Digital control of dual 13A µModule regulator provides remote monitoring & control

September 24, 2013 // By Graham Prophet
Linear Technology's LTM4676 is a dual 13A or single 26A μModule (micromodule) step-down DC/DC regulator with a serial digital interface. The interface enables system designers and remote operators to command and supervise a system’s power condition and consumption.

The ability to digitally change power supply parameters reduces time-to-market and down time by eliminating what would have previously required physical hardware, circuit, and/or system bill-of-material modifications. The LTM4676 simplifies system characterisation, optimisation and data mining during prototyping, deployment and field operation.

In addition to delivering power to a point-of-load, the LTM4676 features configurability and telemetry-monitoring of power and power management parameters over PMBus. Its 2-wire serial interface allows outputs to be margined, tuned and ramped up and down at programmable slew rates with sequencing delay times. Input and output currents and voltages, output power, temperature, uptime and peak values are readable. The device comprises of fast, dual analogue control loops, precision mixed-signal circuitry, EEPROM, power MOSFETs, inductors and supporting components housed in a 16 x 16 x 5.01mm BGA (ball grid array) package.

To evaluate the performance of the LTM4676, the LTpowerPlay GUI (graphic user interface, free to download), USB-to-PMBus converter and demo kits are available.

With ±1% maximum DC output error over temperature, ±2.5% current read back accuracy, integrated 16-bit delta-sigma ADC and EEPROM, the LTM4676 combines analogue switching regulator performance with precision mixed signal data acquisition. The LTM4676 operates from a 4.5V to 26.5V input supply and steps down V IN to two outputs ranging from 0.5V up to 5.4V. Two channels can current-share to provide up to 26A. Up to four LTM4676 devices can be multiphased to share current up to 100A output. At start-up, output voltages, switching frequency and channel phase angle assignments can be set by pin-strapping resistors. The LTM4676 internal operating temperature range is from -40ºC to 125ºC; it costs $33.55 (1000).

Linear Technology;