MCP9700AT-ELT

MCP9700/9700A/9700B and MCP9701/9701A
sensors with Linear Active Thermistor Integrated
Circuit (IC) comprise a family of analog temperature
sensors that convert temperature to analog voltage.
The low-cost, low-power sensors feature an accuracy
of ±1°C from +20°C to +70°C (MCP9700B), ±2°C from
0°C to +70°C (MCP9700A/9701A) and ±4°C from 0°C
to +70°C (MCP9700/9701) while consuming 6 µA
(typical) of operating current.
Unlike resistive sensors, e.g., 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 a sensor from these low-cost
devices. The Voltage Output pin (VOUT) can be directly
connected to the ADC input of a microcontroller. The
MCP9700/9700A/9700B 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/
9700B output 0.1°C/bit for a 12-bit ADC with 4.096V
reference.
The MCP9700/9700A/9700B 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. The
MCP9700B can measure temperature with ±1°C from
+20°C to +70°C without any system calibration.
In addition, this family of devices 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 the stability of sensor output.