MCP1603
2.0 MHz, 500 mA Synchronous Buck Regulator
Features
General Description
• Over 90% Typical Efficiency
• Output Current Up To 500 mA
• Low Quiescent Current = 45 µA, typical
• Low Shutdown Current = 0.1 µA, typical
• Adjustable Output Voltage:
- 0.8V to 4.5V
The MCP1603 is a high efficient, fully integrated
500 mA synchronous buck regulator whose 2.7V to
5.5V input voltage range makes it ideally suited for
applications powered from 1-cell Li-Ion or 2-cell/3-cell
NiMH/NiCd batteries.
At heavy loads, the MCP1603 operates in the 2.0 MHz
fixed frequency PWM mode which provides a low
noise, low output ripple, small-size solution. When the
load is reduced to light levels, the MCP1603
automatically changes operation to a PFM mode to
minimize quiescent current draw from the battery. No
intervention is necessary for a smooth transition from
one mode to another. These two modes of operation
allow the MCP1603 to achieve the highest efficiency
over the entire operating current range.
• Fixed Output Voltage:
- 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V
• 2.0 MHz Fixed-Frequency PWM (Heavy Load)
• Automatic PWM to PFM Mode Transition
• 100% Duty Cycle Operation
• Internally Compensated
• Undervoltage Lockout (UVLO)
• Overtemperature Protection
• Space Saving Packages:
The MCP1603 is available with either an adjustable or
fixed output voltage. The available fixed output voltage
options are 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V. When a
fixed option is used, only three additional small external
components are needed to form a complete solution.
Couple this with the low profile, small-foot print
packages and the entire system solution is achieved
with minimal size.
- 5-Lead TSOT
- 8-Lead 2X3 DFN
Applications
• Cellular Telephones
• Portable Computers
• Organizers / PDAs
Additional protection features include: UVLO,
overtemperature, and overcurrent protection.
• USB Powered Devices
• Digital Cameras
• Portable Equipment
• +5V or +3.3V Distributed Systems
Package Types
5-Lead TSOT
8-Lead 2x3 DFN
LX
1
2
3
4
8
7
6
5
GND
VIN
VFB/VOUT
VIN
LX
SHDN
GND
LX
1
2
3
5
4
1
2
3
5
4
NC
SHDN
GND
NC
NC
VIN
SHDN
VFB/VOUT
VFB/VOUT
MCP1603
MCP1603L
© 2007 Microchip Technology Inc.
DS22042A-page 1