LAMBDA ADVANCED ANALOG INC. λλ
ATW2800S Series
Single Output, Hybrid - High Reliability
DC/DC Converter
DESCRIPTION FEATURES
The ATW2800S 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 +5, +12V
and +15V single outputs. The circuit design
incorporates a pulse width modulated push-pull
topology operating in the feed-forward mode at a
nominal switching frequency of 270KHz. 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.
Three standard temperature grades are offered.
Refer to Part Number section. They are provided in
a flanged package for more severe enviroments.
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 19 To 40 Volt Input Range (28VDC Nominal)
nn 30 Watts Output Power
nn Indefinite Short Circuit and Overload
Protection
nn 22.8 W/in3 Power Density
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 83%
nn Shutdown From External Signal
nn Military Screening
nn 250,000 Hour MTBF at 85°C
nn MIL-PRF-38534 Compliant Versions
Available
2
SPECIFICATIONS ATW2805S
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 4.95 5.05 V
2,3 4.90 5.10
Output current 1/IOUT VIN = 19, 28, and 40 V dc 1,2,3 All 0.0 6000 mA
Output ripple voltage 2/VRIP VIN = 19, 28, and 40 V dc
B.W. = dc to 2 MHz 1,2,3 All 50 mV p-p
Output power 1/ 3/POUT VIN = 19, 28, and 40 V dc 1,2,3 All 30 W
Line regulation 4/VRLINE VIN = 19, 28, and 40 V dc
IOUT = 0, 3000, and 6000 mA 1All 5mV
2,3 20
Load regulation 4/VRLOAD VIN = 19, 28, and 40 V dc
IOUT = 0, 3000, and 6000 mA 1,2,3 All 30 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 2/IRIP IOUT = 6000 mA
B.W. = dc to 2 MHz 1,2,3 All 20 mA p-p
Efficiency EFF IOUT = 6000 mA,
TC = +25°C1All 78 %
Isolation ISO Input to output or any pin
to case (except pin 7) at 500 V dc, TC
= +25°C
1All 100 MΩ
Capacitive load 5/ 6/CLNo effect on dc performance,
TC = +25°C4All 500 µF
Power dissipation load fault PDOverload, TC = +25°C 7/1All 12 W
Short circuit, TC = +25°C9
See footnotes at end of table.
3
ATW2805S
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 frequency FS IOUT = 6000 mA 4,5,6 01 250 300 kHz
02 250 270
03 275 300
Output response to step
transient load changes 8/VOTLOAD 4000 mA to/from 6000 mA 4,5,6 All -500 +500 mV pk
500 mA to/from 2500 mA 4,5,6 All -500 +500
Recovery time step transient
load changes 8/ 9/TTLOAD 4000 mA to/from 6000 mA 4 All 100 µs
5,6 200
500 mA to/from 2500 mA 4 All 100
5,6 200
Turn on overshoot VTonOS IOUT = 0 and 6000 mA 4,5,6 All 500 mV pk
Turn on delay 10/TonD IOUT = 0 and 6000 mA 4,5,6 All 12 ms
Load fault recovery 6/ 10/TrLF 4,5,6 All 12 ms
Notes:
1/ Parameter guaranteed by line and load regulation tests.
2/ Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
3/ Above +125°C case, derate output power linearly to 0 at +135°C.
4/ Output voltage measured at load with remote sense leads connected across load.
5/ 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.
6/ 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.
7/ 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.
8/ Load step transition time between 2 and 10 microseconds.
9/ 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.
10/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.
4
SPECIFICATIONS ATW2812S
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 4.95 5.05 V
2,3 4.90 5.10
Output current 1/IOUT VIN = 19, 28, and 40 V dc 1,2,3 All 0.0 6000 mA
Output ripple voltage 2/VRIP VIN = 19, 28, and 40 V dc
B.W. = dc to 2 MHz 1,2,3 All 50 mV p-p
Output power 1/ 3/POUT VIN = 19, 28, and 40 V dc 1,2,3 All 30 W
Line
regulation 4/VRLINE VIN = 19, 28, and 40 V dc
IOUT = 0, 3000, and 6000 mA 1All 5mV
2,3 20
Load
regulation 4/VRLOAD VIN = 19, 28, and 40 V dc
IOUT = 0, 3000, and 6000 mA 1,2,3 All 30 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 2/IRIP IOUT = 6000 mA
B.W. = dc to 2 MHz 1,2,3 All 20 mA p-p
Efficiency EFF IOUT = 6000 mA, TC = +25°C1All 78 %
Isolation ISO Input to output or any pin
to case (except pin 7) at 500 V dc, TC
= +25°C
1All 100 MΩ
Capacitive load 5/ 6/CLNo effect on dc performance,
TC = +25°C4All 500 µF
Power dissipation load fault PDOverload, TC = +25°C 7/1All 12 W
Short circuit, TC = +25°C9
See footnotes at end of table.
5
ATW2812S
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 frequency FS IOUT = 6000 mA 4,5,6 01 250 300 kHz
02 250 270
03 275 300
Output response to step
transient load changes 8/VOTLOAD 4000 mA to/from 6000 mA 4,5,6 All -500 +500 mV pk
500 mA to/from 2500 mA 4,5,6 All -500 +500
Recovery time step transient
load changes 8/ 9/TTLOAD 4000 mA to/from 6000 mA 4 All 100 µs
5,6 200
500 mA to/from 2500 mA 4 All 100
5,6 200
Turn on overshoot VTonOS IOUT = 0 and 6000 mA 4,5,6 All 500 mV pk
Turn on delay 10/TonD IOUT = 0 and 6000 mA 4,5,6 All 12 ms
Load fault recovery 6/ 10/TrLF 4,5,6 All 12 ms
Weight Flange 75 grams
Notes:
1/ Parameter guaranteed by line and load regulation tests.
2/ Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
3/ Above +125°C case, derate output power linearly to 0 at +135°C.
4/ Output voltage measured at load with remote sense leads connected across load.
5/ 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.
6/ 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.
7/ 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.
8/ Load step transition time between 2 and 10 microseconds.
9/ 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.
10/ 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.
6
SPECIFICATIONS ATW2815S
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 III. 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 1/IOUT VIN = 17, 28, and 40 V dc 1,2,3 All 0.0 1333 mA
Output ripple voltage 2/VRIP VIN = 17, 28, and 40 V dc
B.W. = dc to 2 MHz 1,2,3 All 60 mV p-p
Output power 1/ 3/POUT VIN = 17, 28, and 40 V dc 1,2,3 All 20 W
Line
regulation VRLINE VIN = 17, 28, and 40 V dc
IOUT = 0, .677, and 1333 mA 1All 35 mV
2,3 75
Load
regulation VRLOAD VIN = 17, 28, and 40 V dc
IOUT = 0, .677, and 1333 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 35
Input ripple current 2/IRIP IOUT = 1333 mA
B.W. = dc to 2 MHz 1,2,3 All 50 mA p-p
Efficiency EFF IOUT = 1333 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 4/ 5/CLNo effect on dc performance, TC =
+25°C4All 200 µF
Power dissipation load fault PDOverload, TC = +25°C 6/1All 6W
Short circuit, TC = +25°C6
See footnotes at end of table.
7
ATW2815S
TABLE III. 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
types Limits Unit
Min Max
Switching frequency FS IOUT = 1333 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 4 All -300 +300 mV pk
5,6 -450 +450
No load to/from 50 percent load 4 All -500 +500
5,6 -750 +750
Recovery time step transient
load changes 7/ 8/TTLOAD 50 percent load to/from 100 percent
load 4 All 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 5 ms
Output response to transient
step line changes 5/ 9/VOTLINE Input step 17 to 40 V dc 4,5,6 All 500 mV pk
Input step 40 to 17 V dc 4,5,6 All -1500
Recovery time transient line
changes 5/ 8/ 9/TTLINE Input step 17 to 40 V dc 4,5,6 All 800 ms
Input step 40 to 17 V dc 4,5,6 All 800
Turn on overshoot VTonOS IOUT = 0 and 1333 mA 4,5,6 All 600 mV pk
Turn on delay 10/TonD IOUT = 0 and 1333 mA 4,5,6 All 10 ms
Load fault recovery 5/TrLF 4,5,6 All 10 ms
Weight Flange 75 grams
Notes:
1/ Parameter guaranteed by line and load regulation tests.
2/ Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
3/ For operation at 16 V dc input, derate output power by 33 percent.
4/ 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.
5/ 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 III.
6/ 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.
7/ Load step transition time between 2 and 10 microseconds.
8/ 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.
9/ Input step transition time between 2 and 10 microseconds.
10/ 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.
8
BLOCK DIAGRAM
4
5
CONTROLLER
10
INPUT
FILTER
2
1
8
ERROR
AMP
& REF
6
OUTPUT
FILTER
3
Available Screening Levels and Process Variations for ATW 2800S Series
Requirement MIL-STD-883 method No Suffix ES Suffix HB Suffix CH Suffix
Temperature Range -55°C to +85°C -55°C to +115°C -55°C to +125°C -55°C to +125°C
Element Evaluation MIL-PRF-38534
Internal Visual 2017 ◆✔✔✔
Temperature Cycle 1010, Cond C Cond A ✔✔
Constant Acceleration 2001, Cond A 500g 5,000g 5,000g
Burn-in 1015 96hrs @105°C 160hrs @125°C 160hrs @125°C
Final Electrical (Group A) Specification 25°C 25°C -55, +25, +125°C -55,+25, +125°C
Seal, Fine & Gross 1014 ✔✔✔
External Visual 2009 ◆✔✔✔
◆ per Commercial Standards
PART NUMBER
ATW 28xx S / x - xxx
Model Synchronization Option
Omit for standard
Input Voltage MSTR — Master
SLV — Slave
Output Voltage Temperature Range
Single Output Omit for -55°C to +85°C (Industrial)
ES — -55°C to +105°C (Environmental)
HB — -55°C to +125°C (Military Screening)
CH — -55½C to +125°C (DESC Compliant)
9
Figure 5
Load Step Response
Load Step 0 to 6.0 ADC
(No Load to Full Load)
5.5 V
4.5 V
Figure 6
Load Step Response
Load Step 3.0 to 0 ADC
(Full Load to No Load)
TYPICAL CHARACTERISTICS
Waveforms shown are for ATW2805
Figure 1
Output Ripple Voltage
VIN = 28 VDC, Full Load
2 mV/div
2 µs/div
2 mA/div
2 µs/div
Figure 2
Input Ripple Voltage
VIN = 28 VDC, Full Load
Figure 3
Turn-on Response @Full Load
2 ms/div
1 mV/div 1 mV/div
100 µs/div
Figure 4
Turn-on Response, @Full Load
2 ms/div
100 mV/div
5.5 V
100 mV/div
4.5 V 100 µs/div
10
TYPICAL CHARACTERISTICS (Continued)
100 mV/div
5.5 V
4.5 V 50 µs/div
Figure 7
Load Step Response
Load Step 3.0 ADC to 6.0 ADC
(Half Load to Full Load)
100 mV/div
6.5 V
4.5 V 50 µs/div
Figure 8
Load Step Response
Load Step 6.0 ADC to 3.0 ADC
(Full Load to Half Load)
Figure 10
Line Step Response
A:Output @ 100 mV/div, Full Load
B:Input Step 40 VDC to 19 VDC
100 µs/div
Figure 9
Line Step Response
A:Output @ 100 mV V/div, Full Load
B:Input step @ 19 VDC to 40 VDC
100 µs/div
11
TYPICAL CHARACTERISTICS (Continued)
MECHANICAL OUTLINE
Figure 12
Audio Rejection with AFC461 EMI Filter
PIN DESIGNATION
Pin 1Positive input Pin 10Input common
Pin 2Inhibit input Pin 9N/C
Pin 3Neg. remote sense*Pin 8N/C**
Pin 4Output common Pin 7Case ground
Pin 5Positive output Pin 6Pos. remote sense*
*ATW2805S only. ATW2812S, ATW2815S have N/C.
**Or synchronization option.
10
6
1
5
Bottom
View
1.00 ± 0.005
(25.400 ± 0.127)
1.350 max
(34.290)
0.162D ± 0.005 2 places
(4.115 ± 0.127)
2.700 max
(68.580)
1.950 max
(49.530)
0.500 max
(12.700)
0.050 max
(1.270)
4 x 0.400 ± 0.005 =
(10.160 ± 0.127) 1.600 ± 0.010
(40.640 ± 0.254)
0.040D ± 0.002 x 0.260L ± 0.010
(1.016 ± 0.050) (6.604 ± 0.254)
Pin #1
2.360 ± 0.005
(59.944 ± 0.127)
0.090R max
12
APPLICATION INFORMATION
Inhibit Function
Connecting the inhibit input (Pin 2) to input com-
mon (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 400 µA of current. The open cir-
cuit voltage of the inhibit input is 11.5 ±1 VDC.
EMI Filter
An optional EMI filter (AFC461) will reduce the in-
put ripple current to levels below the limits im-
posed by MIL-STD-461 CEO3.
Remote Sense (ATW2805S only)
Better than 0.1% line and load regulation (case
temperature constant) are typical when the re-
mote sense leads are used. If the remote sense
leads are left unconnected, then the output volt-
age (measured at pins 4 and 5) will rise approxi-
mately 5.4 VDC.
If the remote sense leads are shorted together,
the output voltage may rise above 10 VDC de-
pending on load, posibly damaging both the con-
verter and load.
Device Synchronization
Whenever multiple DC/DC converters are utilized
in a single system, significant low frequency noise
may be generated due to slight differences 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 synchron-
ization of multiple AHE/ATW type converters, thus
eliminating this type of noise. Typical Synchronization Connection Diagram
To take advantage of this capability, the system
designer must assign one of the converters as the
master. Then, by definition, the remaining con-
verters become slaves and will operate at the
masters’ switching frequency. The user should
be aware that the synchronization 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
synchronization output (pin 8) of the master de-
vice is connected to the synchronization input (pin
8) of each slave device. It is advisable to keep
this run short to minimize the possibility of radiat-
ing the 250 KHz switching frequency.
The appropriate parts must be ordered to utilize
this feature. After selecting the converters re-
quired for the system, a ‘MSTR’ suffix is added
for the master converter part number and a ‘SLV’
suffix is added for slave part number. See Part
Number section.
STANDARDIZED MILITARY DRAWING
CROSS REFERENCE
Standardized Vendor Vendor
military drawing CAGE similar
PIN number PIN
5962-9157904HZX 52467 ATW2805S/CH
5962-9157905HZX 52467 ATW2805S/CH-SLV
5962-9157906HZX 52467 ATW2805S/CH-MSTR
5962-921101HZX 52467 ATW2812S/CH
5962-921102HZX 52467 ATW2812S/CH-SLV
5962-921103HZX 52467 ATW2812S/CH-MSTR
5962-9159904HZX 52467 ATW2815S/CH
5962-9159905HZX 52467 ATW2815S/CH-SLV
5962-9159906HZX 52467 ATW2815S/CH-MSTR
Output Power (Watts)
Efficiency (%)
ATW2805S EFFICIENCY
FILTER ATW2805S/ES-MSTR
ATW2815D/ES-SLV
SLAVE
ATW2812S/ES-SLV
SLAVE
+5V
COMM
+15V
COMM
-15V
+12V
COMM
5
4
5
4
3
4
5
1
10
1
10
1
10
8
2
8
SYSTEM
BUS
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. These specifications are subject to change without notice. 9848
LAMBDA ADVANCED ANALOG INC. λMIL-PRF-38534 Certified
ISO9001 Registered 2270 Martin Avenue
Santa Clara CA 95050-2781
(408) 988-4930 FAX (408) 988-2702
NOTES
