PD-94557A
ATW28XXD SERIES
28V Input, Dual Output
HYBRID-HIGH RELIABILITY
DC/DC CONVERTERS
Description
The ATW28XXD 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
operate with a 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 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 elements
in the feedback circuits.
Manufactured in a facility fully qualified to MIL-PRF-
38534, these converters are fabricated utilizing DSCC
qualified processes. For available screening options,
refer to device screening table in the data sheet.
Variations in electrical, mechanical and screening can
be accommodated. Contact IR Santa Clara for special
requirements.
ATW
Features
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18V to 40VDC Input Range (28VDC Nominal)
±
12V and
±
15V Outputs Available
Indefinite Short Circuit and Overload Protection
3
22.8W/in Power Density
30W Output Power
Fast Loop Response for Superior Transient
Characteristics
Operating Temperature Range from -55°C to
+125°C Available
Popular Industry Standard Pin-Out
Resistance Seam Welded Case for Superior
Long Term Hermeticity
Efficiencies up to 85%
Shutdown from External Signal
Full Military Screening
200,000 hour MTBF at 85°C
Standard Microcircuit Drawings Available
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1
12/14/06
ATW28XXD Series
Specifications
Absolute Maximum Ratings
Input voltage
Soldering temperature
Operating case temperature
Storage case temperature
-0.5V to +50VDC
300°C for 10 seconds
-55°C to +125°C
-65°C to +135°C
ATW2812D
Table I. Electrical Performance Characteristics
Test
Symbol
Conditions
-55°C
≤Tc ≤+125°C
Vin = 28 Vdc ±5%, C
L
= 0
Unless otherwise specified
I
OUT
= 0
V
IN
= 18, 28, and 40 V dc,
each output
V
IN
= 18, 28, and 40 V dc,
B.W. = 20Hz to 2MHz
V
IN
= 18, 28, and 40 V dc,
Iout = 0,1250, and 2500mA
V
IN
= 18, 28, and 40 V dc,
I
OUT
= 0, 1250, and 2500mA
10% to 90% load change
I
OUT
= 0, inhibit (pin 8)
tied to input return (pin 10)
I
OUT
= 0,inhibit (pin 8)=
open
I
OUT
= 2500mA
B.W. = 20Hz to 2MHz
I
OUT
= 2500mA
T
C
= +25°C
Input to output or any pin
to case (except pin 7) at
500 V dc Tc = +25°C
No effect on dc
performance, Tc = +25°C,
total for both outputs
8
Overload, T
C
= +25°C
Short circuit, T
C
= +25°C
I
OUT
= 2500mA
Group A
Subgroups
Device
Types
Limits
Unit
Output voltage
Output current
1, 2
3
V
OUT
I
OUT
V
RIP
VR
LINE
VR
LOAD
VR
CROSS
I
IN
1
2,3
1,2,3
1,2,3
1
2,3
1,2,3
1,2,3
1,2,3
All
All
All
All
All
All
All
Min
±11.88
±11.76
250
Max
±12.12
±12.24
2250
85
30
60
120
3.5
18
50
V
mA
mVp-p
mV
mV
%
mA
Output ripple voltage
Line regulation
4
Load regulation
4
5
Cross regulation
Input current
Input ripple current
Efficiency
Isolation
Capacitive load
6, 7
4
3, 4
I
RIP
E
FF
ISO
C
L
P
D
1,2,3
1
1
4
1
4,5,6
All
All
All
All
All
01
02
03
All
250
250
275
-400
80
100
50
mAp-p
%
MΩ
200
12
9.0
300
270
300
+400
µF
W
KHz
Power dissipation
load fault
Switching frequency
4
F
S
Output response to step
transient load
4, 9
changes
Recovery time step
transient load
4, 9, 10
changes
VO
TLOAD
1250mA to/from 2500mA
4,5,6
mV pk
TT
LOAD
0mA to/from 2500mA
1250mA to/from 2500mA
4,5,6
4,5,6
All
All
-800
+800
70
µs
0mA to/from 1250mA
1250mA to/from 0mA
4,5,6
4,5,6
All
All
500
5.0
ms
For Notes to Specifications, refer to page 3
2
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ATW28XXD Series
Table I. Electrical Performance Characteristics -
continued
Test
Symbol
Conditions
-55°C
≤Tc ≤+125°C
Vin = 28 Vdc ±5%, C
L
= 0
unless otherwise specified
Input step from/to 18 to 40
Vdc, I
OUT
= 2500mA
Input step from/to 18 to 40
Vdc, I
OUT
= 2500mA
I
OUT
= 0 and 2500mA
I
OUT
= 0 and 2500mA
Group A
Subgroups
Device
Types
Limits
ATW2812D
Unit
Output response
transient step line
4, 7, 11
changes
Recovery time
transient step line
4, 7, 10, 11
change
4
Turn on overshoot
4, 12
Turn on delay
Load fault recovery
Weight
7
VO
TLINE
TT
LINE
VTon
OS
Ton
D
Tr
LF
4,5,6
All
Min
-800
Max
+800
mV pk
4,5,6
All
4000
µs
mV pk
ms
ms
g
4,5,6
4,5,6
4,5,6
All
All
All
750
14
14
75
Flange
Notes to Specifications
1
2
3
4
5
6
7
8
9
10
11
12
Parameter guaranteed by line, load and cross regulation tests.
Up to 90% of full power is available from either output provided the total output does not exceed 30W.
Bandwidth guaranteed by design. Tested for 20KHz to 2MHz.
Load current split equally between +V
OUT
and –V
OUT
.
Three-watt load on output under test, 3.0W to 27W load change on other output.
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.
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.
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.
Load step transition time between 2.0µs and 10µs.
Recovery time is measured from the initiation of the transient to where V
OUT
has returned to within ±1.0% of V
OUT
at 50%load.
Input step transition time between 2.0µs and 10µs.
Turn-on delay time measurement is for either a step application of power at the input or the removal of
ground signal from the inhibit pin (pin 8) while power is applied to the input.
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3
ATW28XXD Series
Specifications
Absolute Maximum Ratings
Input voltage
Soldering temperature
Operating case temperature
Storage case temperature
-0.5V to +50VDC
300°C for 10 seconds
-55°C to +125°C
-65°C to +135°C
ATW2815D
Table II. Electrical Performance Characteristics
Test
Symbol
Conditions
-55°C
≤Tc ≤+125°C
Vin = 28 Vdc ±5%, C
L
= 0
Unless otherwise specified
V
IN
= 18, 28, and 40 Vdc
I
OUT
= 0
V
IN
= 18, 28, and 40 V dc
V
IN
= 18, 28, and 40 V dc,
B.W. = DC to MHz
V
IN
= 18, 28, 40 Vdc
V
IN
= 18, 28, and 40 V dc,
Iout = 0, 1000, and 2000mA
V
IN
= 18, 28, and 40 V dc,
I
OUT
= 0, 1000, and 2000mA
I
OUT
= 0, inhibit (pin 8)
I
OUT
= 0, inhibit (pin 8) = open
I
OUT
= 2000mA
I
OUT
= 2500mA T
C
= 25°C
Input to output or any pin
to case (except pin 8) at
500V dc Tc = 25°C
No effect on dc performance,
Tc = 25°C
3
Overload, T
C
= +25°C
Short circuit, T
C
= +25°C
I
OUT
= 2000mA
50% load to/from 100% load
Group A
Subgroups
Device
Types
Limits
Unit
Output voltage
Output current
Output ripple voltage
Output Power
Line regulation
4, 11
9, 10
11, 13
V
OUT
8
I
OUT
V
RIP
P
OUT
VR
LINE
VR
LOAD
I
IN
I
RIP
E
FF
ISO
C
L
P
D
F
S
VO
TLOAD
1
2,3
1,2,3
1,2,3
1,2,3
1
2,3
1,2,3
1,2,3
1,2,3
1,2,3
1
1
4
1
1
1,2,3
1,2,3
1,2,3
4,5,6
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
01
02
03
All
Min
±14.85
±14.70
0.200
Max
±15.15
±15.30
2000
85
V
DC
V
DC
mA
DC
mVp-p
W
mV
mV
mV
mADC
mADC
mAp-p
%
MΩ
µF
W
W
KHz
KHz
KHz
mV pk
30
35
75
150
12
30
60
80
100
500
9.0
9.0
263
245
265
+300
Load regulation
Input current
9, 10
Input ripple current
Efficiency
Isolation
Capacitive load
6, 12
Power dissipation
load fault
Switching frequency
Output response to step
transient
7, 9, 10
load changes
237
230
250
-300
Recovery time step
1, 7
transient load changes
TT
LOAD
No load to 100% load
100% load to no load
50% load to/from 100% load
No load to 50% load
50% load to no load
4,5,6
4,5,6
4,5,6
4,5,6
4,5,6
All
All
All
All
All
-800
+800
-800
+800
25
500
7.0
mV pk
mV pk
µs
µs
ms
For Notes to Specifications, refer to page 5
4
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ATW28XXD Series
Table II. Electrical Performance Characteristics -
continued
Test
Symbol
Conditions
-55°C
≤Tc ≤+125°C
Vin = 28 Vdc ±5%, C
L
= 0
unless otherwise specified
Input step from/to 18 to
40VDC
Input step from 40 to18 VDC
Input step from/to 18 to 40
VDC
Input step from 40 to 18 VDC
I
OUT
= 0 and 2000mA
I
OUT
= 0 and 2000mA
V
IN
= 18 to 40 VDC
Flange
Group A
Subgroups
Device
Types
Min
Output response
transient step line
5, 12
changes
Recovery time
transient step line
1. 5, 12
changes
Turn on overshoot
2
Turn on delay
Load fault recovery
Weight
12
ATW2815D
Limits
Unit
Max
+180
mV pk
VO
TLINE
4,5,6
All
TT
LINE
4,5,6
4,5,6
All
All
-600
400
mV pk
µs
µs
mV pk
ms
ms
g
VTon
OS
Ton
D
Tr
LF
4,5,6
4,5,6
4,5,6
4,5,6
All
All
All
All
400
750
12
12
75
Notes to Specifications
1
2
3
4
5
6
7
8
9
10
11
12
13
Recovery time is measured from the initiation of the transient to where V
OUT
has returned to within
±1.0%
of V
OUT
at 50% load.
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 8) while power is applied to the input.
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.
Above +125°C case, derate output power linearly to 0 at +135°C case.
Input step transition time between 2.0µs and 10µs.
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 will interfere with the operation of the load fault detection circuitry,
appearing as a short circuit during turn on.
Load step transition time between 2.0µs and 10µs.
Bandwidth guaranteed by design. Tested for 20KHz to 2MHz.
Load current split equally between +V
OUT
and –V
OUT
.
When operating with unbalanced loads, at least 25% of the load must be on the positive output to maintain regulation.
Parameter guaranteed by line and load regulation tests.
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.
Up to 90% of full power is available from either output provided the total output does not exceed 30W.
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5