MIC5250

Micrel

June 2003

1

MIC5250

General Description

The MIC5250 is an efficient, precise dual CMOS voltage

regulator optimized for ultra-low-noise applications. The

MIC5250 offers better than 1% initial accuracy, extremely low

dropout voltage (typically 150mV at 150mA) and constant

ground current over load (typically 100

µA). The MIC5250

provides a very-low-noise output, ideal for RF applications

where quiet voltage sources are required. A noise bypass pin

is also available for further reduction of output noise.

Designed specifically for hand-held and battery-powered

devices, the MIC5250 provides TTL logic compatible enable

pins. When disabled, power consumption drops nearly to

zero.

The MIC5250 also works with low-ESR ceramic capacitors,

reducing the amount of board space necessary for power

applications, critical in hand-held wireless devices.

Key features include current limit, thermal shutdown, push-

pull outputs for faster transient response, and active clamps

to speed up device turnoff. Available in the 10-lead MSOP

(micro-shrink-outline package), the MIC5250 also offers a

range of fixed output voltages.

Typical Application

(optional)

INA

OUTA

BYPA

GNDA

OUTB

BYPB

GNDB

ENA

INB

ENB

3.3V

3.3V

MIC5250-3.3BMM

(optional)

ENABLE

SHUTDOWN

ENABLE

SHUTDOWN

ENA may be connected directly to INA.

ENB may be connected directly to INB.

GNDA and GND B may be connected to

isolated grounds or the same ground.

10

1

3

8

4

6

2

9

7

5

Dual Ultra-Low-Noise Regulator Circuit

MIC5250

Dual 150mA

OBSOLETE

Features

• Ultralow dropout—100mV @ 100mA

• Ultralow noise—30

µV(rms)

• Stability with ceramic, tantalum, or aluminum electrolytic

capacitors

• Load independent, ultralow ground current

• 150mA output current

• Current limiting

• Thermal Shutdown

• Tight load and line regulation

• “Zero” off-mode current

• Fast transient response

• TTL-Logic-controlled enable input

Applications

• Cellular phones and pagers

• Cellular accessories

• Battery-powered equipment

• Laptop, notebook, and palmtop computers

• PCMCIA V

• Consumer/personal electronics

• SMPS post-regulator/dc-to-dc modules

• High-efficiency linear power supplies

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

Ordering Information

Part Number

Voltage

Junction Temp. Range

Package

MIC5250-2.7BMM

2.7V

–40

°C to +125°C

10-lead MSOP

MIC5250-2.8BMM

2.8V

–40

°C to +125°C

10-lead MSOP

MIC5250-3.0BMM

3.0V

–40

°C to +125°C

10-lead MSOP

MIC5250-3.3BMM

3.3V

–40

°C to +125°C

10-lead MSOP

Other voltages available. Contact Micrel for details.