North America (USA): 1-888-41-ASTEC

Europe (UK): 44(1384)842-211

Asia (HK): 852-2437-9662

Pin Descriptions

Vin:

The positive input voltage power node to the mod-

ule, which is referenced to common GND.

Vout:

The regulated positive power output with respect

to the GND node.

GND:

This is the common ground connection for the

Vin and Vout power connections. It is also the 0 VDC

reference for the control inputs.

Inhibit:

The Inhibit pin is an open-collector/drain negative

logic input that is referenced to GND. Applying a low-

level ground signal to this input disables the module’s

output and turns off the output voltage. When the Inhibit

control is active, the input current drawn by the regula-

tor is significantly reduced. If the Inhibit pin is left

open-circuit, the module will produce an output when-

ever a valid input source is applied.

Vo Adjust:

A 0.1 W, 1 % tolerance (or better) resistor

must be connected between this pin and the GND pin to

set the output voltage to the desired value. The set point

range for the output voltage is from 0.8 V to 2.5 V. The

resistor required for a given output voltage may be cal-

culated from the following formula. If left open circuit,

the module output will default to its lowest output voltage

value. For further information on the adjustment of the

output voltage consult the related application note.

= 10 k ·

0.8 V

– 2.49 k

The specification table gives the preferred resistor values

for a number of standard output voltages.

Vo Sense:

The sense input allows the regulation circuit to

compensate for voltage drop between the module and

the load. For optimal voltage accuracy Vo Sense should

be connected to Vout. It can also be left disconnected.

Track:

This is an analog control input that enables the

output voltage to follow an external voltage. This pin

becomes active typically 20 ms after the input voltage

has been applied, and allows direct control of the output

voltage from 0 V up to the nominal set-point voltage.

Within this range the output will follow the voltage at

the Track pin on a volt-for-volt basis. When the control

voltage is raised above this range, the module regulates

at its set-point voltage. The feature allows the output

voltage to rise simultaneously with other modules pow-

ered from the same input bus. If unused, the input may

be left unconnected. Note: Due to the under-voltage lockout

feature, the output of the module cannot follow its own input

voltage during power up. For more information, consult the

related application note.

Margin Down:

When this input is asserted to GND, the

output voltage is decreased by 5% from the nominal. The

input requires an open-collector (open-drain) interface.

It is not TTL compatible. A lower percent change can

be accomodated with a series resistor. If unused, this

input may be left unconnected. For further informa-

tion, consult the related application note.

Margin Up:

When this input is asserted to GND, the

output voltage is increased by 5%. The input requires an

open-collector (open-drain) interface. It is not TTL

compatible. The percent change can be reduced with a

series resistor. If ununsed, this input may be left un-

connected. For further information, consult the related

application note.

Ordering Information

ATH22T033 Series —3.3-V Input

22-A, 3.3-V Input Non-Isolated

Wide-Output Adjust Power Module

REVISION 00 (3DEC2003)

Input Voltage

Output Voltage

Output Current

Model Number

2.95V to 3.65V

22A

ATH22T033-9(S)(J)

Options:

“-J”

-

Through-hole Termination, Tray Packaging

“-SJ”

-

SMT Termination, Tray Packaging

“-S”

-

SMT Termination, T&R Packaging

Notes: