PM6675STR datasheet(19/53 Pages) STMICROELECTRONICS

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PM6675S

Device description

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Device description

The PM6675S combines a single high efficiency step-down controller and an independent

Low Drop-Out (LDO) linear regulator in the same package.

The switching controller section is a high-performance, pseudo-fixed frequency, Constant-

On-Time (COT) based regulator specifically designed for handling fast load transient over a

wide range of input voltages.

The switching section output can be easily set to a fixed 1.5 V voltage without additional

components or adjusted in the 0.6 V to 3.3 V range using an external resistor divider. The

Switching Mode Power Supply (SMPS) can handle different modes of operation in order to

minimize noise or power consumption, depending on the application needs. Selectable low-

consumption and low-noise modes allow the highest efficiency and a 33 kHz minimum

switching frequency respectively at light loads.

A lossless current sensing scheme, based on the Low-Side MOSFET turn-on resistance,

avoids the need for an external sensing resistor.

The input of the LDO can be either the switching section output or a lower voltage rail in

order to reduce the total power dissipation. Linear regulator stability is achieved by filtering

its output with a ceramic capacitor (20

µF or greater). The LDO linear regulator can sink and

source up to 2 Apk.

Two fixed current limit (±1 A-±2 A) can be chosen.

An active soft-end is independently performed on both the switching and the linear

regulators outputs when disabled.

PM6675STR 数据表(PDF) 19 Page - STMicroelectronics