LTC2946CMS#PBF

Overview

The LTC2946CMS#PBF is a single-channel rail-to-rail system monitor manufactured by Analog Devices Inc. It measures current, voltage, power, charge, and energy via an I2C interface. The device operates within a common-mode voltage range of 2.7 V to 100 V and includes an internal shunt regulator for supplies exceeding 100 V. Key electrical parameters include a maximum supply voltage of 100 V, a typical operating supply current of 700 µA, and a gain error of 0.4%. It features a common-mode input voltage range up to 100 V and an input offset voltage of 77 µV. The component is housed in a 16-pin MSOP package and supports operation from -40°C to +125°C.

Feature Summary

• Rail-to-rail system monitoring capability for comprehensive measurement of current, voltage, power, charge, and energy.
• Integrated I2C interface for digital communication and data retrieval.
• Internal shunt regulator designed to tolerate supply voltages above the standard 100 V operating limit.

Applications

• Monitoring wide-range negative power supplies, such as -48V telecom systems.
• Bidirectional power monitoring with energy and charge tracking in forward paths.
• Harsh environment applications requiring tolerance for high-voltage transients using the INTVCC shunt regulator.

Procurement Notes

Verify the specific suffix CMS against the manufacturer's datasheet to confirm package type and temperature grade. Ensure the I2C address configuration matches the system design requirements. Confirm availability status with authorized distributors, as supply levels may vary. Check for RoHS compliance documentation if required by project specifications. Validate that the 16-MSOP footprint aligns with the PCB layout constraints.

Selection Notes

Select this part when a single-channel monitor with integrated energy accumulation is required. The 100 V common-mode range suits high-side sensing in industrial or automotive contexts. Consider the 700 µA supply current for low-power efficiency needs. The internal shunt regulator simplifies designs involving transient voltages above 100 V. Compare against other LTC2946 variants if different packaging or accuracy grades are needed.

Part Context

The LTC2946 series comprises rail-to-rail system monitors capable of measuring multiple electrical parameters. The CMS variant specifically denotes the commercial temperature grade and MSOP packaging. This family integrates analog front-end circuitry with digital processing for direct I2C output. It eliminates the need for external microcontrollers to perform complex calculations related to power and energy.

Replacement Considerations

Direct substitutes within the same series include LTC2946CMS-1#PBF and LTC2946HMS#PBF. Verify if the '-1' suffix indicates necessary functional differences regarding accuracy or speed. Cross-reference pinouts and register maps to ensure compatibility during replacement.