C8051F351 Silicon Laboratories Inc, C8051F351 Datasheet - Page 71

• Manufacturer Part Number: C8051F351
• Description: IC 8051 MCU 8K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F35xr

Specifications of C8051F351

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 50MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 17
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x24b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

8.
The temperature sensor system consists of two diodes with different temperature properties and two con-
stant current sources. The two channels are connected to the ADC inputs internally, using the ADC’s ana-
log multiplexer. The temperature sensor system can be used in a single-ended or differential mode, to
measure the temperature of the C8051F350/1/2/3. Single channel measurements produce more output
voltage per degree C, but are not as linear as differential measurements. See Table 8.1 for temperature
sensor electrical characteristics.
The temperature sensor channels are automatically enabled when they are selected by the ADC multi-
plexer. To use the temperature sensor for a single-channel measurement, the ADC multiplexer should be
configured with one channel connected to the temperature sensor, and the other connected to AGND. For
a differential measurement, the temperature sensor should be selected for both ADC channels.
The transfer functions for single-channel and differential measurements are shown in Figure 8.2 and
Figure 8.3, respectively. For slope and offset values, refer to Table 8.1.
V
Linearity
Offset (Note 1)
Slope (Note 1)
AV+ Supply Current
Note 1: Represents one standard deviation from the mean.
DD
= 3.0 V; -40 to +85 °C unless otherwise specified
Parameter
Temperature Sensor
Table 8.1. Temperature Sensor Electrical Characteristics
Figure 8.1. Temperature Sensor Block Diagram
Single Channel Measurement
Differential Measurement
AIN+ Channel Measurement, Temp = 0 °C
Differential Measurement, Temp = 0 °C
AIN+ Channel Measurement
Differential Measurement
Single Channel Measurement
Differential Measurement
Channel
AIN+
AGND
Conditions
AV+
Rev. 0.4
Channel
AIN-
To AIN+ Mux
To AIN- Mux
C8051F350/1/2/3
Min
-1.73
54.3
Typ
757
205
10
20
Max
mV/°C
uV/°C
Units
mV
mV
µA
µA
°C
°C
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