
Burn-in 1015 TC = +125°C
Final Electrical Test Tc = -55,+25,+125°C
Gross Leak 1014 C
Fine Leak 1014 A
External Visual 2009
ES Screening Process
Same as HB screening except as follows:
Test Inspection Method
Constant Acceleration 2001, 500g’s
Burn-in 1015, 96hrs.
Final Electrical 25°C only
FILTER
AHE2805S/ES-MSTR
MASTER
AHE2815D/ES-SLV
SLAVE
AHE2812S/ES-SLV
SLAVE
1
10
1
10
1
10
5
4
3
4
5
5
4
+5V
COMM
+15V
COMM
-15V
+12V
COMM
SYSTEM
BUS
Typical Synchronization Connection Diagram
MECHANICAL OUTLINE
Pin 1
.090R max.
.090R max.
1.120 max.
(28.194)
0.040D x 0.260L
(1.016) (6.604)
0.800
(20.320)
2.120 max.
(53.594)
0.495 max.
(12.573)
4 x 0.400 = 1.600
(10.160) (40.640)
2.880 max.
(73.152)
Pin 1
1.110
(28.194)
2.550±.010
(64.770)
0.800
(20.320)
2.120 max.
(53.594)
0.495 max.
(12.573)
4 x 0.400 = 1.600
(10.160) (40.640) 0.040D x 0.260L
(1.016) (6.604)
.090R max.
0.162D 2 places
(4.115)
Input
Common
N/C or
synchronization
Case
Ground
Pos. Input
Inhibit
Input
Pos. Output
Output
Common
Neg. Output
10 1
65
Bottom
View
Weight
Standard—55 grams max.
Flange—58 grams max.
8
MIL-PRF-38534 Certified
ISO9001 Rgstrd
2270 Martin Avenue
Santa Clara CA 95050-2781
(408) 988-4930 FAX (408) 988-2702
STANDARDIZED MILITARY DRAWING
CROSS REFERENCE
Standardized Vendor Vendor
military drawing CAGE similar
PIN number PIN
5962-9157501HXX 52467 AHE2815D/CH
5962-9157501HZX 52467 AHE2815DF/CH
5962-9157502HXX 52467 AHE2815D/CH-SLV
5962-9157502HZX 52467 AHE2815DF/CH-SLV
5962-9157503HXX 52467 AHE2815D/CH-MSTR
5962-9157503HZX 52467 AHE2815DF/CH-MSTR
Standardized Vendor Vendor
military drawing CAGE similar
PIN number PIN
5962-9204001HXX 52467 AHE2812D/CH
5962-9204001HZX 52467 AHE2812DF/CH
5962-9204002HXX 52467 AHE2812D/CH-SLV
5962-9204002HZX 52467 AHE2812DF/CH-SLV
5962-9204003HXX 52467 AHE2812D/CH-MSTR
5962-9204003HZX 52467 AHE2812DF/CH-MSTR
9849
Output Power (Watts)
Efficiency (%)
Output Power (Watts)
Efficiency (%)
©Lambda Advanced Analog
The information in this data sheet has been carefully checked and is believed to be accurate, however, no
responsibility is assumed for possible errors. The specifications are subject to change without notice.
AHE2815D EFFICIENCY
AHE2812D EFFICIENCY
