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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 % resistor must be directly connected

between this pin and pin 7 (GND) to set the output voltage

to a value higher than 0.8 V. The temperature stability of

the resistor should be 100 ppm/°C (or better). The set

point range for the output voltage is from 0.8 V to 3.6 V.

The resistor value required for a given output voltage

may be calculated from the following formula. If left

open circuit, the output voltage will default to its lowest

value. For further information on output voltage adjust-

ment consult the related application note.

= 10 k

Ω

0.8 V

– 2.49 k

Ω

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,

this feature does not allow the output from the module to 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, the

input may be left unconnected. For further information,

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

unused, the input may be left unconnected. For further

information, consult the related application note.

Ordering Information

10-A, 3.3-V Input Non-Isolated

Step-Down Switching Power Module

ATH10T033 Series —3.3 V Input

REVISION 00 (4DEC2003)

Input Voltage

Output Voltage

Output Current

Model Number

2.95V to 3.65V

10A

ATH10T033-9(S)(J)

Options:

“-J”

-

Through-hole Termination, Tray Packaging

“-SJ”

-

SMT Termination, Tray Packaging

“-S”

-

SMT Termination, T&R Packaging

Notes: