PIC core gives 42V digitally controlled analogue buck converter more flexibility

May 09, 2017 // By Nick Flaherty
single-chip MCP19122/3 DEPA PIC controller meets the USB-PD requirements
Microchip has launched a Digitally-Enhanced Power Analogue (DEPA) buck controller for DC-DC power conversion which offers more flexibility than other analogue control architectures on the market today.

The single-chip MCP19122/3 controls DC-DC converters and is capable of accepting a high-voltage input up to 42V while simultaneously regulating a wide output voltage range of 0.3V to 16V without any external components or drivers.

The internal PIC microcontroller in the MCP19122/3 can dynamically adjust the operating frequency, over- and under-voltage lockout thresholds, current limits, soft-start, voltage or current output setpoints and maximum duty cycle. This level of configurability offers many application benefits. For example, the MCP19123 can dynamically adjust the voltage output to meet USB Power Delivery requirements, while also adjusting the output over-voltage lockout to maintain tight protection limits corresponding to each output voltage level.

The MCP19123 buck controller offers many unique capabilities, including a programmable differential input amplifier used to optimise performance and minimise system voltage error. This configurability allows for a wide output voltage range commonly seen in USB power and battery-charger applications. Improving integration in larger systems, the device can synchronise to an external clock and voltage reference, or provide the internal system clock and reference to other devices for synchronisation. In server or communications equipment, this allows for seamless power-up and accurate tracking of power consumption throughout the board.

For high-power applications, multiple outputs can operate in parallel providing system redundancy for improved system reliability. Combined with an on-board programmable diagnostic and fault detection capability that is unmatched in the industry, the MCP19122/3 is ideal for high-performance intelligent power applications.

This device also offers higher accuracy for an adjustable output power supply. An MCP19122/3 DC-DC converter implementation can maintain an initial 0.5 percent or better output voltage accuracy. In addition to the tight voltage regulation, the MCP19122/3 is designed to deliver industry-leading current measurement by using a lossless inductor current-sense method with specialised internal measurement calibrations. The device can directly accept a common-mode signal up to 16V and report the load current to within 5 percent accuracy for most applications, with an emulated average current mode control