MCP1601T-I/MS Microchip

MCP1601 500 mA Synchronous BUCK Regulator Features Description Input Range of 2.7V to 5.5V The MCP1601 is a fully integrated synchronous BUCK (step down) DC/DC converter for battery powered sys- 3 Operating Modes: PWM, PFM and LDO tems. With an input operating range of 2.7V to 5.5V, the Integrated BUCK and Synchronous Switches MCP1601 is ideal for applications being powered by Ceramic or Electrolytic Input/Output Filtering one single cell Li-Ion, 2 to 3 cell NiMH, NiCd or alkaline Capacitors sources. Output voltages can range from 0.9V to V to IN 750 kHz Fixed Switching Frequency accommodate a wide range of applications. Efficiency Oscillator Synchronization to 1 MHz PWM Mode can exceed 92% while operating at 750 kHz with load current capability up to 500 mA. The MCP1601 is used Auto-Switching from PWM/PFM Operation to minimize space, cost and wasted energy. 100% Duty Cycle Capable for Low Input Voltage The PWM mode switching frequency is internally set to 500 mA Continuous Output Current Capability a fixed 750 kHz allowing the use of low profile, surface Integrated Under-Voltage Lock-Out Protection mount inductors and ceramic capacitors while Integrated Over-Temperature Protection maintaining a typical efficiency of 92%. Integrated Soft Start Circuitry The MCP1601 is capable of three distinct operating Low Output Voltage Capability to 0.9V modes: PWM, PFM and Low Drop Out. Temperature Range: -40C to +85C When operating in PWM (pulse width modulation) Small 8-Pin MSOP Package mode, the DC/DC converter switches at a single high frequency determined by either the internal 750 kHz Applications oscillator or external synchronization frequency. Low Power Handheld CPUs and DSPs For applications that operate at very light to no load for Cellular Phones extended periods of time, the MCP1601 is capable of Organizers and PDAs operating in PFM (pulse frequency modulation mode) to reduce the number of switching cycles/sec and Digital Cameras consume less energy. +5V or +3.3V Distributed Voltages The third mode of operation (LDO mode) occurs when USB Powered Devices the input voltage approaches the output voltage and the BUCK duty cycle approaches 100%. The MCP1601 will Package Type enter a low drop out mode and the high-side P-Channel BUCK switch will saturate, providing the output with the 8-Pin MSOP maximum voltage possible. V 1 8 L IN X The MCP1601 has integrated over-current protection, over-temperature protection and UVLO (Under Voltage SHDN 2 7 P GND MCP1601 Lockout) to provide for a fail safe solution with no FB 3 6 V OUT external components. A 4 5 SYNC/PWM The MCP1601 is available in the 8-pin MSOP package, GND with an operating temperature range of -40C to +85C. 2003-2013 Microchip Technology Inc. DS21762B-page 1MCP1601 Typical Application Typical Application (2.7V to 4.2V) V Range L Range OUT 10 H to 22 H 1.2V to 3.3V MCP1601 I = 0 mA to 400 mA 10 H OUT V 1 L 8 IN X C OUT 7 2 SHDN P GND 10 F Input C IN FB V 6 3 OUT Voltage C Range OUT 10 F SYNC/ 2.7V-4.2V 5 4 A 10 F to 47 F GND PWM R 1 C 1 250 k 47 pF (for 1.8V) R 2 200 k Functional Block Diagram V IN UVLO V OUT Internal Internal Band Gap Buffered 0.8V Output SHDN Circuit Enable Out Reference Enable Duty + V 12 pF REF Clamp 800 k 10 pF - Cycle Soft Start R COMP C COMP FB I P SENSE - Duty 3M EA PWM Latch + + Cycle 0.8V R - Clamp A GND 10% - 90% L X Feedforward Oscillator Inset OUT Timing K*V IN S SQW I N SENSE I P SENSE V - REF PFM Mode Timing PFM Comparator P + GND - V REF P GND I N SENSE A GND - V SYNC/PWM REF A GND DS21762B-page 2 2003-2013 Microchip Technology Inc.