VIN (2.8V to 5.5V)

LMR70503

GND

SW

VOUT

VIN

EN

Cin

Cout

Refer to GND

D

VOUT

L

0V

1.8V

(-0.9V to -5.5V)

FB

VREF

Rb

Rt

Cff

0

30

60

90

120

150

180

30

40

50

60

70

80

LOAD (mA)

VIN = 2.8V

VIN = 3.3V

VIN = 4.0V

VIN = 5.0V

VIN = 5.5V

0

10 20 30 40 50 60 70 80 90 100

30

40

50

60

70

80

LOAD (mA)

VIN = 2.8V

VIN = 3.3V

VIN = 4.0V

VIN = 5.0V

VIN = 5.5V

LMR70503

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SNVS850A – JUNE 2012 – REVISED APRIL 2013

µSMD

Check for Samples: LMR70503

System Performance

1

FEATURES

23

•

Tiny 8-Bump Thin DSBGA Package: 0.84 mm ×

1.615 mm × 0.6 mm

•

2.8 V to 5.5 V Input Voltage Range

•

Adjustable Output Voltage: -0.9 V to -5.5 V

•

320 mA Switch Current Limit

•

500 kHz Minimum Switching Frequency

•

Ground Referred Enable Input

•

Under Voltage Lock Out (UVLO)

•

No External Compensation

•

Internal Soft Start

•

1 µA Shutdown Supply Current

•

Small Output Voltage Ripple

•

APPLICATIONS

•

General Purpose Negative Voltage Supply

•

Negative Rail / Bias Supply For Op-amp And

Data Converters

•

LCD Biasing

PERFORMANCE BENEFITS

•

Easy To Use

•

Tiny Overall Solution Size Reduces System

Cost

DESCRIPTION

The LMR70503 is a buck-boost converter with

adjustable negative output voltage in a tiny 8-bump

Typical Application Circuit

thin DSBGA package. Its unique control method is

designed to provide fast transient response, low

output noise, high efficiency, and tight regulation in

the smallest possible PCB area. The LMR70503 has

built in soft start, peak current limit, minimum

switching frequency, and Under Voltage Lock Out

(UVLO), with no external compensation required. For

ease of use, the Enable pin is referred to the IC

ground, instead of the lowest potential of the IC: the

negative output voltage.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

SIMPLE SWITCHER, WEBENCH are registered trademarks of Texas Instruments.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2012–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.