Dual rail-to-rail 100-V power monitor measures current, voltage with ±0.3% accuracy

Nov. 2, 2017

Milpitas, CA, and Norwood, MA. Analog Devices Inc., which recently acquired Linear Technology Corp., has announced the LTC2992, a wide-range I²C system monitor that monitors the current, voltage, and power of two 0-V to 100-V rails without additional circuitry. The LTC2992 has flexible power supply options, deriving power from a 3-V to 100-V monitored supply, a 2.7-V to 100-V secondary supply, or from the onboard shunt regulator. These supply options eliminate the need for a separate buck regulator, shunt regulator, or inefficient resistive divider while monitoring any 0-V to 100-V rail. The LTC2992 is a simple, single-IC solution that uses three delta-sigma ADCs and a multiplier to provide 8- or 12-bit current and voltage measurements and 24-bit power readings.

The LTC2992’s wide operating range is suitable for many applications, especially 48-V telecom equipment, advanced mezzanine cards (AMC), and blade servers. The onboard shunt regulator provides support for supplies greater than 100 V and negative supply monitoring. The LTC2992 measures current and voltage either continuously or on-demand, calculates power, and stores all this information along with minimum and maximum values in I²C-accessible registers. Four GPIOs can also be configured as ADC inputs to measure neighboring auxiliary voltages. Measurements are made with only ±0.3% of total unadjusted error (TUE) over the entire temperature range. If any parameter trips the user-programmable thresholds, the LTC2992 flags an alert register and pin per the SMBus alert response protocol. The 400-kHz I²C interface features nine device addresses, a stuck bus reset timer, and a split SDA pin that simplifies I²C opto-isolation. The LTC2992-1 version offers an inverted data output I²C pin for use with inverting opto-isolator configurations.

The LTC2992 and LTC2992-1 are offered in commercial, industrial, and automotive versions, supporting operating temperature ranges from 0°C to 70°C, -40°C to +85°C and -40°C to +125°C, respectively. Both versions are available today in RoHS-compliant, 16-lead 4-mm x 3-mm DFN and 16-lead MSOP packages. Pricing starts at $3.85 each in 1,000-piece quantities.



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