SC475AEVB datasheet(7/27 Pages) SEMTECH

7 / 27 page

SC475A

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POWER MANAGEMENT

Pin Descriptions

Pin Name

Pin Function

Switching (phase) node.

BST

Boost capacitor connection for high-side gate drive.

VCC

5V power input for the internal circuits and gate drive outputs.

Gate drive output for the low-side external MOSFET.

GND

Power ground. This is the return point for the DL driver output, and the

reference point for the ILIM and zero cross circuits.

6RTN

Return or analog ground for the FB input and FB resistor divider . Connect to

GND directly at the IC. All feedback components should connect to this ground.

Not connected internally — leave unconnected or connect to GND.

Drain of the internal MOSFET which is controlled by G0.

9FB

Feedback sense point. The FB threshold is 0.75V; the resistor divider ratio

between VOUT and FB sets the output voltage. This ratio can be modiﬁed

using the G0 input to switch a resistor in or out at D0.

VOUT

Output voltage sense point for determining On-Time.

PGOOD

Open-drain power good indicator - a high impedance indicates power is good.

An external pull-up resistor is required.

Enable input - connect EN to RTN to disable the SC475A.

ILIM

Current limit sense point — to program the current limit connect a

resistor from ILIM to LX or to a current sense resistor.

Control input for the D0 MOSFET. A logic low energizes the D0 MOSFET,

pulling D0 to ground.

Not connected internally — leave unconnected or connect to GND.

Gate drive output for the high-side external MOSFET.

TPAD

Mounting pad. Not connected internally - connect to system ground plane

through preferably one large vias or multiple smaller vias.

SC475AEVB Datenblatt(PDF) 7 Page - Semtech Corporation