C8051F962-A-GM Silicon Labs, C8051F962-A-GM Datasheet - Page 97

• Manufacturer Part Number: C8051F962-A-GM
• Description: 8-bit Microcontrollers - MCU 128KB, DC-DC, AES DQFN76
• Manufacturer: Silicon Labs

Specifications of C8051F962-A-GM

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8448 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.5 V to 3.3 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: DQFN-76
• Mounting Style: SMD/SMT
• Number Of Programmable I/os: 57
• Number Of Timers: 4

5.8. Temperature Sensor
An on-chip temperature sensor is included on the C8051F96x which can be directly accessed via the ADC
multiplexer in single-ended configuration. To use the ADC to measure the temperature sensor, the ADC
mux channel should select the temperature sensor. The temperature sensor transfer function is shown in
Figure 5.8. The output voltage (V
The TEMPE bit in register REF0CN enables/disables the temperature sensor, as described in SFR
Definition 5.15. REF0CN: Voltage Reference Control. While disabled, the temperature sensor defaults to a
high impedance state and any ADC measurements performed on the sensor will result in meaningless
data. Refer to Table 4.12 for the slope and offset parameters of the temperature sensor.
5.8.1. Calibration
The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature mea-
surements (see Table 4.13 for linearity specifications). For absolute temperature measurements, offset
and/or gain calibration is recommended. Typically a 1-point (offset) calibration includes the following steps:
1. Control/measure the ambient temperature (this temperature must be known).
2. Power the device, and delay for a few seconds to allow for self-heating.
3. Perform an ADC conversion with the temperature sensor selected as the positive input and GND
4. Calculate the offset characteristics, and store this value in non-volatile memory for use with
selected as the negative input.
subsequent temperature sensor measurements.
Figure 5.8. Temperature Sensor Transfer Function
Temp
V
TEMP
TEMP
C
=
= 25 + (
) is the positive ADC input when the ADC multiplexer is set correctly.
Slope
V
x (Temp
TEMP
Rev. 0.5
Temperature
- Offset) /
C
Offset
- 25) +
( V at 25 Celsius)
Slope
Offset
Slope
( V / deg C)
C8051F96x
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