PD - 94435B
AFL270XXS SERIES
270V Input, Single Output
HYBRID-HIGH RELIABILITY
DC/DC CONVERTER
Description
The AFL Series of DC/DC converters feature high power
density with no derating over the full military
temperature range. This series is offered as part of a
complete family of converters providing single and dual
output voltages and operating from nominal +28V or
+270V inputs with output power ranging from 80W to
120W. For applications requiring higher output power,
multiple converters can be operated in parallel. The
internal current sharing circuits assure equal current
distribution among the paralleled converters. This series
incorporates International Rectifier’s proprietary
magnetic pulse feedback technology providing
optimum dynamic line and load regulation response.
This feedback system samples the output voltage at
the pulse width modulator fixed clock frequency,
nominally 550KHz. Multiple converters can be
synchronized to a system clock in the 500 KHz to 700KHz
range or to the synchronization output of one converter.
Undervoltage lockout, primary and secondary
referenced inhibit, softstart and load fault protection
are provided on all models.
These converters are hermetically packaged in two
enclosure variations, utilizing copper core pins to
minimize resistive DC losses. Three lead styles are
available, each fabricated with International Rectifier’s
rugged ceramic lead-to-package seal assuring long
term hermeticity in the most harsh 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. Contact IR Santa Clara for special
requirements.
AFL
Features
n
160V To 400V Input Range
n
5V, 6V, 9V, 12V, 15V and 28V Outputs
Available
n
High Power Density - up to 84W/in3
n
Up To 120W Output Power
n
Parallel Operation with Stress and Current
Sharing
n
Low Profile (0.380") Seam Welded Package
n
Ceramic Feedthru Copper Core Pins
n
High Efficiency - to 87%
n
Full Military Temperature Range
n
Continuous Short Circuit and Overload
Protection
n
Remote Sensing Terminals
n
Primary and Secondary Referenced
Inhibit Functions
n
Line Rejection > 60dB - DC to 50KHz
n
External Synchronization Port
n
Fault Tolerant Design
n
Dual Output Versions Available
n
Standard Microcircuit Drawings Available
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1
12/18/06
AFL270XXS Series
Specifications
Absolute Maximum Ratings
Input voltage
Soldering temperature
Operating case temperature
Storage case temperature
-0.5V to +500VDC
300°C for 10 seconds
-55°C to +125°C
-65°C to +135°C
Static Characteristics
-55°C
≤
T
CASE
≤
+125°C, 160
≤
V
IN
≤
400 unless otherwise specified.
Parameter
INPUT VOLTAGE
OUTPUT VOLTAGE
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
OUTPUT CURRENT
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
MAXIMUM CAPACITIVE LOAD
OUTPUT VOLTAGE
TEMPERATURE COEFFICIENT
OUTPUT VOLTAGE REGULATION
AFL27028S
Line
All Others
Line
Load
OUTPUT RIPPLE VOLTAGE
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
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
VIN = 160, 270, 400 Volts, 100%
Load,
BW = 10MHz
Note 1
VIN = 270 Volts,100% Load - Notes1, 6
10,000
-0.015
+0.015
1
1
1
1
1
1
2, 3
2, 3
2, 3
2, 3
2, 3
2, 3
VIN = 160, 270, 400 Volts - Note 6
Group A
Subgroups
Note 6
VIN = 270 Volts, 100% Load
Test Conditions
Min
160
4.95
5.94
8.91
11.88
14.85
27.72
4.90
5.88
8.82
11.76
14.70
27.44
Nom
270
5.00
6.00
9.00
12.00
15.00
28.00
Max
400
5.05
6.06
9.09
12.12
15.15
28.28
5.10
6.12
9.18
12.24
15.30
28.56
16.0
13.5
10.0
9.0
8.0
4.0
80
81
90
108
120
112
Unit
V
V
A
OUTPUT POWER
Note 6
W
µF
%/°C
No Load, 50% Load, 100% Load
VIN = 160, 270, 400 Volts
-70.0
-10.0
-1.0
+70.0
+10.0
+1.0
30
35
40
45
50
100
mV
mV
%
mVpp
For Notes to Specifications, refer to page 4
2
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AFL270XXS Series
Static Characteristics
(Continued)
Parameter
INPUT CURRENT
No Load
Inhibit 1
Inhibit 2
INPUT RIPPLE CURRENT
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
CURRENT LIMIT POINT
Expressed as a Percentage
of Full Rated Load
LOAD FAULT POWER DISSIPATION
Overload or Short Circuit
EFFICIENCY
AFL27005S
AFL27006S
AFL27009S
AFL27012S
AFL27015S
AFL27028S
ENABLE INPUTS
(Inhibit Function)
Converter Off
Sink Current
Converter On
Sink Current
SWITCHING FREQUENCY
SYNCHRONIZATION INPUT
Frequency Range
Pulse Amplitude, Hi
Pulse Amplitude, Lo
Pulse Rise Time
Pulse Duty Cycle
ISOLATION
DEVICE WEIGHT
MTBF
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, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
V
IN
= 270 Volts
V
IN
= 270 Volts, 100% Load
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
Group A
Subgroups
Test Conditions
VIN = 270 Volts
IOUT = 0
Pin 4 Shorted to Pin 2
Pin 12 Shorted to Pin 8
VIN = 270 Volts, 100% Load
B.W. = 10MHz
Min
Nom
Max
15.00
17.00
3.00
5.00
60
60
70
70
80
80
Note 5
115
105
125
125
115
140
30
78
79
80
82
83
82
-0.5
2.0
500
500
2.0
-0.5
20
100
85
300
550
82
83
84
85
87
85
0.8
100
50
100
600
700
10
0.8
100
80
%
Unit
mA
mApp
VOUT = 90% VNOM
W
%
Logical Low, Pin 4 or Pin 12
Note 1
Logical High, Pin 4 and Pin 12 - Note 9
Note 1
V
µA
V
µA
KHz
KHz
V
V
ns
%
MΩ
g
KHrs
Note 1
Note 1
Input to Output or Any Pin to Case
(except Pin 3). Test @ 500VDC
Slight Variations with Case Style
MIL-HDBK-217F, AIF @ TC = 70°C
1
For Notes to Specifications, refer to page 4
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3
AFL270XXS Series
Dynamic Characteristics
-55°C
≤
T
CASE
≤
+125°C, V
IN
=
270 Volts unless otherwise specified.
Parameter
LOAD TRANSIENT RESPONSE
AFL27005S
Amplitude
Recovery
Amplitude
Recovery
AFL27006S
Amplitude
Recovery
Amplitude
Recovery
AFL27009S
Amplitude
Recovery
Amplitude
Recovery
AFL27012S
Amplitude
Recovery
Amplitude
Recovery
AFL27015S
Amplitude
Recovery
Amplitude
Recovery
AFL27028S
Amplitude
Recovery
Amplitude
Recovery
LINE TRANSIENT RESPONSE
Amplitude
Recovery
TURN-ON CHARACTERISTICS
Overshoot
Delay
LOAD FAULT RECOVERY
LINE REJECTION
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
4, 5, 6
Group A
Subgroups
Note 2, 8
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Load Step 50%
⇔
100%
Load Step 10%
⇔
50%
Note 1, 2, 3
VIN Step = 160
⇔
400 Volts
VIN = 160, 270, 400 Volts. Note 4
Enable 1, 2 on. (Pins 4, 12 high or
open)
Same as Turn On Characteristics.
MIL-STD-461, CS101, 30Hz to 50KHz
Note 1
60
70
dB
50
75
250
120
mV
ms
-500
500
500
mV
µs
-450
-450
-450
-450
-600
-600
-750
-750
-900
-900
-1200
-1200
450
200
450
400
450
200
450
400
600
200
600
400
750
200
750
400
900
200
900
400
1200
200
1200
400
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
mV
µs
Test Conditions
Min
Nom
Max
Unit
Notes to Specifications:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Parameters not 100% tested but are guaranteed to the limits specified in the table.
Recovery time is measured from the initiation of the transient to where VOUT has returned to within
±1.0%
of VOUT at 50% load.
Line transient transition time
≥
100µs.
Turn-on delay is measured with an input voltage rise time of between 100V and 500V per millisecond.
Current limit point is that condition of excess load causing output voltage to drop to 90% of nominal.
Parameter verified as part of another test.
All electrical tests are performed with the remote sense leads connected to the output leads at the load.
Load transient transition time
≥
10µs.
Enable inputs internally pulled high. Nominal open circuit voltage
≈
4.0VDC.
4
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AFL270XXS Series
Block Diagram
Figure 1. AFL Single Output
+ INPUT
1
INPUT
FILTER
ENABLE 1
4
PRIMARY
BIAS SUPPLY
OUTPUT
FILTER
7
10
+ OUTPUT
+ SENSE
CURRENT
SENSE
SYNC OUTPUT
5
CONTROL
SYNC INPUT
6
ERROR
AMP
& REF
SHARE
AMPLIFIER
11
12
SENSE
AMPLIFIER
SHARE
ENABLE 2
CASE
3
9
8
RETURN SENSE
OUTPUT RETURN
INPUT RETURN
2
Circuit Operation and Application Information
The AFL series of converters employ a forward switched
mode converter topology. (refer to Figure 1.) Operation of
the device is initiated when a DC voltage whose magnitude
is within the specified input limits is applied between pins 1
and 2. If pin 4 is enabled (at a logical 1 or open) the primary
bias supply will begin generating a regulated housekeeping
voltage bringing the circuitry on the primary side of the
converter to life. Two power MOSFETs used to chop the
DC input voltage into a high frequency square wave, apply
this chopped voltage to the power transformer. As this
switching is initiated, a voltage is impressed on a second
winding of the power transformer which is then rectified and
applied to the primary bias supply. When this occurs, the
input voltage is shut out and the primary bias voltage
becomes exclusively internally generated.
The switched voltage impressed on the secondary output
transformer winding is rectified and filtered to provide the
converter output voltage. An error amplifier on the secondary
side compares the output voltage to a precision reference
and generates an error signal proportional to the difference.
This error signal is magnetically coupled through the
feedback transformer into the controller section of the
converter varying the pulse width of the square wave signal
driving the MOSFETs, narrowing the width if the output
voltage is too high and widening it if it is too low.
not used, the sense leads should be connected to their
respective output terminals at the converter. Figure 3.
illustrates a typical application.
Inhibiting Converter Output (Enable)
As an alternative to application and removal of the DC
voltage to the input, the user can control the converter
output by providing TTL compatible, positive logic signals
to either of two enable pins (pin 4 or 12). The distinction
between these two signal ports is that enable 1 (pin 4) is
referenced to the input return (pin 2) while enable 2 (pin 12)
is referenced to the output return (pin 8). Thus, the user
has access to an inhibit function on either side of the isolation
barrier. Each port is internally pulled “high” so that when
not used, an open connection on both enable pins permits
normal converter operation. When their use is desired, a
logical “low” on either port will shut the converter down.
Figure 2. Enable Input Equivalent Circuit
+5.6V
100K
Pin 4 or
Pin 12
1N4148
290K
2N3904
150K
Pin 2 or
Pin 8
Disable
Remote Sensing
Connection of the
+
and
-
sense leads at a remotely located
load permits compensation for resistive voltage drop
between the converter output and the load when they are
physically separated by a significant distance. This
connection allows regulation to the placard voltage at the
point of application. When the remote sensing features is
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