Microchip MCP1632 | Demoboard MCP1632-BAE/MS

Description

switch-mode power converter. When combined with an external microcontroller, theMCP1632 can be used to implement different intelligent converters like thosenecessary for battery chargers.The power train of this application uses the Single-Ended Primary Inductor Converter(SEPIC) topology. This topology offers buck-boost functionality and also hasnon-pulsating input current.The converter provides constant voltage with limited current at the output, necessaryfor certain battery charging applications (ex. Li-Ion-based batteries).The output voltage is measured with a voltage divider resistor pair (R1, R5). Thisvoltage must be precisely 4.2V, required by the battery chemistry.The average current in the L1B inductor, which is also the output current of theconverter, is sensed using a 0.1Ω shunt resistor (RS). As the voltage across the shuntresistor is negative, a -10x amplifier (U3) is used for battery charging current sensing.The conversion gain of this circuit is 1V/A.The PWM output available from the PIC12F1822 microcontroller is used to control thereference voltage of the MCP1632 using the circuit created with D2 and R3 components.Maximum output current is set by the PIC12F1822 microcontroller.

Features

Input voltage: +4.5V to +12V

• Load disconnect protection software configurable
• Typical output current: 1000 mA
• Maximum output current: 1500 mA (with firmware adjustments)
• Typical output power: 4.2W (maximum 7W at +25°C degree ambient temperature)
• Fully protected against Short-Circuit and No Load condition
• Figure 1-1 shows a simplified block diagram of the application

More information

• Datasheet
• IC product information