General Description
Microchip Technology Inc.’s MCP9804 digital
temperature sensor converts temperatures between
-40°C and +125°C to a digital word with ±0.25°C/±1°C
(typical/maximum) accuracy.
The MCP9804 comes with user-programmable registers
that provide flexibility to temperature sensing
applications. The registers allow user-selectable
settings such as Shutdown or Low-Power modes and
the specification of temperature Alert window limits and
critical output limits. When the temperature changes
beyond the specified boundary limits, the MCP9804
outputs an Alert signal. The user has the option of setting
the Alert output signal polarity as an active-low or activehigh
comparator output for thermostat operation, or as a
temperature Alert interrupt output for microprocessorbased
systems. The Alert output can also be configured
as a critical temperature output only.
This sensor has an industry standard 100 kHz, 2-wire,
SMBus/I2C compatible serial interface, allowing up to
eight or sixteen sensors to be controlled with a single
serial bus (see Table 3-2 for available Address codes).
These features make the MCP9804 ideal for
sophisticated, multi-zone, temperature-monitoring applications.

Features
• Accuracy:
- ±0.25°C (typical) from -40°C to +125°C
- ±1°C (maximum) from -40°C to +125°C
- +0.05°C (typical) lifetime drift
- ±0.0625°C or ±1 LSb (typical) repeatability
• User-Selectable Measurement Resolution:
- +0.5°C, +0.25°C, +0.125°C, +0.0625°C
• User-Programmable Temperature Limits:
- Temperature Window Limit
- Critical Temperature Limit
• User-Programmable Temperature Alert Output
• Operating Voltage Range: 2.7V to 5.5V
• Operating Current: 200 μA (typical)
• Shutdown Current: 0.1 μA (typical)
• 2-wire Interface: I2C™/SMBus Compatible
• Available Packages: 2x3 DFN-8, MSOP-8

Typical Applications
• General Purpose
• Industrial Applications
• Industrial Freezers and Refrigerators
• Food Processing
• Personal Computers and Servers
• PC Peripherals
• Consumer Electronics
• Handheld/Portable Devices