- 您现在的位置：买卖IC网 > PDF目录378296 > AFL12015S (International Rectifier) HIGH RELIABILITY HYBRID DC/DC CONVERTERS PDF资料下载
参数资料
| 型号： | AFL12015S |
| 厂商： | International Rectifier |
| 英文描述： | HIGH RELIABILITY HYBRID DC/DC CONVERTERS |
| 中文描述： | 高可靠性的混合式DC / DC变换器 |
| 文件页数： | 8/11页 |
| 文件大小： | 137K |
| 代理商： | AFL12015S |
8
www.irf.com
AFL120XXS Series
R
= 100
-
-.025
adj
NOM
V
V
OUT
V
NOM
Where
V
NOM
= device nominal output voltage, and
V
OUT
= desired output voltage
Figure V. Connection for V
OUT
Adjustment
Input Filter
The AFL120XXS series converters incorporate a LC input
filter whose elements dominate the input load impedance
characteristic at turn-on. The input circuit is as shown in
Figure IV.
Undervoltage Lockout
A minimum voltage is required at the input of the converter
to initiate operation. This voltage is set to 74
±
4 volts. To
preclude the possibility of noise or other variations at the
input falsely initiating and halting converter operation, a hys-
teresis of approximately 7 volts is incorporated in this cir-
cuit. Thus if the input voltage droops to 67
±
4 volts, the
converter will shut down and remain inoperative until the
input voltage returns to
≈
74 volts.
Figure IV. Input Filter Circuit
Pin 1
Pin 2
16.8uH
0.78uF
Output Voltage Adjust
In addition to permitting close voltage regulation of remotely
located loads, it is possible to utilize the converter sense
pins to incrementally increase the output voltage over a
limited range. The adjustments made possible by this method
are intended as a means to “trim” the output to a voltage
setting for some particular application, but are not intended
to create an adjustable output converter. These output volt-
age setting variations are obtained by connecting an appro-
priate resistor value between the +sense and -sense pins
while connecting the -sense pin to the output return pin as
shown in Figure V. below. The range of adjustment and
corresponding range of resistance values can be deter-
mined by use of the following equation.
Finding a resistor value for a particular output voltage, is
simply a matter of substituting the desired output voltage
and the nominal device voltage into the equation and solv-
ing for the corresponding resistor value.
Enable 2
Share
+ Sense
- Sense
Return
+ V
out
To Load
R
ADJ
AFL120xxS
Note: R
adj
must be set
≥
500
Attempts to adjust the output voltage to a value greater than
120% of nominal should be avoided because of the poten-
tial of exceeding internal component stress ratings and sub-
sequent operation to failure. Under no circumstance should
the external setting resistor be made less than 500
. By
remaining within this specified range of values, completely
safe operation fully within normal component derating limits
is assured.
Examination of the equation relating output voltage and re-
sistor value reveals a special benefit of the circuit topology
utilized for remote sensing of output voltage in the
AFL120XXS series of converters. It is apparent that as the
resistance increases, the output voltage approaches the
nominal set value of the device. In fact the calculated limit-
ing value of output voltage as the adjusting resistor be-
comes very large is
≈
25mV above nominal device voltage.
The consequence is that if the +sense connection is unin-
tentionally broken, an AFL120XXS has a fail-safe output
voltage of Vout + 25mV, where the 25mV is independent of
the nominal output voltage. It can be further demonstrated
that in the event of both the + and - sense connections
being broken, the output will be limited to Vout + 440mV. This
440 mV is also essentially constant independent of the nomi-
nal output voltage.
相关PDF资料 |
PDF描述 |
|---|---|
| AFL12028S | HIGH RELIABILITY HYBRID DC/DC CONVERTERS |
| AFL27003R3S | HIGH RELIABILITY HYBRID DC/DC CONVERTER |
| AFL27005SW | SM RESISTOR 0402 200 OHM 1% 1/10W |
| AFL27005DW | ADVANCED ANALOG HIGH RELIABILITY HYBRID DC/DC CONVERTERS |
| AFL27005SZ | ADVANCED ANALOG HIGH RELIABILITY HYBRID DC/DC CONVERTERS |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AFL12015SW | 制造商:International Rectifier 功能描述:DC/DC CONVERTER, MINIMUM SCREENING - Bulk |
| AFL12015SW/CH | 制造商:International Rectifier 功能描述:DC/DC CONVERTER, CLASS H - Bulk |
| AFL12015SW/ES | 制造商:International Rectifier 功能描述:DC/DC CONVERTER, ENVIRONMENTAL SCREENING - Bulk |
| AFL12015SW/HB | 制造商:International Rectifier 功能描述:DC/DC CONVERTER, CLASS H EQUIVALENT, NO ELEM EVAL - Bulk |
| AFL12015SW-CH | 制造商:IRF 制造商全称:International Rectifier 功能描述:ADVANCED ANALOG HIGH RELIABILITY HYBRID DC/DC CONVERTERS |
发布紧急采购，3分钟左右您将得到回复。