Multi-channel temperature sensor IC supports remote diode-based readings

March 29, 2016 // By Graham Prophet
Measurements of lower-temperature, outdoor and industrial applications achieve greater accuracy with Microchip’s MCP990X multi-channel temp sensor family; remote diode measurement with resistance error correction enables accurate readings of up to 0.5m away from the IC

Microchip Technology’s MCP990X family of System Management Bus (SMBus) temp sensor ICs has been designed for monitoring of up to four channels in cold, outdoor and industrial low-temperature applications ranging from freezers and refrigerators to base stations and remote radio units. With ±1°C maximum accuracy for both external and internal diode temperatures from -40°C to +65°C, these ICs provide a low-cost, highly flexible solution where precision is needed at lower temperatures.


Features of the MCP990X family include remote diode temperature measurement with resistance error correction that compensates for voltage drops from connectors and long board traces, enabling accurate readings of up to 50 cm away from the IC. Injected system noise from components such as DC/DC converters and backlight inverters is also minimised with a sample-frequency hopping filter, allowing for easier placement and routing. The combination of these features with options for dual, triple and quad temperature monitoring provides for a wider range of measurement opportunities for an entire system with a single IC.

“Extending our thermal-management portfolio to include a focus on colder remote and industrial applications gives us a unique offering in the industry,” the company comments.


Compact package options that take up less silicon space on the PCB and allow for smaller system solutions and better product design for temperature-critical applications include a 2 x 2 mm footprint for the MCP9902 dual-channel temperature sensor. The IC is the smallest temperature sensor in Microchip’s portfolio and one-third smaller than the company’s previous generation dual temperature sensor. A 3 x 3 footprint package is available for the MCP9903 triple and MCP9904 quad temp sensors.


The MCP9902 Evaluation Board (part # ADM00615) costs $35.00; all three members of the MCP990X are available starting at $0.46 (5,000). The MCP9902 is offered in an 8-pin, 2 x 2 WDFN package. The MCP9903 and MCP9904 are available in a 10-pin, 3 x 3 DFN package.