Document
HYBRID-HIGH RELIABILITY DC-DC CONVERTER
PD-94541E
AHF SERIES
28V Input, Single/Dual Output
Description
The AHF Series of DC-DC converters feature single or dual outputs over the full military temperature range. No derating in output power is required, making them suitable for use in rugged military applications. The low profile, small outline package is ideally suited to the tight board space requirements of many industrial and aerospace applications. Designed for nominal 28Vdc inputs, this family of converters will meet the requirements of MIL-STD-704D. The basic circuit utilizes a pulse width modulated, feed-forward topology 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 proprietary magnetic feedback circuit provides for an extremely wide bandwidth control loop with a high phase margin. The closed loop frequency response of this converter family extends to approximately 50kHz, resulting in superior line and load transient characteristics. This feedback method is also inherently temperature and radiation insensitive. This gives the AHF Series an important advantage over converters that incorporate opto-couplers in their design.
Manufactured in a facility fully qualified to MIL-PRF-38534, these converters are fabricated utilizing DLA qualified process. For available screening options, refer to device screening table in the data sheet. Variations are electrical, mechanical and screening can be accommodated.
Extensive computer simulation using complex modeling enables rapid design modification to be provided. Contact IR HiRel San Jose with specific requirements.
AHF
Features
16V to 40VDC Input Range (28VDC Nominal) Single and Dual Outputs 12W Output Power 22.8W/in3 Power Density Low Input / Output Noise
(50mA / 60mVP-P max. respectively) Indefinite Short Circuit and Overload Protection Wideband Control Loop for Superior Transient
Characteristics No derating for -55°C to +125°C Operation Constant Switching Frequency
(550kHz Nominal) Standard Microcircuit Drawings Available
1 2017-05-08
AHF SERIES
(28V Input, Single/Dual Output)
Specifications
Absolute Maximum Ratings Input Voltage Soldering temperature Operating case temperature Storage case temperature
-0.5Vdc to +50VDC +300°C for 10 seconds -55°C to +125°C -65°C to +135°C
Table I. Electrical Performance Characteristics
AHF2803R3S
Parameter
Symbol
Conditions -55°C TC +125°C VIN = 28 VDC ± 5%, CL = 0 Unless otherwise specified
Group A Subgroups
Device Types
Limits Min Max
Unit
Output voltage Output current1
VOUT IOUT = 5% of rated load IOUT VIN = 16, 28, and 40Vdc
1 2,3 1,2,3
3.26 3.34 01 3.23 3.36 V 01 3030 mA
Output power
POUT VIN = 16, 28, and 40Vdc
1,2,3
01
10 W
Output ripple voltage2 Line regulation Load regulation
Input current Input ripple current2
VRIP VRLINE VRLOAD
IIN IRIP
VIN = 16, 28, and 40Vdc, B.W. = 20 Hz to 2MHz VIN = 16, 28, and 40Vdc, IOUT = 5%, 50% and 100% rated load VIN = 16, 28, and 40Vdc, IOUT = 5%, 50% and 100% rated load IOUT = 0, Inhibit (Pin 1) tied to Input Return (Pin 7) IOUT = 0, Inhibit (Pin 1) = open IOUT = 100% rated load B.W. = 20 Hz to 2 MHz
1,2,3 1,2,3 1,2,3
01 01 01
1,2,3
01
1,2,3
01
60 mVp-p
25 mV
50 mV
12 mA
30 50 mAp-p
Efficiency
Isolation
Capacitive load3,4 Power dissipation load fault
EFF IOUT = 100% rated load
Input to output or any pin ISO to case (except Pin 6) at
500Vdc TC = +25°C
CL
No effect on dc performance, TC = +25°C
PD Overload 5 Short circuit
1 2,3 1
4 1 1,2,3
01 70 68
01 100
% M
01 500 µF
01 6.0 W 01 2.0
Switching frequency
FS IOUT = 100% rated load
4,5,6
01 500 600 kHz
For Notes to Electrical Performance Characteristics, refer to page 3
2 2017-05-08
AHF SERIES
(28V Input, Single/Dual Output)
Table I. Electrical Performance Characteristics (continued)
Parameter
Output response to step transient load changes6
Recovery time step transient load changes6.7
Symbol
Conditions -55°C TC +125°C VIN = 28 VDC ± 5%, CL = 0 unless otherwise specified
Group A Subgroups
VOTLOAD
50% to/from 100% rated load
5% to/from 50% rated load
4,5,6 4,5,6
TTLOAD
50% to/from 100% rated load
4,5,6
5% to 50% rated load
4,5,6
Output response to transient step line changes
Recovery time transient step line changes
Turn on overshoot
Turn on delay
50% to 5% rated load
VOTLINE
TTLINE VTonOS TonD
Input step 16V to/from 40Vdc, IOUT = 100% rated load 4, 8
Input step 16V to/from 40Vdc, IOUT = 100% rated load 4, 7, 8
IOUT = 5 and 100% rated load
IOUT = 5 and 100% rated load 9
4,5,6 4,5,6
4,5,6 4,5,6 4,5,6
Load fault recovery4,9 Weight
TrLF
4,5,6
Device Types
01
01
01 01 01 01 01
AHF2803R3S
Limits Min Max
Unit
-300 +300 -500 +500
mVpk
70 µs
1200 8.0
µs ms
500 mVpk
800 µs
600 mVpk 20 ms 20 ms 38 g
Notes to Table I:
1. P.