The LTC2945 is a rail-to-rail system monitor that measures current, voltage, and power. It features an operating range of 2.7 to 80 V and includes a shunt regulator for supplies above 80 V to allow use with various input supply voltages. The current measurement range of 0 to 80 V 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 over-range alert with programmable thresholds minimizes the need for software polling. Data is reported via a standard I2C interface, and a shutdown mode reduces power consumption to 20 μA.
The LTC2945 I2C interface includes separate data input and output pins for use with standard or optoisolated I2C connections. The LTC2945-1 has an inverted data output for use with inverting opto-isolator configurations. Applications include telecom infrastructure, industrial, automotive, and consumer products.
- Rail-to-Rail Input Range: 0 to 80 V
- Wide Input Supply Range: 2.7 to 80 V
- Shunt Regulator for Supplies >80 V
- 12-Bit Resolution for Current and Voltages
- Internal Multiplier Calculates 24-Bit Power Value
- Stores Minimum and Maximum Values
- Additional ADC Input Monitors an External Voltage
- Internal Digital Multiplier Calculates Power
- Continuous Scan and Snapshot Modes
- Shutdown Mode with IQ <80 μA
- Split SDA for Opto-Isolation
- Available in 12-Lead 3 × 3 mm QFN and MSOP Packages
Linear Technology Corp., 1630 McCarthy Blvd., Milpitas, CA 95035. Phone: (408) 432-1900.