AHV28 Datasheet, PDF (7/9 Pages) International Rectifier – ADVANCED ANALOG HYBRID-HIGH RELIABILITY DC/DC CONVERTERS

AHV28XX Series
Application Information
Inhibit Function
Connecting the inhibit pin (Pin 2 of single and dual models,
pin 8 of triple models) to the input return (pin 10) will cause
the converter to shutdown and operate in a low power
standby mode. Power consumption in this mode is calcu-
lated by multiplying Vin times the input current inhibited,
typically 225mW at Vin equal to 28 volts. The input current
inhibited is relatively constant with changes in Vin. The open
circuit inhibit pin voltage is typically 11.5 volts and can be
conveniently driven by an open collector driver. An internal
pull-up resistor enables the user to leave this pin floating if
the inhibit function is not used in their particular application.
All models use identical inhibit internal circuits. Forcing in-
hibit pin to any voltage between 0 and 6 volts will assure the
converter is inhibited. The input current to this pin is 500µA
maximum at Vpin2 = to 0 volts. The converter can be turned
on by opening Pin 2 or forcing a voltage from 10 to 50 volts.
Inhibit pin current from 10 to 50 volts is less than ±50µA.
EMI Filter
An optional EMI filter ( AFC461) will reduce the input ripple
current to levels below the limits imposed by MIL-STD-
461 CEO3.
The output voltage of the AHV28XXS can be adjusted
upward by connecting a resistor between the Output
Adjust (Pin 3) and the Output Common (Pin 4) as shown
in Table 1.
Table 1: Output Adjustment Resistor Values
* Resistance (Ohms)
Pin 3 to 4
None
390 K
145 K
63 K
22 K
0
Output Voltage Increase (%)
5V
12V
15V
0
+1.0%
+2.0%
+3.1%
+4.1%
+5.0%
0
+1.6%
+3.2%
+4.9%
+6.5%
+7.9%
0
+1.7%
+3.4%
+5.1%
+6.8%
+8.3%
* Output Adjust (Single Output Models Only)
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