MCP1623/24 Low-Voltage Input Boost Regulator for PIC Microcontrollers Features: General Description: Up to 96% Typical Efficiency The MCP1623/24 is a compact, high-efficiency, fixed frequency, synchronous step-up DC-DC converter. It 425 mA Typical Peak Input Current Limit: provides an easy-to-use power supply solution for PIC -I > 50 mA 1.2V V , 3.3V V OUT IN OUT microcontroller applications powered by either one-cell, -I > 175 mA 2.4V V , 3.3V V OUT IN OUT two-cell, or three-cell alkaline, NiCd, NiMH, one-cell -I > 175 mA 3.3V V 5.0V V OUT IN, OUT Li-Ion or Li-Polymer batteries. Low Start-up Voltage: 0.65V, typical 3.3V V OUT Low-voltage technology allows the regulator to start-up 1 mA without high inrush current or output voltage overshoot Low Operating Input Voltage: 0.35V, typical from a low 0.65V input. High efficiency is accomplished by 3.3V 1 mA OUT integrating the low resistance N-Channel Boost switch Adjustable Output Voltage Range: 2.0V to 5.5V and synchronous P-Channel switch. All compensation and protection circuitry are integrated to minimize external Maximum Input Voltage V < 5.5V OUT components. For standby applications, the MCP1624 Automatic PFM/PWM Operation (MCP1624) operates and consumes only 19 A while operating at no PWM-only Operation (MCP1623) load. The MCP1623 device option is available that 500 kHz PWM Frequency operates in PWM-only mode. Low Device Quiescent Current: 19 A, typical A true Load Disconnect mode provides input to output PFM mode isolation while disabled (EN = GND) by removing the Internal Synchronous Rectifier normal boost regulator diode path from input to output. Internal Compensation This mode consumes less than 1 A of input current. Inrush Current Limiting and Internal Soft-Start Output voltage is set by a small external resistor True Load Disconnect divider. Shutdown Current (All States): < 1 A Low Noise, Anti-Ringing Control Packaging Overtemperature Protection SOT-23-6 Package MCP1623/24 6-Lead SOT-23 Applications: V SW 1 6 IN One, Two and Three Cell Alkaline and NiMH/NiCd Low-Power PIC Microcontroller Applications GND V 2 5 OUT 3 EN 4 V FB 2010 Microchip Technology Inc. DS41420B-page 1MCP1623/24 L 1 4.7 H V OUT V 3.3V IN SW V 0.9V To 1.7V OUT V IN VDD 976 K C C OUT IN + V 10 F 4.7 F FB EN PIC MCU 562 K VSS GND - MCP1623/24 Typical Application Circuit 100 V = 2.5V IN 90 80 V = 1.2V IN 70 V = 0.8V IN 60 50 40 30 20 0.01 0.1 1 10 100 1000 I (mA) OUT MCP1624 Efficiency vs. I , V = 3.3V OUT OUT FIGURE 1: Typical Application. DS41420B-page 2 2010 Microchip Technology Inc. ALKALINE Efficiency (%)