ETC AHF2815T

PD - 94542
AHF2815T SERIES
28V Input, Triple Output
ADVANCED ANALOG
HIGH RELIABILITY
DC/DC CONVERTERS
Description
The AHF2815T Series of DC/DC converters provide 8
watts of power and an extended temperature range for
use in military and industrial applications. Designed to
the nominal input requirements of MIL-STD-704, these
devices have nominal 28VDC inputs with +5V and ±15V
triple outputs to satisfy a wide range of requirements.
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 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 Advanced Analog for special requirements.
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AHF
Features
n 16 to 40 VDC Input Range (28 VDC Nominal)
n 5V, ±15 Volt Output
n Infinite Short Circuit and Overload
Protection
n 8 Watts Output Power
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 Efficiency Up to 75%
n Shutdown from External Signal
n 400,000 Hour MTBF at 85%
n Constant Switching Frequency
(550KHz Nominal)
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10/08/02
AHF2815T Series
Specifications
TCASE = -55°C to +125°C, VIN = +28V ± 5% unless otherwise specified 7
n
TYPICAL CHARACTERISTICS
Temperature Range7
Isolation
Weight
Conversion frequency
Test
Symbol
STATIC
CHARACTERISTICS
Output voltage1
VOUT
Operating -55°C to +125°C case
Storage -65°C to +135°C
100 megaohms at 500 volts DC
35 grams
550 kHz
Conditions
-55°C ≤ Tc ≤ +125°C
Vin = 28 Vdc ±5%, CL = 0
unless otherwise specified7
IOUT = 0 (main)
IOUT = 0 (dual)1
Current1,2,3
IOUT
1,4
Ripple Voltage
VRIP
Power1,2,3
POUT
REGULATION
Line1,3
VRLINE
Load1,3
VRLOAD
Input current
IIN
Ripple current4
IRIP
Efficiency
EFF
Isolation
ISO
Load fault power
dissipation3
PD
Switching frequency
Inhibit Open
Circuit Voltage
FS
VOI
Unit
AHF2815T
Limits
TC = 25°C
Over Temp
TC = 25°C
Over Temp
VIN = 16, 28, and 40 Vdc (main)
VIN = 16, 28, and 40 Vdc (dual)
VIN = 16, 28, and 40 Vdc
BW = DC to 2 MHz (main)
VIN = 16, 28, and 40 VDC
BW = DC to 2 MHz (dual)
VIN = 16, 28, and 40 Vdc (main)
(+dual)
(-dual)
(total)
VIN = 16, 28, and 40 VDC
IOUT = 120, 600,1200 mA (main)
IOUT = 0, ±33.4, ±66.7 mA (dual)
VIN = 16, 28, and 40 VDC
IOUT = 120, 600, 1200mA (main)
IOUT = 0, ±33.4, ±66.7 mA (dual)
IOUT = 0, inhibit (pin 1)
tied to input return (pin 7)
IOUT = 0, inhibit (pin 1) = open
IOUT = 1200mA (main)
IOUT = ±66.7 mA (dual)
BW = DC to 2MHz
POUT = Full load
Input to output or any pin
to case (except pin 6) at 500
V dc Tc = +25°C
Overload, TC = ±25°C5
Short Circuit, TC = ±25°C
Min
Max
4.95
4.90
±14.50
±14.35
120
0.0
5.05
5.10
±15.50
±15.65
1200
±66.7
60
V
V
V
V
mA
mA
mV p-p
80
mV p-p
W
W
W
W
5
1.5
1.5
8
TC = 25°C
Over Temp
TC = ±25°C
TC = ±25°C
TC = ±25°C
25
±35
±75
mV
mV
mV
50
±75
15
mV
mV
mA
50
50
mA
mA p-p
68
%
100
MΩ
TC = ±25°C
500
9
8
6
W
W
600
13
kHz
V
For Notes to Specifications, refer to page 3
2
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AHF2815T Series
Notes to Specifications
1.
2.
3.
4.
5.
6.
7.
Tested at each output.
Parameter guaranteed by line and load regulation tests.
At least 20 percent of the total output power should be taken from the (+5 volt) main output.
Bandwidth guaranteed by design. Tested for 20 KHz to 2 MHz.
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 temperature, derate output power linearly to 0 at 135 °C case.
TCASE = -55°C to 85°C for non screened grade.
AHF2815T Block Diagram
2 + V out
F ilter
&
R egulator
EMI
F ilter
8
+ Inp ut
4
5 + V out
P rim ary
H ouse keep ing
S upply
6
C ase
-V out
3 R eturn
D riv e
P ulse W idth
FB
M odulator
1
E rror
Amp &
R ef
E nable
CS
In put
R eturn
7
Application Information
Inhibit Function
Connecting the inhibit input (Pin 1) to input common (Pin 7)
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
circuit voltage of the inhibit input is 11.5 ±1 VDC.
Thermal Management
Assuming that there is no forced air flow, the package temperature rise above ambient (∆T) may be calculated using
the following expression:
∆T = 80 A
–0.7
p
0.85
(°C)
where A = the effective surface area in square inhes(including heat sink if used), P = power dissipation in watts.
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The total surface area of the AHF package is 4.9 square
inches. If a worse case full load efficiency of 75% is assumed, then the case temperature rise can be calculated
as follows:
 1

 1

− 1 = 8
− 1 = 2.66W
P = POUT 
 .78 
 Eff

∆T = 80 (4.9)
-0.7
(2.66)
0.85
= 60.4°C
Hence, if TAMBIENT = +25°C, the DC/DC converter case
temperature will be approximately 85°C if no heat sink or
air flow is provided.
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AHF2815T Series
AHF2815T Case Outlines
Standard
0 .2 0 5
(5 .2 1 )
0 .0 3 0 d ia ., 8 p in s
(0 .7 6 0 )
8
1
0 .9 0 5
(2 2 .9 9 )
2
7
6
0 .5 0 5
(1 2 .8 3 )
1 .1 0 5
(2 8 .0 7 )
3
4
0 .7 0 5
(1 7 .9 1 )
1 .4 5 0
(3 6 .8 3 )
5
0 .8 0 0
(2 0 .3 2 )
1 .1 2 0
(2 8 .4 5 )
0 .0 9 0 R T y p
(2 .2 9 0 )
0 .2 6 0
(6 .6 0 0 )
0 .3 3 0
(8 .3 8 0 )
MAX
Flanged
AHF2815T Pin Designation
Pin No.
Designation
1
Enable Input
Part Numbering
AHF 28 15 T F / CH
M ode l
2
4
+Dual Output
3
Output Return
4
-Dual Output
5
+5V Output
6
Case Ground
7
Input Return
8
Positive Input
S cree nin g
Input V oltage
28 = 28V N o m ina l
O utput V oltage
15 = 5 V ,±1 5V
–
, ES, H B, CH
P ackag e O ption s
O utputs
F = F la nge
O m it fo r S tan dard
T = T riple
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AHF2815T Series
Available Screening Levels and Process Variations for AHF2815T Series
Requirement
Temperature
Range
Element
Evaluation
Internal Visual
Temperature
Cycle
Constant
Acceleration
Burn-in
Final Electrical
(Group A)
Seal, Fine &
Gross
External
Visual
MIL-STD-883
Method
No
Suffix
-20 to +85°C
ES
Suffix
-55°C to +125°C
HB
Suffix
-55°C to +125°C
CH
Suffix
-55°C to +125°C
MIL-PRF-38534
∗
2017
1010
2001
Yes
Cond B
Yes
Cond C
Yes
Cond C
500g
Cond A
Cond A
1015
MIL-PRF38534
Specification
1014
48hrs @ 85°C
25°C
48hrs @ 125°C
25°C
160hrs @ 125°C
-55, +25, +125°C
160hrs @ 125°C
-55, +25, +125°C
Cond A
Cond A, C
Cond A, C
Cond A, C
2009
∗
Yes
Yes
Yes
* Per Commercial Standards
Available Standard Military Drawing (SMD) Cross Reference
Standardized
Military Drawing
Pin
5962-9462301
Vendor
CAGE
Code
52467
Vendor
Similar
Pin
AHF2815T
WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, Tel: (310) 322 3331
ADVANCED ANALOG: 2270 Martin Av., Santa Clara, California 95050, Tel: (408) 727-0500
Visit us at www.irf.com for sales contact information.
Data and specifications subject to change without notice. 10/02
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