Features

• Rail-to-Rail Input Range: 0V to 100V
• Wide Input Supply Range: 2.7V to 100V
• Shunt Regulator for Supplies >100V
• ΔΣ ADC with Less Than ±0.4% Total Unadjusted Error
• 12-Bit Resolution for Current and Voltages
• ±1% Accurate Power and Energy Measurements
• ±0.6% Accurate Current and Charge Measurements
• Additional ADC Input Monitors an External Voltage
• Internal ±5% or External Time Bases
• Continuous Scan and Snapshot Modes
• Stores Minimum and Maximum Values
• Alerts When Limits Exceeded
• Split SDA Pin Eases Opto-Isolation
• Shutdown Mode with I_Q < 40μA
• Available in 4mm × 3mm DFN and 16-Lead MSOP Packages

Typical Application

Description

The LTC®2946 is a rail-to-rail system monitor that measures current, voltage, power, charge and energy. It features an operating range of 2.7V to 100V and includes a shunt regulator for supplies above 100V. The current measurement common mode range of 0V to 100V is independent of the input supply. A 12-bit ADC measures load current, input voltage and an auxiliary external voltage. Load current and internally calculated power are integrated over an external clock or crystal or internal oscillator time base for charge and energy. An accurate time base allows the LTC2946 to provide measurement accuracy of better than ±0.6% for charge and ±1% for power and energy. 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.

The LTC2946 I²C interface includes separate data input and output pins for use with standard or opto-isolated I²C connections. The LTC2946-1 has an inverted data output for use with inverting opto-isolator configurations.