LTC2946: Wide Range I2C Power, Charge and Energy Monitor Data Sheet3/25/2015462K
Features and Benefits
- 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 IQ < 40μA
- Available in 4mm × 3mm DFN and 16-Lead MSOP Packages
The LTC2946 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.
- Telecom Infrastructure
- Industrial Equipment
- General Purpose Energy Measurement
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2156A features the LTC2946 rail-to-rail system monitor that measures current, voltage, power, energy and charge. It features an operating range of 2.7V to 100V and includes a shunt regulator for operation from supplies above 100V to allow flexibility in the selection of input supply. The current measurement range of 0V to 100V is independent of the input supply. An onboard, 0.4% 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. Energy and charge data are generated by integrating power and current. 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.
Documentation & Resources
R554 Reliability Data3/23/201815 K
DC2156A - Demo Manual9/3/20142M
Power System Manager and Super Sequencer Selection Guide2/23/20184M
Power and Thermal Monitoring1/9/20171M
Very Wide Range I2C Energy Monitor9/3/2014608K
1% Accurate Energy Monitor6/27/20141M
High Accuracy Energy Monitoring Solutions from Linear Technology9/6/2016
I2C Primer: What is I2C? (Part 1)9/2/2016
A Sensible 30A Energy Meter8/26/20161M
Understanding Power Monitor Accuracy2/20/2015
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