Analog Temperature Sensor
Contents
What is an Analog Temperature Sensor?
An analog (or voltage output) temperature sensor provides a voltage level that is directly proportional to the measured temperature. In simple words, these devices convert temperature to voltage.
Why Should I Use an Analog Temperature Sensor?
In many applications, monitoring temperature can improve system performance, reliability, and product quality. It can be used to replace thermistor solutions with the following benefits:
- Silicon temperature sensors are linear over a wider temperature range, while the temperature coefficient of a thermistor is non-linear.
- Silicon temperature sensors do not require an excitation current, which lowers power consumption.
- Silicon temperature sensors do not require external circuitry, hence minimizing cost and board area.
The figure below shows an application example using a thermistor:
- RNTC is the thermistor device.
- MCP6XX represents Microchip Technology's op amp products
- MCP32XX represents Microchip's Successive Approximation Register (SAR) Analog-to-Digital Converters
- Microchip's Introduction to Operational Amplifiers page
The figure below shows a temperature sensing application using an MCP9700/1, one of Microchip's analog temperature (thermal) sensors. Notice that the number of devices required for the application compared to the thermistor application is significantly reduced.
Temperature Sensor Application Examples
Application examples that deal with temperature include:
- Power supply thermal shutdown
- Thermostat control
- Fan control
- Automotive battery conditioner
- HVAC
- Refrigerator
- Freezer
- Rice cookers
- Power amplifier
- Food warmers
- Base stations
- STE top boxes
- PC/Server and more
Microchip's temperature (thermal) sensing products:
MCP9700/01
Specification highlights:
- ±2 °C from -10 °C to +70 °C
- Offered in SC70 and TO92 packaging
MCP9700A/1A
Specification highlights:
- ±2 °C from -40 °C to +125 °C
- Offered in pin compatible replacement to TC1046/7/7A