C8051F300 Silicon Laboratories Inc, C8051F300 Datasheet - Page 33

• Manufacturer Part Number: C8051F300
• Description: IC 8051 MCU 8K FLASH 11MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F30xr

Specifications of C8051F300

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 8
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 11-VQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

5.2.
The typical temperature sensor transfer function is shown in Figure 5.2. The output voltage (V
PGA input when the temperature sensor is selected by bits AMX0P2-0 in register AMX0SL; this voltage will be
amplified by the PGA according to the user-programmed PGA settings.
The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature measurements
(see Table 5.1 for linearity specifications). For absolute temperature measurements, gain and/or offset calibration is
recommended. Typically a 1-point 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 mea-
surement.
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 and GND
Step 4. Calculate the offset and/or gain characteristics, and store these values in non-volatile memory for
selected as the negative input.
use with subsequent temperature sensor measurements.
Figure 5.2. Typical Temperature Sensor Transfer Function
1200
1100
1000
(mV)
900
800
700
-50
0
Rev. 2.3
V
TEMP
50
= 3.35*(TEMP
C8051F300/1/2/3/4/5
C
100
) + 897 mV
(Celsius)
TEMP
) is the positive
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