PD - 94549B
ATR28XXS SERIES
28V Input, Single Output
HYBRID-HIGH RELIABILITY
DC/DC CONVERTER
Description
The ATR28XXS 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-704D input requirements, these devices
have nominal 28VDC inputs with 3.3V, 5V, 12V and
15V single outputs to satisfy a wide range of requirements.
The circuit design incorporates a pulse width modulated
single forward topology operating in the feed-forward
mode at a nominal switching frequency of 550KHz.
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 with
screening options. Refer to Part Number section. These
devices can be provided in a standard plug-in package
for PC mounting or in a flanged package for more
severe environments.
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.
Extensive computer simulation using complex modeling
enables rapid design modification to be provided.
Contact IR Santa Clara with specific requirements.
ATR
Features
16V to 40VDC Input Range (28VDC Nominal)
3.3V, 5V, 12V and 15V Outputs Available
Indefinite Short Circuit and Overload
Protection
3
Up to 35W/in Power Density
30W Output Power Models
Fast Loop Response for Superior Transient
Characteristics
Operating Temperature Range from -55°C to
+125°C
Popular Industry Standard Pin-Out
Resistance Seam Welded Case for Superior
Long Term Hermeticity
Ceramic Feed-thru Pins
External Synchronization
Efficiencies up to 84%
Shutdown from External Signal
Military Screening
Standard Microcircuit Drawings Available
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1
01/15/07
ATR28XXS 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
ATR2803R3S
Table I. Electrical performance Characteristics
Test
Symbol
Conditions
-55°C
≤
TC
≤
+125°C
V
IN
= 28VDC
±5%,
C
L
= 0
Unless otherwise specified
I
OUT
= 0
V
IN
= 16, 28, and 40 VDC
V
IN
= 16, 28, and 40 VDC
B.W. = 20Hz to 2 MHz
V
IN
= 16, 28, and 40 VDC
I
OUT
= 0, 3000, and 6000mA
V
IN
= 16,28, and 40 VDC
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. = 20Hz to 2 MHz
I
OUT
=6000mA
Input to output or any pin
to case (except pin 8) at
500 VDC, TC =+25°C
No effect on dc performance
TC =+25°C
6
Overload, TC = +25°C
Short Circuit
I
OUT
= 7500mA
I
OUT
= 7500mA
Load step 50% to/from 100%
Load step 50% to/from 100%
Load step 50% to/from 100%
Load step 50% to/from 100%
Output response to transient
5, 9
step line changes
VO
TLINE
Input step 16V to/from
40VDC, I
OUT
= 7500mA
Group A
Subgroups
Device
Types
Limits
Min
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
4
1
01
1,2,3
4,5,6
4,5,6
4,5,6
4,5,6
4
5,6
4
5,6
4,5,6
01
01
01
500
500
-500
-500
9.0
600
700
+500
+500
100
200
100
200
±500
01
01
01
01
3.25
3.20
Max
3.35
3.40
7500
60
±20
±30
±50
18
50
50
74
70
100
500
12
W
KHz
KHz
mV pk
V
mA
mV p-p
mV
Units
Output voltage
Output current
2
Output ripple voltage
Line regulation
3
1
V
OUT
I
OUT
V
RIP
VR
LINE
VR
LOAD
I
IN
2
Load regulation
Input current
3
01
01
01
01
01
01
mV
mA
mA p-p
%
MΩ
µF
Input ripple current
Efficiency
Isolation
I
RIP
E
FF
ISO
Capacitive load
4, 5
C
L
P
D
F
S
F
SYNC
VO
TLOAD
TT
LOAD
Power dissipation
load fault
Switching frequency
Sync frequency range
Output response to step
7
transient load changes
Recovery time step
7, 8
transient load changes
01
µs
01
mV pk
For Notes to Specifications, refer to page 3
2
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ATR28XXS Series
Table I. Electrical performance Characteristics -
continued
Symbol
Conditions
-55°C
≤
TC
≤
+125°C
V
IN
= 28VDC
±5%,
C
L
= 0
Unless otherwise specified
Input step 16V to/from
40VDC, I
OUT
= 7500mA
I
OUT
= 10% to 100% of Load
I
OUT
=0 and 7500mA
Group A
Subgroups
Device
Types
ATR2803R3S
Limits
Min
Max
10
350
25
25
ms
mV pk
ms
ms
Units
Recovery time transient step
5, 8, 9
line changes
Turn on overshoot
10
Turn on delay
5, 10
Load fault recovery
TT
LINE
VTon
OS
Ton
D
Tr
LF
4,5,6
4,5,6
4,5,6
4,5,6
01
01
01
01
Notes to Specifications
Parameter guaranteed by line and load regulation tests.
Bandwidth guaranteed by design. Tested for 20KHz to 2.0MHz.
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.
5 Parameter shall be tested as part of design characterization and after design or process changes. There after parameters shall be
guaranteed to the limits specified in table I.
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 2.0µs and 10µs.
8 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.
9 Input step transition time between 2.0µs and 10µs.
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.
1
2
3
4
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3
ATR28XXS 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
ATR2805S
Table II. Electrical performance Characteristics
Test
Symbol
Conditions
-55°C
≤
TC
≤
+125°C
V
IN
= 28VDC
±5%,
C
L
= 0
Unless otherwise specified
I
OUT
= 0
V
IN
= 16, 28, and 40 VDC
V
IN
= 16, 28, and 40 VDC
B.W. = 20Hz to 2 MHz
V
IN
= 16, 28, and 40 VDC
I
OUT
= 0, 3000, and 6000mA
V
IN
= 16,28, and 40 VDC
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. = 20Hz to 2 MHz
I
OUT
=6000mA
Input to output or any pin
to case (except pin 8) at
500 VDC, TC =+25°C
No effect on dc performance
TC =+25°C
6
Overload, TC = +25°C
Short Circuit
I
OUT
= 6000mA
I
OUT
= 6000mA
3000mA to/from 6000mA
500mA to/from 3000mA
3000mA to/from 6000mA
500mA to/from 3000mA
Output response to transient
5, 9
step line changes
VO
TLINE
Input step 16V to/from
40VDC, I
OUT
= 6000mA
Group A
Subgroups
Device
Types
Limits
Min
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
4
1
01
1,2,3
4,5,6
4,5,6
4,5,6
4,5,6
4
5,6
4
5,6
4,5,6
01
01
01
500
500
-500
-500
9.0
600
700
+500
+500
100
200
100
200
±500
01
01
01
01
4.95
4.90
Max
5.05
5.10
6000
60
±20
±30
±50
18
50
50
76
72
100
500
12
W
KHz
KHz
mV pk
V
mA
mV p-p
mV
Units
Output voltage
Output current
2
Output ripple voltage
Line regulation
3
1
V
OUT
I
OUT
V
RIP
VR
LINE
VR
LOAD
I
IN
2
Load regulation
Input current
3
01
01
01
01
01
01
mV
mA
mA p-p
%
MΩ
µF
Input ripple current
Efficiency
Isolation
I
RIP
E
FF
ISO
Capacitive load
4, 5
C
L
P
D
F
S
F
SYNC
VO
TLOAD
TT
LOAD
Power dissipation
load fault
Switching frequency
Sync frequency range
Output response to step
7
transient load changes
Recovery time step
7, 8
transient load changes
01
µs
01
mV pk
For Notes to Specifications, refer to page 5
4
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ATR28XXS Series
Table II. Electrical performance Characteristics -
continued
Symbol
Conditions
-55°C
≤
TC
≤
+125°C
V
IN
= 28VDC
±5%,
C
L
= 0
Unless otherwise specified
Input step 16V to/from
40VDC, I
OUT
= 6000mA
I
OUT
=0 and 6000mA
I
OUT
=0 and 6000mA
Group A
Subgroups
Device
Types
Limits
Min
4,5,6
4,5,6
4,5,6
4,5,6
01
01
01
01
ATR2805S
Units
Max
10
500
25
25
ms
mV pk
ms
ms
Recovery time transient step
5, 8, 9
line changes
Turn on overshoot
10
Turn on delay
5, 10
Load fault recovery
TT
LINE
VTon
OS
Ton
D
Tr
LF
Notes to Specifications
Parameter guaranteed by line and load regulation tests.
Bandwidth guaranteed by design. Tested for 20KHz to 2.0MHz.
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.
5 Parameter shall be tested as part of design characterization and after design or process changes. There after parameters shall be
guaranteed to the limits specified in table II.
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 2.0µs and 10µs.
8 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.
9 Input step transition time between 2.0µs and 10µs.
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.
1
2
3
4
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5
