MCP1642B/D 1.8A Input Current Switch, 1 MHz Low-Voltage Start-Up Synchronous Boost Regulator Features General Description Up to 96% Typical Efficiency The MCP1642B/D devices are compact, high-efficiency, fixed-frequency, synchronous step-up 1.8A Typical Peak Input Current Limit: DC-DC converters. This family of devices provides an -I > 175 mA 1.2V V , 3.3V V OUT IN OUT easy-to-use power supply solution for applications -I > 600 mA 2.4V V , 3.3V V OUT IN OUT powered by either one-cell, two-cell, or three-cell -I > 800 mA 3.3V V , 5.0V V OUT IN OUT alkaline, Ultimate Lithium, NiCd, NiMH, one-cell Li-Ion -I > 1A V > 3.6V, 5.0V V or Li-Polymer batteries. OUT IN OUT Low Start-Up Voltage: 0.65V, typical 3.3V V Low-voltage technology allows the regulator to start-up OUT 1 mA without high inrush current or output voltage overshoot Low Operating Input Voltage: 0.35V, typical 3.3V from a low voltage input. High efficiency is accomplished by integrating the low-resistance V 1 mA OUT N-Channel Boost switch and synchronous P-Channel Output Voltage Range: switch. All compensation and protection circuitry are - Reference Voltage, V =1.21V FB integrated to minimize the number of external - 1.8V to 5.5V for the adjustable device option components. An open-drain Power Good output is - 1.8V, 3.0V, 3.3V and 5.0V for fixed V OUT provided to indicate when the output voltage is within options 10% of regulation and facilitates the interface with an Maximum Input Voltage V <5.5V MCU. For standby applications, MCP1642B provides a OUT true output disconnect from input to output while in PWM Operation: 1 MHz shutdown (EN=GND). An additional device option - Low Noise, Anti-Ringing Control (MCP1642D) is available and connects input to output Power Good Open-Drain Output bypass while in shutdown. Both options consume less Internal Synchronous Rectifier than 1 A of input current. Internal Compensation For the adjustable (ADJ) device options, the output Inrush Current Limiting and Internal Soft-Start voltage is set by a small external resistor divider. Fixed device options do not require external divider V Selectable, Logic-Controlled Shutdown States: OUT resistors. Two package options, 8-lead MSOP and 8- - True Load Disconnect Option (MCP1642B) lead 2x3 DFN, are available. - Input-to-Output Bypass Option (MCP1642D) Shutdown Current (All States): 1 A Package Types Overtemperature Protection MCP1642B/D-xx MCP1642B/D-xx Available Packages: MSOP 2x3 DFN* - 8-Lead MSOP V EN 8 1 IN EN 1 8 V IN - 8-Lead 2x3 DFN S NC 2 7 GND NC 2 7 S EP GND Applications 9 PG 3 P PG 3 6 P 6 GND GND One, Two and Three-Cell Alkaline, Lithium V 4 5 SW OUT 4 V 5 SW Ultimate and NiMH/NiCd Portable Products OUT Single-Cell Li-Ion to 5V Converters MCP1642B/D-ADJ MCP1642B/D-ADJ MSOP 2x3 DFN* PIC MCU Power USB Emergency Backup Charger from Batteries V EN 1 8 IN EN 1 8 V IN Personal Medical Products S V 2 7 GND FB V 2 7 S EP FB GND Wireless Sensors 9 PG 3 P PG 3 6 P Hand-Held Instruments 6 GND GND V 4 5 SW GPS Receivers OUT 4 V 5 SW OUT +3.3V to +5.0V Distributed Power Supply * Includes Exposed Thermal Pad (EP) see Table 3-1. 2014 Microchip Technology Inc. DS20005253A-page 1MCP1642B/D Typical Application L 1 4.7 H V OUT C IN 3.3V SW 4.7...10 F V V = 0.9 to 1.6V OUT IN V IN C OUT + MCP1642B-33 4.7...10 F NC PG EN GND - ON OFF L 4.7 H V OUT C IN 5.0V SW 4.7...10 F V OUT R V TOP V = 1.8 to 3.2V IN IN 976 k C OUT MCP1642D-ADJ + 4.7...10 F V FB R R PG BOT 1M 309 k EN - ON + OFF PG GND To PIC MCU I/O From PIC MCU I/O - 100 90 V = 1.2V, V = 3.3V IN OUT 80 70 V = 2.5V, V = 5.0V IN OUT 60 50 40 30 20 10 0 1 10 100 1000 I (mA) OUT DS20005253A-page 2 2014 Microchip Technology Inc. ALKALINE Efficiency (%) ALKALINE ALKALINE