The MCP9700/9700A and MCP9701/9701A family of
Linear Active Thermistor? Intergrated Circuit (IC) is an
analog temperature sensor that converts temperature
to analog voltage. It’s a low-cost, low-power sensor
with an accuracy of ±2°C from 0°C to +70°C
(MCP9700A/9701A) ±4°C from 0°C to +70°C
(MCP9700/9701) while consuming 6 μA (typical) of
operating current.
Unlike resistive sensors (such as thermistors), the
Linear Active Thermistor IC does not require an
additional signal-conditioning circuit. Therefore, the
biasing circuit development overhead for thermistor
solutions can be avoided by implementing this low-cost
device. The voltage output pin (VOUT) can be directly
connected to the ADC input of a microcontroller. The
MCP9700/9700A and MCP9701/9701A temperature
coefficients are scaled to provide a 1°C/bit resolution
for an 8-bit ADC with a reference voltage of 2.5V and
5V, respectively.
The MCP9700/9700A and MCP9701/9701A provide a
low-cost solution for applications that require measurement
of a relative change of temperature. When measuring
relative change in temperature from +25°C, an
accuracy of ±1°C (typical) can be realized from 0°C to
+70°C. This accuracy can also be achieved by applying
system calibration at +25°C.
In addition, this family is immune to the effects of
parasitic capacitance and can drive large capacitive
loads. This provides Printed Circuit Board (PCB) layout
design flexibility by enabling the device to be remotely
located from the microcontroller. Adding some
capacitance at the output also helps the output
transient response by reducing overshoots or
undershoots. However, capacitive load is not required
for sensor output stability.