C8051F340-GQR Silicon Laboratories Inc, C8051F340-GQR Datasheet - Page 43

• Manufacturer Part Number: C8051F340-GQR
• Description: MCU 8-Bit C8051F34x 8051 CISC 64KB Flash 3.3V/5V 48-Pin TQFP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051F340-GQR

• Package: 48TQFP
• Device Core: 8051
• Family Name: C8051F34x
• Maximum Speed: 48 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 40
• Interface Type: I2C/SMBus/SPI/UART/USB
• On-chip Adc: 17-chx10-bit
• Number Of Timers: 4
• Ram Size: 4.25 KB
• Program Memory Size: 64 KB
• Program Memory Type: Flash
• Operating Temperature: -40 to 85 °C

5.2.
The temperature sensor transfer function is shown in Figure 5.2. The output voltage (V
ADC input when the temperature sensor is selected by bits AMX0P4-0 in register AMX0P. Values for the
Offset and Slope parameters can be found in Table 5.1.
The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature mea-
surements (see Table 5.1 for linearity specifications). For absolute temperature measurements, offset and/
or gain calibration is recommended. Typically a 1-point (offset) calibration includes the following steps:
Figure 5.3 shows the typical temperature sensor error assuming a 1-point calibration at 25 °C. Note that
parameters which affect ADC measurement, in particular the voltage reference value, will also
affect temperature measurement.
Temperature Sensor
Step 1. Control/measure the ambient temperature (this temperature must be known).
Step 2. Power the device, and delay for a few seconds to allow for self-heating.
Step 3. Perform an ADC conversion with the temperature sensor selected as the positive input
Step 4. Calculate the offset characteristics, and store this value in non-volatile memory for use
and GND selected as the negative input.
with subsequent temperature sensor measurements.
Figure 5.2.
C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D
V
Temp
TEMP
C
=
= (V
Temperature Sensor Transfer Function
(Gain
TEMP
x Temp
- Offset) /
Temperature
Rev. 1.3
C
) +
Offset
Offset
Gain
(V at 0 Celsius)
Gain
(V / deg C)
TEMP
) is the positive
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