PD - 94556
ATW28XXS SERIES
ADVANCED ANALOG
HYBRID-HIGH RELIABILITY
DC/DC CONVERTERS
Description
The ATW28XXS 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 op-
erate with a nominal 28 VDC input and are available
with single outputs at 5V,12V and 15V. The circuit de-
sign incorporates a pulse width modulated push-pull
topology operating in the feed-forward mode at a nomi-
nal 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 re-
sponse for superior line and load transient character-
istics and offers greater reliability and radiation toler-
ance than devices incorporating optical elements in
the feedback circuits.
Three standard temperature grades are offered. Refer
to Part Number section. These devices are provided in
a flanged package for secure mounting in severe envi-
ronments.
Manufactured in a facility fully qualified to MIL-PRF-
38534, these converters are available in four screen-
ing 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 does not
incorporate the element evaluation and Periodic In-
spection (PI) requirements of MIL-PRF-38534. 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 a more
limited screening process are also available for use in
less demanding applications. Variations in electrical,
mechanical and screening can be accommodated.
Contact Advanced Analog for special requirements.
28V Input, Single Output
ATW
Features
n
19 to 40 VDC Input Range (28 VDC Nominal)
n
30 Watts Output Power
n
Indefinite Short Circuit and Overload
Protection
3
n
22.8 W/in Power Density
n
Fast Loop Response for Superior Transient
Characteristics
n
Operating Temperature Range from -55°C to
+125°C Available
n
Popular Industry Standard Pin-Out
n
Resistance Seam Welded Case for Superior
Long Term Hermeticity
n
Efficiencies up to 83%
n
Shutdown from External Signal
n
Military Screening
n
250,000 hour MTBF at 85°C
n
MIL-PRF-38534 Compliant Versions
Available
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1
10/25/02
ATW28XXS Series
Specifications
§
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Soldering Temperature
Case Temperature
-0.5V to 50V
300°C for 10 seconds
Operating -55°C to +125°C
Storage -65°C to +135°C
ATW2805S
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
= 19, 28, and 40 V dc
V
IN
= 19, 28, and 40 V dc,
B.W. = dc to 2MHz
V
IN
= 19,28, and 40 V dc
V
IN
= 19, 28, and 40 V dc,
Iout = 0, 3000, and 6000mA
V
IN
= 19, 28, and 40 V dc,
I
OUT
= 0, 3000, and 6000mA
I
OUT
= 0, inhibit (pin 2)
tied to input return (pin 10)
I
OUT
= 0, inhibit (pin 2) = open
I
OUT
= 6000mA
B.W. = dc to 2MHz
I
OUT
= 6000mA
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
7
Overload, T
C
= +25°C
Short circuit, T
C
= +25°C
I
OUT
= 6000mA
Group A
Subgroups
Device
Types
Limits
Unit
Output voltage
Output current
2
Output ripple voltage
Output power
4
Line regulation
1, 3
1
V
OUT
I
OUT
V
RIP
P
OUT
VR
LINE
VR
LOAD
I
IN
2
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
Min
4.95
4.90
0
Max
5.05
5.10
6000
50
V
mA
mVp-p
W
mV
30
5
20
30
18
40
20
78
100
Load regulation
Input current
4
All
All
mV
mA
Input ripple current
Efficiency
Isolation
5, 6
I
RIP
E
FF
ISO
1,2,3
1
1
All
All
All
mAp-p
%
MΩ
Capacitive load
C
L
P
D
4
1
All
All
500
12
9
300
270
300
+500
+500
µF
W
Power dissipation
load fault
Switching frequency
F
S
4,5,6
Output response to step
8
transient load changes
VO
TLOAD
4000mA to/from 6000mA
500mA to/from 2500mA
4,5,6
4,5,6
01
02
03
All
250
250
275
-500
-500
KHz
mV
pk
For Notes to Specifications, refer to page 3
2
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ATW28XXS Series
Table I. Electrical Performance Characteristics -
continued
Test
Symbol
ATW2805S
Device
Types
Conditions
-55°C
≤
Tc
≤+125°C
Vin = 28 Vdc ±5%, C
L
= 0
unless otherwise specified
4000mA to/from 6000mA
Group A
Subgroups
Limits
Unit
Min
Recovery time step
8, 9
transient load changes
TT
LOAD
4
5,6
4
5,6
4,5,6
4,5,6
4,5,6
All
Max
100
200
100
200
500
12
12
µs
500mA to 2500mA
Turn on overshoot
10
Turn on delay
Load fault recovery
6, 10
All
All
All
All
VTon
OS
Ton
D
Tr
LF
I
OUT
= 0 and 6000mA
I
OUT
= 0 and 6000mA
mV
pk
ms
ms
Notes to Specifications
1
2
3
4
5
Parameter guaranteed by line and load regulation tests.
Bandwidth guaranteed by design. Tested for 20 kHz to 2 MHz.
Above +125°C case, derate output power linearly to 0 at +135°C.
Output voltage measured at load with remote sense leads connected across load.
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 and 10 microseconds.
Recovery time is measured from the initiation of the transient to where V
OUT
has returned to within ±1
percent of V
OUT
at 50 percent load.
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 1) while power is applied to the input is unlimited.
6
7
8
9
10
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3
ATW28XXS Series
Specifications
§
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Soldering Temperature
Case Temperature
-0.5V to 50V
300°C for 10 seconds
Operating -55°C to +125°C
Storage -65°C to +135°C
ATW2812S
Table II. Electrical Performance Characteristics
Test
Symbol
Conditions
-55°C
≤
Tc
≤
+125°C
Vin = 28 Vdc ±5%, C
L
= 0
Unless otherwise specified
Group A
Subgroups
Device
Types
Limits
Unit
Output voltage
Output current
2
Output ripple voltage
Line regulation
1
V
OUT
I
OUT
V
RIP
VR
LINE
I
OUT
= 0
V
IN
= 18, 28, and 40 V dc
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
I
OUT
= 0, inhibit (pin 2)
tied to input return (pin 10)
I
OUT
= 0, inhibit (pin 2) = open
I
OUT
= 2500mA
B.W. = 20Hz to 2MHz
I
OUT
= 2500mA
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
5
Overload
Short circuit
I
OUT
= 2500mA
1
2,3
1,2,3
1,2,3
1
2,3
1,2,3
1,2,3
All
All
All
All
Min
11.88
11.76
Max
12.12
12.24
2500
50
±30
±60
±120
18
50
20
V
mA
mVp-p
mV
Load regulation
Input current
VR
LOAD
I
IN
2
All
All
mV
mA
Input ripple current
Efficiency
Isolation
3, 4
I
RIP
E
FF
ISO
1,2,3
1
2,3
1
All
All
All
78
75
100
mAp-p
%
MΩ
Capacitive load
C
L
P
D
4
1
1,2,3
4,5,6
All
All
200
12
9
300
270
300
+800
µF
W
Power dissipation
load fault
Switching frequency
F
S
Output response to
step transient load
6
changes
VO
TLOAD
1250mA to/from 2500mA
4,5,6
01
02
03
All
250
250
275
-800
KHz
mVpk
0mA to/from 1250mA
-1000
+1000
For Notes to Specifications, refer to page 5
4
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ATW28XXS 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
Group A
Subgroups
Device
Types
ATW2812S
Limits
Unit
Min
Recovery time step
6, 7
transient load changes
TT
LOAD
1250mA to/from 2500mA
4
5,6
4
5,6
4,5,6
All
Max
100
200
5
10
+1000
µs
0mA to 1250mA
Output response to
Transient step
Line changes
Recovery time
Transient step
Line changes
Turn on overshoot
Turn on delay
Load fault recovery
4, 9
All
All
-1000
ms
mVpk
VO
TLINE
TT
LINE
VTon
OS
Ton
D
Tr
LF
Input step 18V to/ from
40V dc,
4, 8
I
OUT
= 2500mA
Input step 18V to/ from
40V dc
4, 7, 8
I
OUT
= 2500mA
I
OUT
= 0 and 2500mA
9
I
OUT
= 0 and 2500mA
4,5,6
All
500
µs
4,5,6
4,5,6
4,5,6
All
All
All
600
12
12
mVpk
ms
ms
Notes to Specifications
1 Parameter guaranteed by line and load regulation tests.
2 Bandwidth guaranteed by design. Tested for 20 kHz to 2 MHz.
3 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.
4 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.
5 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.
6 Load step transition time between 2 and 10 microseconds.
7 Recovery time is measured from the initiation of the transient to where V
OUT
has returned to within ±1
percent of V
OUT
at 50 percent load.
8 Input step transition time between 2 and 10 microseconds.
9 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 2) while power is applied to the input.
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5