AFL2805DZ/CHPBF [INFINEON]
DC-DC Regulated Power Supply Module, 2 Output, 80W, Hybrid, HERMETIC SEALED PACKAGE-12;
| 型号： | AFL2805DZ/CHPBF |
| 厂家： | 
Infineon |
| 描述： | DC-DC Regulated Power Supply Module, 2 Output, 80W, Hybrid, HERMETIC SEALED PACKAGE-12 输出元件 |
| 文件： | 总11页 (文件大小：123K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PD - 94458B
AFL28XXD SERIES
28V Input, Dual Output
ADVANCED ANALOG
HIGH RELIABILITY
HYBRID DC/DC CONVERTERS
Description
The AFL Series of DC/DC converters feature high power
density with no derating over the full military tempera-
ture range. This series is offered as part of a complete
family of converters providing single and dual output
voltages and operating from nominal +28 or +270 volt
inputs with output power ranging from 80 to 120 watts.
For applications requiring higher output power, indi-
vidual converters can be operated in parallel. The inter-
nal current sharing circuits assure equal current distri-
bution among the paralleled converters. This series in-
corporates Advanced Analog’s proprietary magnetic
pulse feedback technology providing optimum dynamic
line and load regulation response. This feedback sys-
tem samples the output voltage at the pulse width modu-
lator fixed clock frequency, nominally 550 KHz. Multiple
converters can be synchronized to a system clock in the
500 KHz to 700 KHz range or to the synchronization
output of one converter. Undervoltage lockout, primary
and secondary referenced inhibit, soft-start and load
fault protection are provided on all models.
AFL
Features
n 16 To 40 Volt Input Range
±5, ±12, and ±15 Volts Outputs Available
n
3
n High Power Density - up to 70 W / in
n Up To 100 Watt Output Power
n Parallel Operation with Power 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 Output Voltage Trim
n Primary and Secondary Referenced
Inhibit Functions
n Line Rejection > 40 dB - DC to 50KHz
n External Synchronization Port
n Fault Tolerant Design
n Single Output Versions Available
n Standard Military Drawings Available
These converters are hermetically packaged in two en-
closure variations, utilizing copper core pins to mini-
mize resistive DC losses. Three lead styles are avail-
able, each fabricated with Advanced Analog’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 available in four screening
grades to satisfy a wide range of requirements. The CH
grade is fully compliant to the requirements of MIL-H-
38534 for class H. The HB grade is processed and
screened to the class H requirement, but may not nec-
essarily meet all of the other MIL-PRF-38534 require-
ments, 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 mili-
tary temperature range without output power deration.
Two grades with more limited screening are also avail-
able for use in less demanding applications. Varia-
tions in electrical, mechanical and screening can
be accommodated. Contact Advanced Analog for
special requirements.
www.irf.com
1
09/11/02
AFL28XXD Series
Specifications
ABSOLUTE MAXIMUM RATINGS
Input Voltage
-0.5V to 50V
Soldering Temperature
Case Temperature
300°C for 10 seconds
Operating
Storage
-55°C to +125°C
-65°C to +135°C
Static Characteristics -55°C < TCASE < +125°C, 16V< VIN < 40V unless otherwise specified.
Group A
Parameter
INPUT VOLTAGE
Subgroups
Test Conditions
Min
Nom
Max
Unit
Note 6
16
28
40
V
OUTPUT VOLTAGE
V
IN
= 28 Volts, 100% Load
AFL2805D
AFL2812D
AFL2815D
AFL2805D
AFL2812D
AFL2815D
1
1
4.95
-5.05
5.00
-5.00
5.05
-4.95
V
V
Positive Output
Negative Output
Positive Output
Negative Output
1
1
11.88
-12.12
12.00
-12.00
12.12
-11.88
V
V
Positive Output
Negative Output
1
1
14.85
-15.15
15.00
-15.00
15.15
-14.85
V
V
Positive Output
Negative Output
2, 3
2, 3
4.90
-5.10
5.10
-4.90
V
V
Positive Output
Negative Output
2, 3
2, 3
11.76
-12.24
12.24
-11.76
V
V
Positive Output
Negative Output
2, 3
2, 3
14.70
-15.30
15.30
-14.70
V
V
OUTPUT CURRENT
OUTPUT POWER
V
IN
= 16, 28, 40 Volts - Notes 6, 11
Either Output
AFL2805D
AFL2812D
AFL2815D
12.8
6.4
A
A
A
Either Output
Either Output
5.3
Total of Both Outputs. Notes 6,11
AFL2805D
AFL2812D
AFL2815D
80
96
W
W
W
100
Each Output Note 1
10,000
MAXIMUM CAPACITIVE LOAD
µfd
V
IN
= 28 Volts, 100% Load - Notes 1, 6
OUTPUT VOLTAGE
TEMPERATURE COEFFICIENT
-0.015
+0.015
%/°C
OUTPUT VOLTAGE REGULATION
Note 10
-0.5
-1.0
+0.5
+1.0
%
%
Line
Load
1, 2, 3
1, 2, 3
No Load, 50% Load, 100% Load
V
= 16, 28, 40 Volts.
IN
Cross
V
IN
= 16, 28, 40 Volts. Note 12
AFL2805D
1, 2, 3
1, 2, 3
1, 2, 3
Positive Output
Negative Output
-1.0
-8.0
+1.0
+8.0
%
%
AFL2812D
AFL2815D
Positive Output
Negative Output
-1.0
-5.0
+1.0
+5.0
%
%
Positive Output
Negative Output
-1.0
-5.0
+1.0
+5.0
%
%
For Notes to Specifications, refer to page 4
2
www.irf.com
AFL28XXD Series
Static Characteristics (Continued)
Group A
Parameter
Subgroups
Test Conditions
Min
Nom
Max
Unit
OUTPUT RIPPLE VOLTAGE
V
= 16, 28, 40 Volts, 100% Load,
IN
BW = 10MHz
AFL2805D
1, 2, 3
1, 2, 3
1, 2, 3
60
80
80
mV
mV
mV
pp
pp
pp
AFL2812D
AFL2815D
V
= 28 Volts
INPUT CURRENT
IN
1
2, 3
80.0
100.0
mA
mA
No Load
Inhibit 1
I
= 0
OUT
1, 2, 3
5.0
mA
Pin 4 Shorted to Pin 2
Pin 12 Shorted to Pin 8
Inhibit 2
1, 2, 3
1, 2, 3
50.0
30.0
mA
mA
AFL2805D
AFL2812D, 15D
INPUT RIPPLE CURRENT
AFL2805D
V
= 28 Volts, 100% Load
IN
1, 2, 3
1, 2, 3
1, 2, 3
60
60
60
mA
pp
pp
pp
AFL2812D
AFL2815D
mA
mA
V
= 90% V
, Equal current on
NOM
CURRENT LIMIT POINT
OUT
Expressed as a percentage
of Full Rated Load
positive and negative outputs. Note 5
1
2
3
115
105
125
125
115
140
%
%
%
LOAD FAULT POWER DISSIPATION
VIN = 28 Volts
1, 2, 3
33
W
Overload or Short Circuit
EFFICIENCY
AFL2805D
AFL2812D
AFL2815D
VIN = 28 Volts, 100% Load
1, 2, 3
1, 2, 3
1, 2, 3
78
82
81
81
84
85
%
%
%
ENABLE INPUTS (Inhibit Function)
Converter Off
1, 2, 3
1, 2, 3
Logical Low on Pin 4 or Pin 12
Note 1
Logical High on Pin 4 and Pin 12 - Note 9 2.0
Note 1
-0.5
0.8
100
50
V
µA
V
Sink Current
Converter On
Sink Current
100
µA
SWITCHING FREQUENCY
1, 2, 3
500
550
600
KHz
SYNCHRONIZATION INPUT
Frequency Range
1, 2, 3
1, 2, 3
1, 2, 3
500
2.0
-0.5
700
10
0.8
100
80
KHz
V
V
nSec
%
Pulse Amplitude, Hi
Pulse Amplitude, Lo
Pulse Rise Time
Note 1
Note 1
20
Pulse Duty Cycle
1
Input to Output or Any Pin to Case
(except Pin 3). Test @ 500VDC
100
ISOLATION
MΩ
DEVICE WEIGHT
MTBF
Slight Variations with Case Style
85
gms
MIL-HDBK-217F, AIF @ T = 70°C
C
300
KHrs
For Notes to Specifications, refer to page 4
www.irf.com
3
AFL28XXD Series
Dynamic Characteristics -55°C < TCASE < +125°C, VIN=28V unless otherwise specified.
Group A
Parameter
Subgroups
Test Conditions
Min
Nom
Max
Unit
LOAD TRANSIENT RESPONSE
Note 2, 8
AFL2805D
Either Output
Amplitude
Recovery
4, 5, 6
4, 5, 6
Load Step 50%
100%
-450
-450
450
200
mV
µSec
4, 5, 6
4, 5, 6
Load Step 10%
50%
50%
10%
450
200
400
mV
µSec
µSec
Amplitude
Recovery
10%
50%
4, 5, 6
4, 5, 6
Load Step 50%
100%
-750
-750
750
200
mV
µSec
AFL2812D
Either Output
Amplitude
Recovery
4, 5, 6
4, 5, 6
750
200
400
mV
µSec
µSec
Amplitude
Recovery
Load Step 10%
50%
50%
10%
10%
50%
4, 5, 6
4, 5, 6
-750
-750
750
200
mV
µSec
AFL2815D
Either Output
Amplitude
Recovery
Load Step 50%
100%
4, 5, 6
4, 5, 6
750
200
400
mV
µSec
µSec
Amplitude
Recovery
Load Step 10%
50%
50%
10%
10%
50%
LINE TRANSIENT RESPONSE
Note 1, 2, 3
V
Step = 16
40 Volts
Amplitude
Recovery
-500
500
500
mV
µSec
IN
V
= 16, 28, 40 Volts. Note 4
TURN-ON CHARACTERSTICS
IN
4, 5, 6
4, 5, 6
Enable 1, 2 on. (Pins 4, 12 high or
open)
250
10
mV
mSec
Overshoot
Delay
0
4
LOAD FAULT RECOVERY
LINE REJECTION
Same as Turn On Characteristics.
MIL-STD-461D, CS101, 30Hz to
40
50
dB
50KHz
Note 1
Notes to Specifications:
1. Parameters not 100% tested but are guaranteed to the limits specified in the table.
2. Recovery time is measured from the initiation of the transient to where V
at 50% load.
has returned to within ±1% of V
out
out
3. Line transient transition time ≥ 100 µSec.
4. Turn-on delay is measured with an input voltage rise time of between 100 and 500 volts per millisecond.
5. Current limit point is that condition of excess load causing output voltage to drop to 90% of nominal.
6. Parameter verified as part of another test.
7. All electrical tests are performed with the remote sense leads connected to the output leads at the load.
8. Load transient transition time ≥ 10 µSec.
9. Enable inputs internally pulled high. Nominal open circuit voltage ≈ 4.0VDC.
10. Load current split equally between +V
out
and -V .
out
11. Output load must be distributed so that a minimum of 20% of the total output power is being provided by one of
the outputs.
12. Cross regulation measured with load on tested output at 20% of maximum load while changing the load on
other output from 20% to 80%.
4
www.irf.com
AFL28XXD Series
AFL28XXD Circuit Description
Figure I. AFL Dual Output Block Diagram
Input
Filter
Output
Filter
1
4
+ Output
DC Input
Enable 1
7
Current
Sense
Primary
Bias Supply
Output Return
-Output
8
9
Output
Filter
Sync Output
5
Share
Amplifier
Control
Share
11
Error
Amp
& Ref
Sync Input
Case
6
3
2
12 Enable 2
Trim
10
Input Return
series can be initiated by simply applying an input voltage to
pins 1 and 2 and connecting the appropriate loads between
pins 7, 8, and 9. As is the case with any high power density
converter, operation should not be initiated before secure
attachment to an appropriate heat dissipator. (See Thermal
Considerations, page 7) Additional application information
is provided in the paragraphs following.
Circuit Operation and Application Information
The AFL series of converters employ a forward switched
mode converter topology. (refer to the block diagram in
Figure I.) Operation of the device is initiated when a DC
voltage whose magnitude is within the specified input volt-
age 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. A power
MOSFET is used to chop the DC input voltage into a high
frequency square wave, applying this chopped voltage to
the power transformer at the nominal converter switching
frequency. By maintaining a DC voltage within specified
operating range at the input, continuous generation of the
bias voltage is assured.
Inhibiting Converter Output
As an alternative to application and removal of the DC volt-
age 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 refer-
enced 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 nor-
mal converter operation. When their use is desired, a logi-
cal “low” on either port will shut the converter down.
The switched voltage impressed on the secondary output
transformer windings is rectified and filtered to provide the
positive and negative converter output voltages. An error
amplifier on the secondary side compares the positive out-
put 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 control section of the converter varying the pulse width
of the square wave signal driving the MOSFETs, narrowing
the pulse width if the output voltage is too high and widening
it if it is too low. These pulse width variations provide the
necessary corrections to regulate the magnitude of output
voltage within its’ specified limits.
Figure II. Enable Input Equivalent Circuit
+5.6V
100K
1N4148
Pin 4 or
Pin 12
Disable
200K
Because the primary portion of the circuit is coupled to the
secondary side with magnetic elements, full isolation from
input to output is maintained.
2N3904
220K
Although incorporating several sophisticated and useful
ancilliary features, basic operation of the AFL28XXD series
Pin 2 or
Pin 8
www.irf.com
5
AFL28XXD Series
Internally, these ports differ slightly in their function. In use,
a low on Enable 1 completely shuts down all circuits in the
converter, while a low on Enable 2 shuts down the second-
ary side while altering the controller duty cycle to near zero.
Externally, the use of either port is transparent to the user
save for minor differences in idle current. (See specification
table).
level of +2.0 volts. The sync output of another converter
which has been designated as the master oscillator pro-
vides a convenient frequency source for this mode of op-
eration. When external synchronization is not indicted, the
sync in pin should be left open (unconnected )thereby per-
mitting the converter to operate at its’ own internally set
frequency.
Synchronization of Multiple Converters
The sync output signal is a continuous pulse train set at
550 ±50 KHz, with a duty cycle of 15 ±5%. This signal is
referenced to the input return and has been tailored to be
compatible with the AFL sync input port. Transition times
are less than 100 ns and the low level output impedance is
less than 50 ohms. This signal is active when the DC input
voltage is within the specified operating range and the con-
verter is not inhibited. This synch output has adequate
drive reserve to synchronize at least five additional con-
verters. A typical synchronization connection option is il-
lustrated in Figure III.
When operating multiple converters, system requirements
often dictate operation of the converters at a common fre-
quency. To accommodate this requirement, the AFL series
converters provide both a synchronization input and out-
put.
The sync input port permits synchronization of an AFL co-
nverter to any compatible external frequency source oper-
ating between 500 and 700 KHz. This input signal should
be referenced to the input return and have a 10% to 90%
duty cycle. Compatibility requires transition times less th an
100 ns, maximum low level of +0.8 volts and a minimum high
Figure III. Preferred Connection for Parallel Operation
1
12
Enable
2
Power
Input
Vin
Rtn
Share
Trim
Case
Enable
AFL
AFL
1
-
Output
Return
Output
Sync Out
Sync In
+
7
6
1
Optional
Synchronization
Connection
Share Bus
12
Enable
2
Vin
Rtn
Share
Trim
Case
Enable
1
-
Output
Return
Output
to Negative Load
to Positive Load
Sync Out
Sync In
+
7
6
1
12
Enable
2
Vin
Rtn
Share
Trim
Case
AFL
Enable
1
-
Output
Return
Output
Sync Out
Sync In
+
6
7
(Other Converters)
ture of the AFL series operating in the parallel mode is that
in addition to sharing the current, the stress induced by
temperature will also be shared. Thus if one member of a
paralleled set is operating at a higher case temperature, the
current it provides to the load will be reduced as compensa-
tion for the temperature induced stress on that device.
Parallel Operation-Current and Stress Sharing
Figure III. illustrates the preferred connection scheme for
operation of a set of AFL converters with outputs operating
in parallel. Use of this connection permits equal current shar-
ing among the members of a set whose load current ex-
ceeds the capacity of an individual AFL. An important fea-
6
www.irf.com
AFL28XXD Series
When operating in the shared mode, it is important that A conservative aid to estimating the total heat sink surface
symmetry of connection be maintained as an assurance of area (AHEAT SINK) required to set the maximum case temp-
optimum load sharing performance. Thus, converter out- erature rise (∆T) above ambient temperature is given by
puts should be connected to the load with equal lengths of the following expression:
wire of the same gauge and should be connected to a com-
mon physical point, preferably at the load along with the
−1.43
∆T
converter output and return leads. All converters in a par-
alleled set must have their share pins connected together.
This arrangement is diagrammatically illustrated in Figure
III. showing the output and return pins connected at a star
point which is located close as possible to the load.
A
HEAT SINK
≈
− 3.0
0.85
80P
where
∆T = Case temperature rise above ambient
As a consequence of the topology utilized in the current
sharing circuit, the share pin may be used for other func-
tions. In applications requiring only a single converter, the
voltage appearing on the share pin may be used as a “total
current monitor”. The share pin open circuit voltage is nomi-
nally +1.00v at no load and increases linearly with increas-
ing total output current to +2.20v at full load. Note that the
current we refer to here is the total output current, that is,
the sum of the positive and negative outout currents.
1
P = Device dissipation in Watts = POUT
Eff
−1
As an example, assume that it is desired to operate an
AFL2815D in a still air environment where the ambient tem-
perature is held to a constant +25°C while holding the case
temperature at TC ≤ +85°C; then case temperature rise is
Thermal Considerations
∆T = 85 - 25 = 60°C
Because of the incorporation of many innovative techno-
logical concepts, the AFL series of converters is capable of
providing very high output power from a package of very
small volume. These magnitudes of power density can only
be obtained by combining high circuit efficiency with effec-
tive methods of heat removal from the die junctions. This
requirement has been effectively addressed inside the de-
vice; but when operating at maximum loads, a significant
amount of heat will be generated and this heat must be
conducted away from the case. To maintain the case tem-
perature at or below the specified maximum of 125°C, this
heat must be transferred by conduction to an appropriate
heat dissipater held in intimate contact with the converter
base-plate.
From the Specification Table, the worst case full load effi-
ciency for AFL2815D is 83% at 100 watts: thus, power dis-
sipation at full load is given by
1
P = 100•
−1 = 100• 0.205 = 20.5W
(
)
.83
and the required heat sink area is
1.43
−
60
A
HEAT SINK
=
− 3.0 = 56.3 in2
Since the effectiveness of this heat transfer is dependent
on the intimacy of the baseplate/heatsink interface, it is
strongly recommended that a high thermal conductivity heat
transferring medium is inserted between the baseplate and
heatsink. The material most frequently utilized at the fac-
tory during all testing and burn-in processes is sold under
80• 20.50.85
Thus, a total heat sink surface area (including fins, if any) of
2
56 in in this example, would limit case rise to 60°C above
ambient. A flat aluminum plate, 0.25" thick and of approxi-
1
the trade name of Sil-Pad 400 . This particular product is
2
mate dimension 4" by 7" (28 in per side) would suffice for
an insulator but electrically conductive versions are also
available. Use of these materials assures maximum sur-
face contact with the heat dissipater thereby compensating
for any minor surface variations. While other available types
of heat conductive materials and thermal compounds pro-
vide similar effectiveness, these alternatives are often less
convenient and can be somewhat messy to use.
this application in a still air environment. Note that to meet
the criteria in this example, both sides of the plate require
unrestricted exposure to the +25°C ambient air.
1
Sil-Pad is a registered Trade Mark of Bergquist, Minneapolis, MN
www.irf.com
7
AFL28XXD Series
Input Filter
Table 1. Output Voltage Trim Values and Limits
The AFL28XXD series converters incorporate a two stage
LC input filter whose elements dominate the input load im-
pedance characteristic during the turn-on sequence. The
input circuit is as shown in Figure IV.
AFL2805D
AFL2812D
AFL2815D
Vout Radj
Vout Radj
Vout Radj
5.5
5.4
0
12.5
12.4
12.3
12.2
12.1
12.0
11.7
11.3
10.8
10.6
10.417
0
15.5
15.4
15.3
15.2
15.1
15.0
14.6
14.0
13.5
13.0
12.917
0
12.5K
33.3K
75K
200K
∞
47.5K
127K
285K
760K
∞
62.5K
167K
375K
1.0M
∞
Figure IV. Input Filter Circuit
5.3
5.2
5.1
900nH
130nH
5.0
Pin 1
Pin 2
4.9
190K
65K
23K
2.5K
0
975K
288K
72.9K
29.9K
0
1.2M
325K
117K
12.5K
0
4.8
4.7
6 µfd
11.2 µfd
4.6
4.583
Note that the nominal magnitude of output voltage resides in
the middle of the table and the corresponding resistor value
is set to ∞. To set the magnitude greater than nominal, the
adjust resistor is connected to output return. To set the
magnitude less than nominal, the adjust resistor is con-
nected to the positive output. (Refer to Figure V.)
Undervoltage Lockout
A minimum voltage is required at the input of the converter
to initiate operation. This voltage is set to 14.0 ± 0.5 volts. To
preclude the possibility of noise or other variations at the
input falsely initiating and halting converter operation, a hys-
teresis of approximately 1.0 volts is incorporated in this
circuit. Thus if the input voltage droops to 13.0 ± 0.5 volts,
the converter will shut down and remain inoperative until the
input voltage returns to ≈14.0 volts.
For output voltage settings that are within the limits, but
between those listed in Table I, it is suggested that the
resistor values be determined empirically by selection or by
use of a variable resistor. The value thus determined can
then be replaced with a good quality fixed resistor for per-
manent installation.
OutputVoltage Adjust
When use of this adjust feature is elected, the user should
be aware that the temperature performance of the con-
verter output voltage will be affected by the temperature
performance of the resistor selected as the adjustment
element and therefore, is advised to employ resistors with a
tight temperature coefficient of resistance.
By use of the trim pin (10), the magnitude of output voltages
can be adjusted over a limited range in either a positive or
negative direction. Connecting a resistor between the trim
pin and either the output return or the positive output will
raise or lower the magnitude of output voltages. The span
of output voltage adjustment is restricted to the limits shown
in Table I.
General Application Information
The AFL28XXD series of converters are capable of pro-
viding large transient currents to user loads on demand.
Because the nominal input voltage range in this series is
relatively low, the resulting input current demands will be
correspondingly large. It is important therefore, that the line
impedance be kept very low to prevent steady state and
transient input currents from degrading the supply voltage
between the voltage source and the converter input. In
applications requiring high static currents and large tran-
sients, it is recommended that the input leads be made of
adequate size to minimize resistive losses, and that a good
quality capacitor of approximately100µfd be connected di-
rectly across the input terminals to assure an adequately
low impedance at the input terminals. Table I relates nomi-
nal resistance values and selected wire sizes.
Figure V. Connection for VOUT Adjustment
12
Enable
2
Share
Trim
RADJ
-
+
AFL28xxD
-
Vout
Return
Vout
To
Loads
+
7
Connect Radj to + to increase, - to decrease
8
www.irf.com
AFL28XXD Series
Table 1. Nominal Resistance of Cu Wire
Another potential problem resulting from parasitically in-
duced voltage drop on the input lines is with regard to the
operation of the enable 1 port. The minimum and maxi-
mum operating levels required to operate this port are
specified with respect to the input common return line at
the converter. If a logic signal is generated with respect to
a ‘common’ that is distant from the converter, the effects of
the voltage drop over the return line must be considered
when establishing the worst case TTL switching levels.
These drops will effectively impart a shift to the logic lev-
els. In Figure VI, it can be seen that referred to system
Wire Size, AWG
Resistance per ft
24 Ga
22 Ga
20 Ga
18 Ga
16 Ga
14 Ga
12 Ga
25.7 mΩ
16.2 mΩ
10.1 mΩ
6.4 mΩ
4.0 mΩ
2.5 mΩ
1.6 mΩ
ground, the voltage on the input return pin is given by
As an example of the effects of parasitic resistance, con-
sider an AFL2815D operating at full power of 100 W. From
the specification sheet, this device has a minimum effi-
ciency of 83% which represents an input power of more
than 120 W. If we consider the case where line voltage is at
its’ minimum of 16 volts, the steady state input current
necessary for this example will be slightly greater than 7.5
amperes. If this device were connected to a voltage source
with 10 feet of 20 gauge wire, the round trip (input and
return) would result in 0.2 Ω of resistance and 1.5 volts of
drop from the source to the converter. To assure 16 volts
at the input, a source closer to 18 volts would be required.
In applications using the paralleling option, this drop will be
multiplied by the number of paralleled devices. By choos-
ing 14 or 16 gauge wire in this example, the parasitic resis-
tance and resulting voltage drop will be reduced to 25% or
eRtn = IRtn • RP
Therefore, the logic signal level generated in the system
must be capable of a TTL logic high plus sufficient addi-
tional amplitude to overcome eRtn. When the converter is
inhibited, IRtn diminishes to near zero and eRtn will then be at
system ground.
Incorporation of a 100 µfd capacitor at the input terminals
is recommended as compensation for the dynamic ef-
fects of the parasitic resistance of the input cable reacting
with the complex impedance of the converter input, and to
provide an energy reservoir for transient input current
requirements.
31% of that with 20 gauge wire.
Figure VI. Problems of Parasitic Resistance in input Leads
Rp
Rp
Iin
Vin
100
µfd
e s o u r c e
Rtn
e Rt n
IRt n
Case
Enable 1
Sync Out
Sync In
System Ground
www.irf.com
9
AFL28XXD Series
AFL28XXD Case Outlines
Case X
Case W
Pin Variation of Case Y
3.000
ø
0.128
2.760
0.050
0.050
0.250
0.250
1.000
1.000
Ref
1.260 1.500
0.200 Typ
Non-cum
Pin
ø
0.040
Pin
0.040
0.220
ø
2.500
0.220
0.525
2.800
2.975 max
0.238 max
0.42
*per
0.380
Max
0.380
Max
Case Y
Case Z
Pin Variation of Case Y
1.150
0.300
ø
0.140
0.25 typ
0.050
0.050
0.250
0.250
1.000
Ref
1.500 1.750 2.00
1.000
Ref
0.200 Typ
Non-cum
Pin
ø
0.040
Pin
ø
0.040
0.220
0.220
1.750
2.500
0.375
0.36
2.800
2.975 max
0.525
0.238 max
0.380
Max
0.380
Max
Tolerances, unless otherwise specified: .XX
.XXX
=
=
±0.010
±0.005
BERYLLIAWARNING: These converters are hermetically sealed;however they contain BeO substrates and should not be ground or subjected to any other
operations including exposure to acids, which may produce Beryllium dust or fumes containing Beryllium
10
www.irf.com
AFL28XXD Series
Available Screening Levels and ProcessVariations for AFL28XXD Series.
MIL-STD-883
Method
No
ES
HB
CH
Requirement
Temperature Range
Element Evaluation
Internal Visual
Suffix
Suffix
Suffix
Suffix
-20°C to +85°C
-55°C to +125°C
-55°C to +125°C
-55°C to +125°C
MIL-PRF-38534
ü
2017
1010
2001
1015
¬
ü
Cond B
ü
Temperature Cycle
Constant Acceleration
Burn-in
Cond C
Cond C
500g
Cond A
Cond A
48hrs @ 85°C
48hrs @ 125°C
25°C
160hrs @ 125°C
160hrs @ 125°C
Final Electrical (Group A)
MIL-PRF-38534
& Specification
25°C
-55, +25, +125°C -55, +25, +125°C
Seal, Fine & Gross
External Visual
1014
2009
Cond A
Cond A, C
Cond A, C
Cond A, C
¬
ü
ü
ü
*per Commercial Standards
Part Numbering
AFL28XXD Pin Designation
AFL 28 05 D X / CH
Pin No.
Designation
Positive Input
Input Return
Case
Model
Screening
–
1
2
,
ES
Input Voltage
Case Style
W, X, Y, Z
HB, CH
28 = 28V
270 = 270V
Output Voltage
05 = 5V, 12 = 12V,
15 = 15V
Outputs
S = Single
D = Dual
3
4
Enable 1
5
Sync Output
Sync Input
AFL28XXD to Standard Military Drawing EquivalenceTable
6
7
Positive Output
Output Return
Negative Output
Output Voltage Trim
Share
AFL2805D
AFL2812D
AFL2815D
5962-9579501
5962-9579601
5962-9472401
8
9
10
11
12
Enable 2
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. 09/02
www.irf.com
11
相关型号：
AFL2805DZ/ESPBF
DC-DC Regulated Power Supply Module, 2 Output, 80W, Hybrid, HERMETIC SEALED PACKAGE-12
INFINEON
AFL2805DZ/HBPBF
DC-DC Regulated Power Supply Module, 2 Output, 80W, Hybrid, HERMETIC SEALED PACKAGE-12
INFINEON
AFL2805DZPBF
DC-DC Regulated Power Supply Module, 2 Output, 80W, Hybrid, HERMETIC SEALED PACKAGE-12
INFINEON
©2020 ICPDF网 联系我们和版权申明