MCP1642B/D
1.8A Input Current Switch, 1 MHz Low-Voltage Start-Up
Synchronous Boost Regulator
Features
• Up to 96% Typical Efficiency
• 1.8A Typical Peak Input Current Limit:
- IOUT > 175 mA @ 1.2V VIN, 3.3V VOUT
- IOUT > 600 mA @ 2.4V VIN, 3.3V VOUT
- IOUT > 800 mA @ 3.3V VIN, 5.0V VOUT
- IOUT > 1A @ VIN > 3.6V, 5.0V VOUT
• Low Start-Up Voltage: 0.65V, typical 3.3V VOUT
@ 1 mA
• Low Operating Input Voltage: 0.35V, typical 3.3V
VOUT @ 1 mA
• Output Voltage Range:
- Reference Voltage, VFB = 1.21V
- 1.8V to 5.5V for the adjustable device option
- 1.8V, 3.0V, 3.3V and 5.0V for fixed VOUT
options
• Maximum Input Voltage VOUT < 5.5V
• PWM Operation: 1 MHz
- Low Noise, Anti-Ringing Control
• Power Good Open-Drain Output
• Internal Synchronous Rectifier
• Internal Compensation
• Inrush Current Limiting and Internal Soft-Start
• Selectable, Logic-Controlled Shutdown States:
- True Load Disconnect Option (MCP1642B)
- Input-to-Output Bypass Option (MCP1642D)
• Shutdown Current (All States): 1 µA
• Overtemperature Protection
• Available Packages:
- 8-Lead MSOP
- 8-Lead 2x3 DFN
Applications
• One, Two and Three-Cell Alkaline, Lithium
Ultimate and NiMH/NiCd Portable Products
• Single-Cell Li-Ion to 5V Converters
• PIC® MCU Power
• USB Emergency Backup Charger from Batteries
• Personal Medical Products
• Wireless Sensors
• Hand-Held Instruments
• GPS Receivers
• +3.3V to +5.0V Distributed Power Supply
General Description
The MCP1642B/D devices are compact,
high-efficiency, fixed-frequency, synchronous step-up
DC-DC converters. This family of devices provides an
easy-to-use power supply solution for applications
powered by either one-cell, two-cell, or three-cell
alkaline, Ultimate Lithium, 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 voltage 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 the number of external
components. An open-drain Power Good output is
provided to indicate when the output voltage is within
10% of regulation and facilitates the interface with an
MCU. For standby applications, MCP1642B provides a
“true output disconnect” from input to output while in
shutdown (EN = GND). An additional device option
(MCP1642D) is available and connects “input to output
bypass” while in shutdown. Both options consume less
than 1 µA of input current.
For the adjustable (ADJ) device options, the output
voltage is set by a small external resistor divider. Fixed
VOUT device options do not require external divider
resistors. Two package options, 8-lead MSOP and 8-
lead 2x3 DFN, are available.
Package Types
MCP1642B/D-xx
MSOP
MCP1642B/D-xx
2x3 DFN*
EN 1
NC 2
PG 3
VOUT 4
8 VIN
EN 1
8 VIN
7 SGND NC 2 EP 7 SGND
6 PGND PG 3 9 6 PGND
5 SW VOUT 4
5 SW
MCP1642B/D-ADJ
MSOP
MCP1642B/D-ADJ
2x3 DFN*
EN 1
VFB 2
PG 3
VOUT 4
8 VIN
EN 1
8 VIN
7 SGND VFB 2 EP 7 SGND
6 PGND PG 3 9 6 PGND
5 SW VOUT 4
5 SW
* Includes Exposed Thermal Pad (EP); see Table 3-1.
2014 Microchip Technology Inc.
DS20005253A-page 1
