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Error

Amp.

PWM

Comparator

Lx

FB

Vref

Soft Start

Each

Circuit

Inductor

L2

L1

EN/SS

Oscillator

Ramp Wave

Generator

CE

Controller

Logic

Local

Reg

Under

Voltage

Lock Out

Thermal

Shutdown

Operation

Enable

High

Side

Buffer

Low

Side

Buffer

Gate

CLAMP

Current

Limit

PFM

Current

Limit

Current

Feed

Back

Current

SENSE

PWM/PFM

Controller

Logic

Each

Circuit

GND

Power-Good

Comparator

PG

■

OPERATIONAL EXPLANATION

The XCL230/XCL231 series consists internally of a reference voltage supply with soft-start function, a ramp wave circuit, an

error amp, a PWM comparator, a High side driver FET, a Low side driver FET, a High side buffer circuit, a Low side buffer circuit,

a current sense circuit, a phase compensation (Current feedback) circuit, a current limiting circuit, an under voltage lockout

(UVLO) circuit, an internal power supply (Local Reg) circuit, a gate clamp (CLAMP) circuit and other elements.

The control method is the current mode control method for handling low ESR ceramic capacitors.