6

www.irf.com

AHV28XX Series

Application Information

EMI Filter

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 calculated

by multiplying Vin times the input current inhibited, typically

225mW at Vin equal to 28V. The input current inhibited is

relatively constant with changes in Vin. The open circuit

inhibit pin voltage is typically 11.5V 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 inhibit pin to any

voltage between 0V and 6V will assure the converter is

inhibited. The input current to this pin is 500

µA maximum at

Vpin2 = to 0V. The converter can be turned on by opening

Pin 2 or forcing a voltage from 10V to 50V. Inhibit pin current

from 10V to 50V is less than ± 50

µA.

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

* Output Adjust (Single Output Models Only)

Output Voltage Increase (%)

* Resistance (Ohms)

Pin 3 to 4

5V

12V

15V

None

0

0

0

390 K

+1.0%

+1.6%

+1.7%

145 K

+2.0%

+3.2%

+3.4%

63 K

+3.1%

+4.9%

+5.1%

22 K

+4.1%

+6.5%

+6.8%

0

+5.0%

+7.9%

+8.3%

Standard Microcircuit Drawing Equivalence Table

Standard Microcircuit

Vendor Cage

IR Standard

Drawing Number

Code

Part Number

5962-91773

52467

AHV2805S

5962-92112

52467

AHV2812S

5962-92113

52467

AHV2815S

5962-92114

52467

AHV2812D

5962-92115

52467

AHV2812T

5962-92116

52467

AHV2815T