CALIFORNIA MICRO DEVICES

PRELIMINARY

CM3702

© 2004 California Micro Devices Corp. All rights reserved.

9/22/04

430 N. McCarthy Blvd, #100, Milpitas , CA 95035

Tel: (408) 263-3214

Fax: (408) 263-7846

www.calmicro.com

1

Micropower Low-Noise Charge-Pump and Linear Regulator

Features

• Low noise regulator with integrated charge

pump voltage-booster

• 5V output with input voltage as low as 2.8V

• Charge pump can also power external LDO

• Low noise in 20Hz to 20kHz audio band

• Up to 200mA continuous output current

• Low operating and shutdown currents

• Stable with low-ESR ceramic or tantalum

capacitors

• 10-Lead MSOP and TDFN packages

• Lead-free finishing

Applications

• 5V analog supply for audio codec in notebook

computers, PDAs, MP3 players, etc.

• 3.3V to 5V conversion in PCMCIA cards, PCI

Express Cards, other applications needing 5V

Block Diagram

Product Description

The CM3702 low-noise charge pump LDO regulator is designed to provide accurate and “clean” power to a

subsystem, e.g an audio codec, LED driver, or flash memory. The 5V output provides up to 100mA continuous

current for input voltages from 2.8V to 5.5V, and up to 200mA for a narrower range. This is accomplished with an

integrated charge pump that boosts the input voltage before feeding it to an internal LDO linear regulator. The

charge pump is designed to maintain a nominal 0.8V differential between the input and output of the LDO

regulator. This allows the LDO regulator to operate with good power supply ripple rejection across the audio band

while maintaining good power efficiency. The charge pump works with two external capacitors and operates at

250kHz, well outside the audible frequency band. In addition, separate analog and digital ground pins are

provided for the charge pump and the rest of the circuitry to eliminate ground noise feed-through from the charge

pump to the regulated output.

The CM3702 is fully protected, offering both overload current limiting and high temperature thermal shutdown.

Two enable inputs provide flexibility in powering down the device. For maximum power saving in shutdown, both

the charge pump and LDO regulator should be disabled. For applications that require the 5V output to be re-

established with minimum delay after shutdown, the charge pump can be left enabled while the regulator is

disabled. This avoids the delay that may otherwise be required for the charge pump to reach full operating

voltage after being disabled. The CMOS LDO regulator features low quiescent current even at full load, making it

very suitable for power sensitive applications.

A bandgap reference bypass pin is provided to further minimize noise by connecting an external capacitor

between this pin and ground. Another, external, regulator can be connected to the charge pump output pin Cs, if

required.

The CM3702 is available in 10-pin MSOP and TDFN packages, both with optional lead-free finishing, and are

ideal for space critical applications.

STANDARD PART ORDERING INFORMATION

Standard Finish

Lead-free Finish

Pins

Package

Ordering Part

Number

Part Marking

Ordering Part

Number

Part Marking

10

MSOP-10

CM3702-50MR

3702 50S

CM3702-50MS

3702 50

10

TDFN-10

CM3702-50DF

CM370 250DF

CM3702-50DE

CM370 250DE