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General Description

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 ¡À1¡ãC from +20¡ãC to +70¡ãC (MCP9700B), ¡À2¡ãC from

0¡ãC to +70¡ãC (MCP9700A/9701A) and ¡À4¡ãC from 0¡ãC

to +70¡ãC (MCP9700/9701) while consuming 6 ¦ÌA (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¡ãC/bit

resolution for an 8-bit ADC with a reference voltage of

2.5V and 5V, respectively. The MCP9700/9700A/

9700B output 0.1¡ãC/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¡ãC, an accuracy of ¡À1¡ãC (typical) can be realized

from 0¡ãC to +70¡ãC. This accuracy can also be achieved

by applying system calibration at +25¡ãC. The

MCP9700B can measure temperature with ¡À1¡ãC from

+20¡ãC to +70¡ãC 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.

Features

? Tiny Analog Temperature Sensor

? Available Packages:

- SC70-5, SOT-23-3, TO-92-3 (not available

with the MCP9700B)

? Wide Temperature Measurement Range:

- -40¡ãC to +125¡ãC (Extended Temperature)

- -40¡ãC to +150¡ãC (High Temperature)

(MCP9700 and MCP9700B, SOT-23-3 and

SC70-5 only)

? Accuracy:

- ¡À1¡ãC (max.), +20¡ãC to +70¡ãC (MCP9700B)

- ¡À2¡ãC (max.), 0¡ãC to +70¡ãC (MCP9700A/9701A)

- ¡À4¡ãC (max.), 0¡ãC to +70¡ãC (MCP9700/9701)

? Optimized for Analog-to-Digital Converters (ADCs):

- 10.0 mV/¡ãC (typical) (MCP9700/9700A/

9700B)

- 19.5 mV/¡ãC (typical) (MCP9701/9701A)

? Wide Operating Voltage Range:

- VDD = 2.3V to 5.5V (MCP9700/9700A/

9700B)

- VDD = 3.1V to 5.5V (MCP9701/9701A)

? Low Operating Current: 6 ¦ÌA (typical)

? Optimized to Drive Large Capacitive Loads

Typical Applications

? Automotive

? Hard Disk Drives and Other PC Peripherals

? Entertainment Systems

? Home Appliance

? Office Equipment

? Battery Packs and Portable Equipment

? General Purpose Temperature Monitoring