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(See Note A)

FB

PGND

SW

VIN

EN

Undervoltage

Lockout

Bias supply

Control Logic

+

−

LoadComparator

1.25 MHz

Oscillator

Vref = 0.5 V

Driver

Shoot−thru

Logic

R1

R2

Soft

Start

+

−

+

−

Current limit Comparator

SkipComparator

Gm

Saw Tooth

Generator

V

I

+

−

Vcomp

S

R

+

−

Comp High

Comp Low

Comp Low 2

Comp High

Comp Low

Comp Low 2

−

+

Comparator

Compensation

Ref

Ref

PGND

VIN

GND

MODE

MODE

SW

For the Adjustable Version the FB Pin Is

Directly Connected to the Gm Amplifier

TPS62020

TPS62021

TPS62026

SLVS076C – JUNE 2003 – REVISED DECEMBER 2004

FUNCTIONAL BLOCK DIAGRAM

NOTE A: The TPS6202x has an active-high MODE pin. The TPS62021 has an active-low MODE pin.

NOTE B: The resistor network R1 and R2 is only integrated in fixed-output devices.

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