Digital power system manager can lower data centre cooling costs

Monitoring circuit board power and energy use is a prerequisite for managing, optimising and reducing their consumption in order to lower server rack and data center cooling and utility costs. To meet these conditions, Analog Devices has developed the Power by Linear LTC2972, a two-channel power system manager.

The LTC2972 features current, power and energy monitoring of the intermediate bus input to point-of-load (PoL) converters. According to Analog Devices, the LTC2972 relieves polling and computation duties for the host, 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.

The manager also adds 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 16-bit analogue to digital converter (ADC) with 0.25 per cent total unadjusted error (TUE), improving board yields and long-term performance, adds Analog Devices. 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; this can simplify failure analysis and provides 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 co-ordinate sequencing and fault management of more than two rails. PMBus-compatible commands are used for flexible programming and data read-back 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 0 to 70 degree C commercial and −40 to +105 degree C industrial temperature ranges, the LTC2972 is offered in a 44-pin 6.0 x 7.0mm QFN package. Device samples and evaluation circuit boards are available online or from Analog Devices sales offices.