VIN

C1+

GND

C1-

CPOUT

Current Limit

VOUT

VFB

Negative

Bandgap

EN

LPF

2-MHz

Oscillator

Switch Array Switch

Drivers

Reference

LPF

LDO

9

LM27761

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SNVSA85B – OCTOBER 2015 – REVISED FEBRUARY 2016

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7 Detailed Description

7.1 Overview

The LM27761 regulated charge-pump voltage converter inverts a positive voltage in the range of 2.7 V to 5.5 V

to a negative voltage in the range of –1.5 V to –5 V. The negative LDO (low drop-out regulator), at the output of

the charge-pump voltage converter, allows the device to provide a very low noise output, low output-voltage

ripple, high PSRR, and low line and load transient responses. The output is externally configurable with gain-

setting resistors. The LM27761 uses four low-cost capacitors to deliver up to 250 mA of output current.

7.2 Functional Block Diagram