Microchip MCP1631 PWM Modulators 17.11.2021

Microchip has developed high-speed PWM modulators that can turn most general-purpose microcontrollers into full-fledged switching power converter controllers with flexible functionality. Each of the microcircuits of the MCP1631 line contains a basic set of nodes used in modern PWM controllers, including a high-speed PWM modulator, MOSFET driver, amplifiers, comparators, as well as additional analog and digital elements that connect all components of the microcircuit into a single system. At the same time, high-level control of the converter, including the formation of the conversion frequency, setting the output voltage and output current, is carried out programmatically using a general-purpose microcontroller by generating and processing just a few signals.

Chips MCP1631 and MCP1631HV are designed to create current regulators, while MCP1631V and MCP1631VHV are the basis for creating voltage regulators. The power section of the MCP1631 and MCP1631HV microcircuits can operate from primary power supplies with a voltage of 3,0 ... 5,5 V. For higher voltage applications, you should use the MCP1631HV or MCP1631VHV microcircuits, the input voltage operating range of which is extended to 16 V. At the same time, on-chip High-voltage versions of the MCP1631 chips (MCP1631HV and MCP1631VHV) have an additional LDO regulator with an output voltage of 3,3 or 5 V and a maximum output current of up to 250 mA, which can be used to power the microcontroller and other auxiliary nodes.

Since all high-level functions are implemented in software, the application assignment of the same circuit can be easily changed by modifying the source code or by changing settings in non-volatile memory (if the software supports such a function). For example, the same charger can be easily reconfigured to work with lithium-ion, nickel-cadmium, nickel-metal hydride or lead-acid batteries, and the maximum number and capacity of cells is determined only by the capabilities of the power unit, and the voltage limit thresholds, values charging currents, as well as charge macroalgorithms are generated by software. In addition, the replacement of high-level software will allow, without any modification of the power part, to turn the charger into, for example, an LED driver with a customizable type and number of lamps.

For the MCP1631 chips to work properly, external software must generate signals to set the output voltage, output current, and the frequency and duty cycle of the PWM signal to control the power transistor. If necessary, the microcontroller can also provide temperature control of power transistors or battery cells. The rest of the low-level functions, including surge protection, are handled by the nodes of the MCP1631 chips.

Features of MCP1631 chips:

the ability to create universal chargers with programmable settings for working with different types and numbers of battery cells;
the possibility of creating converters with a switching frequency of up to 2 MHz;
the ability to create power systems with intelligent functions (Intelligent Power Systems);
the ability to create both current stabilizers (MCP1631, MCP1631HV) and voltage stabilizers (MCP1631V, MCP1631VHV)
the ability to work with primary power supplies with voltage up to 16 V (MCP1631HV, MCP1631VHV);
the presence of an additional LDO stabilizer with an output voltage of +3,3 or +5,0 V and an output current of up to 250 mA (MCP1631HV, MCP1631VHV);
setting the switching frequency, maximum duty cycle, output voltage and output current using an external microcontroller;
the presence of an error amplifier, as well as signal amplifiers generated by voltage and current sensors;
presence of an overvoltage protection comparator;
the presence of a protection unit against lowering the input voltage;
the presence of an external MOSFET driver with an output current of up to 1 A;
low current consumption in off mode (approximately 2,4 μA);
the possibility of implementing temperature control (using a microcontroller);
support for multiple package types: 20-pin TSSOP, SSOP (all versions), and 20-pin 4 x 4 mm QFN (MCP1631 and MCP1631V only).
The main applications in which the MCP1631 family of chips can be used are:
universal chargers that support different types of batteries;
LED lighting and illumination systems;
general-purpose pulse converters based on SEPIC topology;
USB charging.