 2002 Microchip Technology Inc.

DS21752A-page 1

M

MCP1252/3

Features

• Inductorless, Buck/Boost, DC/DC Converter

• Low Power: 80 µA (Typical)

• High Output Voltage Accuracy:

• 120 mA Output Current

• Wide Operating Temperature Range:

- -40°C to +85°C

• Thermal Shutdown and Short-Circuit Protection

• Uses Small Ceramic Capacitors

• Switching Frequency:

- MCP1252: 650 kHz

- MCP1253: 1 MHz

• Low Power Shutdown Mode: 0.1 µA (Typical)

• Shutdown Input Compatible with 1.8V Logic

• Selectable Output Voltage (3.3V or 5.0V) or

Adjustable Output Voltage

• Space-saving, 8-Lead MSOP

• Soft-Start Circuitry to Minimize In-Rush Current

Applications

• White LED Backlighting

• Color Display Bias

• Local 3V-to-5V Conversions

• Flash Memory Supply Voltage

• SIM Interface Supply for GSM Phones

• Smart Card Readers

• PCMCIA Local 5V Supplies

Description

The MCP1252/3 are inductorless, positive-regulated

charge pump DC/DC converters. The devices generate

a regulated fixed (3.3V or 5.0V) or adjustable output

voltage. They are specifically designed for applications

requiring low noise and high efficiency and are able to

deliver up to 120 mA output current. The devices allow

the input voltage to be lower or higher than the output

voltage, by automatically switching between buck/

boost operation.

The MCP1252 has a switching frequency of 650 kHz,

avoiding interference with sensitive IF bands. The

MCP1253 has a switching frequency of 1 MHz and

allows the use of smaller capacitors than the

MCP1252, thus saving board space and cost.

Both devices feature a power-good output that can be

used to detect out-of-regulation conditions. Extremely

low supply current and low external parts count (three

capacitors) make these devices ideal for small, battery-

powered applications. A shutdown mode is also pro-

vided for further power reduction. The MCP1252 and

MCP1253 feature thermal and short-circuit protection

and are offered in space-saving, 8-lead, MSOP

packages.

Package Types

MSOP (FIXED)

MSOP (ADJUSTABLE)

PGOOD

GND

SELECT

SHDN

C+

C-

1

2

3

4

8

7

6

5

PGOOD

GND

FB

SHDN

C+

C-

1

2

3

4

8

7

6

5

MCP1252

MCP1253

MCP1252

MCP1253

Low Noise, Positive-Regulated Charge Pump