Microchip Technology ARD00386 Data Sheet

 2011 Microchip Technology Inc.

DS22234B-page 1

• Up to 96% Typical Efficiency

• 800 mA Typical Peak Input Current Limit:

- I

OUT 

> 100 mA @ 1.2V V

IN

, 3.3V V

OUT

- I

OUT 

> 350 mA @ 2.4V V

IN

, 3.3V V

OUT

- I

OUT

 > 350 mA @ 3.3V V

IN

, 5.0V V

OUT

• Low Start-up Voltage: 0.65V, typical 3.3V V

OUT 

@ 1 mA

• Low Operating Input Voltage: 0.35V, typical 

3.3V

OUT

 @ 1 mA

• Adjustable Output Voltage Range: 2.0V to 5.5V

• Maximum Input Voltage 

 V

OUT

 < 5.5V

• Automatic PFM/PWM Operation (MCP1640C):

- PFM Operation Disabled (MCP1640B/D)

- PWM Operation: 500 kHz

• Low Device Quiescent Current: 19 µA, typical 

PFM Mode

• Internal Synchronous Rectifier

• Internal Compensation

• Inrush Current Limiting and Internal Soft-Start

• Selectable, Logic Controlled, Shutdown States:

- True Load Disconnect Option (MCP1640B)

- Input to Output Bypass Option (MCP1640C/D)

• Shutdown Current (All States): < 1 µA

• Low Noise, Anti-Ringing Control

• Overtemperature Protection

• Available Packages:

- 6-Lead SOT23

- 8-Lead 2x3 DFN

• One, Two and Three Cell Alkaline and NiMH/NiCd 

Portable Products

• Single Cell Li-Ion to 5V Converters

• Li Coin Cell Powered Devices

• Personal Medical Products

• Wireless Sensors

• Handheld Instruments

• GPS Receivers

• Bluetooth Headsets

• +3.3V to +5.0V Distributed Power Supply

The MCP1640/B/C/D is a compact, high-efficiency,
fixed frequency, synchronous step-up DC-DC con-
verter. It provides an easy-to-use power supply solution
for applications powered by either one-cell, two-cell, or
three-cell alkaline, NiCd, NiMH, one-cell Li-Ion or
Li-Polymer batteries.

Low-voltage technology allows the regulator to start up
without high inrush current or output voltage overshoot
from a low 0.65V input. High efficiency is accomplished
by integrating the low resistance N-Channel Boost
switch and synchronous P-Channel switch. All
compensation and protection circuitry are integrated to
minimize external components. For standby
applications, the MCP1640 operates and consumes
only 19 µA while operating at no load, and provides a
true disconnect from input to output while shut down
(EN = GND). Additional device options are available
that operate in PWM-only mode and connect input to
output bypass while shut down.

A “true” load disconnect mode provides input to output
isolation while disabled by removing the normal boost
regulator diode path from input to output. A Bypass
mode option connects the input to the output using the
integrated low resistance P-Channel MOSFET, which
provides a low bias keep-alive voltage for circuits
operating in Deep Sleep mode. Both options consume
less than 1 µA of input current.

Output voltage is set by a small external resistor
divider. Two package options are available, 6-Lead
SOT23 and 8-Lead 2x3 DFN.

8-Lead 2x3 DFN*

P

GND

S

GND

EN

V

OUTS

V

OUTP

1

2

3

4

8

7

6

5 SW

V

IN

V

FB

EP

9

4

1

2

3

6 V

IN

V

FB

SW

GND

EN

5 V

OUT

6-Lead SOT23

* Includes Exposed Thermal Pad (EP); see 

.