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 Data3/23/2018
DC2156A - Demo Manual9/3/2014
Power System Manager and Super Sequencer Selection Guide2/23/2018
Power and Thermal Monitoring1/9/2017
Very Wide Range I2C Energy Monitor9/3/2014
1% Accurate Energy Monitor6/27/2014
High Accuracy Energy Monitoring Solutions from Analog Devices9/6/2016
I2C Primer: What is I2C? (Part 1)9/2/2016
A Sensible 30A Energy Meter8/26/2016
Understanding Power Monitor Accuracy2/20/2015
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits. Each Linduino-supported product includes an example main program, defined in the LTSketchbook/Part Number folder and driver code, defined in the LTSketchbook/libraries folder.
LTC2946 Companion Parts
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
Sample & Buy
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Please see the latest communication from our CCO regarding lead times.
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.