Power systems monitors current, power and energy

The LTC2972 is a 2-channel power system manager from Analog Devices and provides current, power and energy monitoring of the intermediate bus input to point-of-load (POL) converters.

Monitoring circuit board power and energy use is a prerequisite for efficiently managing and reducing their consumption in order to lower server rack and data centre cooling and utility costs.

The LTC2972 relieves the host of polling and computation by providing the input energy, reported in joules, and the elapsed time through a PMBus interface.

When combined with its digital measurements of POL output voltages, currents, and power, the LTC2972 enables long-term monitoring of a power system’s conversion efficiency.

It also adds comprehensive software-based monitoring and control to the power systems of FPGA, ASIC, and DSP boards, accelerating time to market, enhancing system reliability, and optimising board energy consumption.

Supply output voltages are trimmed, margined, and monitored using a best-in-class 16-bit analogue-to-digital converter (ADC) with 0.25% total unadjusted error (TUE), improving board yields and long-term performance. Supply output currents are measured using a sense resistor, inductor DCR, or the IMON output of a power supply.

Supply sequencing, supervision, and EEPROM fault-logging are built in. Faults trigger EEPROM black box recording, simplifying failure analysis while providing insight into future system improvements.

Programmable power good, or general-purpose input/output (GPIO), pins are available with each channel.The LTC2972 connects with other power system managers to coordinate sequencing and fault management of more than two rails.

PMBus-compatible commands are used for flexible programming and data readback of the power system.

Configuration is accomplished through the LTpowerPlay development environment, which supports all Power by Linear power system management (PSM) devices. Once programmed, no software coding is needed for autonomous operation.

Specified over the 0oC to 70oC commercial and −40oC to 105oC industrial temperature ranges, the LTC2972 is offered in a 44-pin 6mm x 7mm QFN package.

Neil Tyler