C8051T617-GM Silicon Laboratories Inc, C8051T617-GM Datasheet - Page 51

• Manufacturer Part Number: C8051T617-GM
• Description: IC 8051 MCU 16K BYTE-PROG 24-QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051T61xr

Specifications of C8051T617-GM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: OTP
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 24-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Other names: 336-1438-5

9. Temperature Sensor (C8051T610/1/2/3/6 only)
An on-chip temperature sensor is included on the C8051T610/1/2/3/6 which can be directly accessed via
the ADC multiplexer. To use the ADC to measure the temperature sensor, the ADC mux channel should be
configured to connect to the temperature sensor. The temperature sensor transfer function is shown in
Figure 9.1. The output voltage (V
The TEMPE bit in register REF0CN enables/disables the temperature sensor, as described in SFR Defini-
tion 10.1. While disabled, the temperature sensor defaults to a high impedance state and any ADC mea-
surements performed on the sensor will result in meaningless data. Refer to Table 7.9 for the slope and
offset parameters of the temperature sensor.
9.1. Calibration
The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature mea-
surements (see Table 7.9 on page 36 for specifications). For absolute temperature measurements, offset
and/or gain calibration is recommended. A single-point offset measurement of the temperature sensor is
performed on each device during production test. The registers TOFFH and TOFFL, shown in SFR Defini-
tion 9.1 and SFR Definition 9.2 represent the output of the ADC when reading the temperature sensor at 0
degrees Celsius, and using the internal regulator as a voltage reference.
Figure 9.2 shows the typical temperature sensor error assuming a 1-point calibration at 0 °C. Parameters
that affect ADC measurement, in particular the voltage reference value, will also affect temperature
measurement.
Figure 9.1. Temperature Sensor Transfer Function
V
Temp
TEMP
TEMP
C
=
= (V
) is the positive ADC input when the ADC multiplexer is set correctly.
(Slope
TEMP
x Temp
- Offset) /
Temperature
Rev 1.0
C8051T610/1/2/3/4/5/6/7
C
) +
Offset
Slope
Offset
(V at 0 Celsius)
Slope
(V / deg C)
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