Overview
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
Product Details
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.
Applications
- 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)
Documentation
Reliability Data (1)
Evaluation Kit Manuals (1)
Tools & Simulations
LTspice
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
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.
Linduino code repository on GitHub and instructions on how to use the code.

Reference Materials
Solutions Bulletins & Brochures (1)
Press Releases (1)
Design Resources
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.
PCN-PDN Information
Sample & Buy
The USA 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. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.