System monitor meets dual rail needs
A dual rail-to-rail 100V power monitor from Analog Devices, measures current and voltage with ±0.3 per cent accuracy. The LTC2992 is a wide range I2C system monitor that oversees the current, voltage and power of two 0V to 100V rails without additional circuitry, says the company, which recently acquired Linear Technology.
The LTC2992 has flexible power supply options, deriving power from a 3.0 to 100V monitored supply, a 2.7 to 100V secondary supply, or from the on-board shunt regulator. The supply options eliminate the need for a separate buck regulator, shunt regulator or inefficient resistive divider, says ADI, while monitoring any 0 to 100V rail.
The LTC2992 is a single IC that uses three delta-sigma ADCs and a multiplier to provide eight- or 12-bit current and voltage measurements and 24-bit power readings.
The LTC2992’s wide operating range makes it suitable for a variety of applications, especially 48V telecomms equipment, advanced mezzanine cards (AMC) and blade servers. The on-board shunt regulator supports supplies greater than 100V and alo provides support for negative supply monitoring. The LTC2992 measures current and voltage either continuously or on-demand, calculates power and stores all of this information along with minimum and maximum values in I2C accessible registers. Four general purpose I/Os can also be configured as ADC inputs to measure neighbouring auxiliary voltages.
Measurements are made with only ±0.3 per cent of total unadjusted error (TUE) over the entire temperature range, assures ADI. If any parameter trips the user-programmable thresholds, the LTC2992 flags an alert register and pin per the SMBus alert response protocol. The 400kHz 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.
Both the LTC2992 and LTC2992-1 are offered in commercial, industrial and automotive versions, supporting operating temperature ranges from 0 to +70 degree C, –40 to +85 degree C and –40 to +125 degree C, respectively. Both versions are available today in RoHS-compliant, 16-lead 4.0 x 3.0mm DFN and 16-lead MSOP packages.