MCP990x Series Temperature Sensors

The MCP9902 / 3 / 4 are high-accuracy, low-cost, system management bus (SMBus) temperature sensors from Microchip Technology. Advanced features, such as resistance error correction (REC), beta compensation (to support CPU diodes requiring the BJT / transistor model including 45 nm, 65 nm, and 90 nm processors), and automatic diode type detection, combine to provide a robust solution for complex environmental monitoring applications.

The MCP9902 monitors two temperature channels (one external and one internal). The MCP9903 monitors three temperature channels and the MCP9904 monitors four temperature channels. It provides ±1ºC accuracy for both external and internal diode temperatures.

Resistance error correction automatically eliminates the temperature error caused by series resistance, allowing greater flexibility in routing thermal diodes. Beta compensation eliminates temperature errors caused by low, variable beta transistors, common in today's fine geometry processors. The automatic beta detection feature monitors each external diode/transistor and determines the optimum sensor settings for accurate temperature measurements regardless of processor technology. This frees the user from providing unique sensor configurations for each temperature monitoring application. These advanced features, plus ±1°C measurement accuracy, provide a low-cost, highly flexible and accurate solution for critical temperature monitoring applications.