PTH08T255W

Table 1. TERMINAL FUNCTIONS

TERMINAL

DESCRIPTION

NAME

NO.

6,7,14,15 The positive input voltage power node to the module, which is referenced to common GND.

10,11

The regulated positive power output with respect to GND.

GND

8,9,12,13

the control inputs.

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 regulator is significantly reduced. If the Inhibit pin is left

open-circuit, the module produces an output whenever a valid input source is applied.

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UVLO

This pin is also used for input undervoltage lockout (UVLO) programming. Connecting a resistor from this pin

to GND (pin 13) allows the ON threshold of the UVLO to be adjusted higher than the default value. For more

information, see the Application Information section.

A 0.05 W 1% resistor must be directly connected between this pin and pin4 (AGND) to set the output voltage

to a value higher than 3.0V. The temperature stability of the resistor should be 100 ppm/°C (or better). The

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setpoint range for the output voltage is from 3.0V to 5.25V. If left open circuit, the output voltage defaults to its

lowest value. For further information on output voltage adjustment, resistor values and equation see the

related application note.

The sense input allows the regulation circuit to compensate for voltage drop between the module and the

+ Sense

17

the module (pin 11).

The sense input allows the regulation circuit to compensate for voltage drop between the module and the

– Sense

16

load. The –Sense pin should always be connected to GND, either at the load for optimal voltage accuracy, or

at the module (pin 13).

This is an analog control input that enables the output voltage to follow an external voltage. This pin becomes

active typically 25 ms after a valid 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 module's output voltage follows the

Track

20

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 powered from the same input bus. When using this feature, a 100 k

Ω pull-up resistor

NOTE: Due to the undervoltage lockout feature, the output of the module cannot follow its own input voltage

during power up. For more information, see the related application note.

This input pin adjusts the transient response of the regulator. To activate the TurboTrans™ feature, a 1%,

50mW resistor, must be connected between this pin and pin 17 (+Sense) very close to the module. For a

given value of output capacitance, a reduction in peak output voltage deviation is achieved by utililizing this

TurboTrans™

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feature. If unused, this pin must be left open-circuit. The resistance requirement can be selected from the

TurboTrans resistor table in the Application Information section. External capacitance must never be

connected to this pin unless the TurboTrans resistor value is a short, 0

Ω.

This input pin sychronizes the switching frequency of the module to an external clock frequency. The

SmartSync feature can be used to sychronize the switching frequency of multiple modules, aiding EMI noise

SmartSync

22

suppression efforts. The external synchronization frequency must be present before a valid input voltage is

present, or before the release of inhibit control. If unused, this pin MUST be connected to GND. For more

information, please review the Application Information section.

When two modules are connected together to share load current one must be configured as the MASTER and

the other as the SLAVE. This pin is used to configure the module as either MASTER or SLAVE. To configure

CONFIG

1

the module as the MASTER, connect this pin to GND. To configure the module as the SLAVE, connect this

This pin is used when connecting two modules together to share load current. When two modules are sharing

Share

2

current the Share pin of both modules must be connected together. When not sharing current, this pin MUST

be left open (floating).

This pin is used when connecting two modules together to share load current. When two modules are sharing

Comp

3

current the Comp pin of both modules must be connected together. When not sharing current, this pin MUST

be left open (floating).

AGND

4

This pin is used when connecting two modules together to share load current. When two modules are sharing

CLKIO

5

current the CLKIO pin of both modules must be connected together. When not sharing current, this pin MUST

be left open (floating).

(1)

Denotes negative logic: Open = Normal operation, Ground = Function active

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