Features and Benefits

Rail-to-Rail Input Range: 0V to 80V
Wide Input Supply Range: 2.7V to 80V
Shunt Regulator for Supplies >80V
ΔΣ ADC with less than ±0.75% Total Unadjusted Error
12-Bit Resolution for Current and Voltages
Internal Multiplier Calculates 24-Bit Power Value
Stores Minimum and Maximum Values
Alerts When Limits Exceeded
Additional ADC Input Monitors an External Voltage
Continuous Scan and Snapshot Modes
Shutdown Mode with IQ < 80μA
Split SDA for Opto-Isolation
Available in 12-Lead 3mm × 3mm QFN and MSOP Packages

Product details

The LTC2945 is a rail-to-rail system monitor that measures current, voltage, and power. It features an operating range of 2.7V to 80V and includes a shunt regulator for supplies above 80V to allow flexibility in the selection of input supply. The current measurement range of 0V to 80V is independent of the input supply. An onboard 0.75% accurate 12-bit ADC measures load current, input voltage and an auxiliary external voltage. A 24-bit power value is generated by digitally multiplying the measured 12-bit load current and input voltage data. Minimum and maximum values are stored and an overrange alert with programmable thresholds minimizes the need for software polling. Data is reported via a standard I2C interface. Shutdown mode reduces power consumption to 20μA.

The LTC2945 I2C interface includes separate data input and output pins for use with standard or opto-isolated I2C connections. The LTC2945-1 has an inverted data output for use with inverting opto-isolator configurations.