Gate Driver

Anti

Shoot-Through

Power Save Mode

Switching Logic

+

-

Frequency

Control

FB

R1

R2

SW

GND

Soft-Start

EN

VIN

Current Limit

Detect

Undervoltage

Lockout

Bias Supply

Bandgap

Thermal

Shutdown

Negative Inductor

Current Detect

VIN

MODE

V

= 0.8 V

REF

Copyright © 2016, Texas Instruments Incorporated

8

TPS62660, TPS62665

SLVS871D – FEBRUARY 2010 – REVISED JUNE 2016

www.ti.com

Product Folder Links: TPS62660 TPS62665

Submit Documentation Feedback

Copyright © 2010–2016, Texas Instruments Incorporated

8 Detailed Description

8.1 Overview

The TPS6266x is a synchronous step-down converter typically operates at a regulated 6-MHz frequency pulse

width modulation (PWM) at moderate to heavy load currents. At light load currents, the TPS6266x converter

operates in power-save mode with pulse frequency modulation (PFM).

The converter uses a unique frequency-locked, ring-oscillating modulator to achieve best-in-class load and line

response and allows the use of tiny inductors and small ceramic input and output capacitors. At the beginning of

each switching cycle, the P-channel MOSFET switch is turned on and the inductor current ramps up rising the

output voltage until the main comparator trips, then the control logic turns off the switch.

One key advantage of the non-linear architecture is that there is no traditional feedback loop. The loop response

Although this type of operation normally results in a switching frequency that varies with input voltage and load

current, an internal frequency lock loop (FLL) holds the switching frequency constant over a large range of

operating conditions.

Combined with best in class load and line transient response characteristics, the low quiescent current of the

device (ca. 31 μA) allows to maintain high efficiency at light load, while preserving fast transient response for

applications requiring tight output regulation.

8.2 Functional Block Diagram