Datasheet

TPS40400

www.ti.com

SLUS930B –APRIL 2011– REVISED OCTOBER 2011

PIN FUNCTIONS (continued)

I/O DESCRIPTION

NAME NO.

Signal ground for the controller. Connect the ground of signal level circuits to this pin. Connections should be

SGND PAD - arranged so that power level currents do not flow in the pad attached to the thermal plane or in the SGND

portion of the circuit.

SMBALRT 23 O Output used to signal that PMBus host that the controller needs attention.

This is the common connection for the flying high-side FET driver and also serve as a sense line for the adaptive

SW 17 I

anti-cross-conduction circuitry

Logic level input to the oscillator inside the controller. The oscillator resets on the rising edge of a pulse train

SYNC 4 I

applied to this pin and begin a new switching cycle.

Analog input to the non inverting side of the control loop error amplifier. The error amplifier has three inputs

(voltage reference, TRACK and soft-start ramp) to it’s “+” side, and the lowest voltage applied to these three

TRACK 5 I

inputs dominate and control the output voltage of the whole converter. This pin is to allow the user to configure a

voltage divider that allows the controller output follow an external reference voltage during startup.

VDD 20 I Input power connection for the device. 3.0 V to 20 V required.

VSNS+ 9 I Non-inverting input to the unity gain remote voltage sense amplifier.

VSNS– 10 I Inverting input to the unity gain remote voltage sense amplifier.

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