SI4431-A0-FM Silicon Laboratories Inc, SI4431-A0-FM Datasheet - Page 60

• Manufacturer Part Number: SI4431-A0-FM
• Description: IC TXRX ISM 930MHZ 3.6V 20-QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4431-A0-FM

• Package / Case: 20-QFN
• Mfg Application Notes: Transitioning SI4430/31 to Rev B
• Frequency: 240MHz ~ 930MHz
• Data Rate - Maximum: 128kbps
• Modulation Or Protocol: FSK, GFSK, OOK
• Power - Output: 13dBm
• Sensitivity: -118dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 18.5mA
• Current - Transmitting: 28mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 2
• Number Of Transmitters: 1
• Wireless Frequency: 240 MHz to 930 MHz
• Output Power: 13 dBm
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Maximum Supply Current: 28 mA
• Minimum Operating Temperature: - 40 C
• Modulation: FSK, GFSK, OOK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Memory Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 336-1633-5

Si4431
8.4. Temperature Sensor
An analog temperature sensor is integrated into the chip. The temperature sensor will be automatically enabled
when the temperature sensor is selected as the input of the ADC or when the analog temp voltage is selected on
the analog test bus. The temperature sensor value may be digitized using the general-purpose ADC and read out
over the SPI through "Register 10h. ADC Sensor Amplifier Offset". The range of the temperature sensor is
selectable to configure to the desired application and performance. The table below demonstrates the settings for
the different temperature ranges and performance.
To use the Temp Sensor:
1. Set input for ADC to be Temperature Sensor, "Register 0Fh. ADC Configuration"—adcsel[2:0] = 000
2. Set Reference for ADC, "Register 0Fh. ADC Configuration"—adcref[1:0] = 00
3. Set Temperature Range for ADC, "Register 12h. Temperature Sensor Calibration"—tsrange[1:0]
4. Set entsoffs = 1, "Register 12h. Temperature Sensor Calibration"
5. Trigger ADC Reading, "Register 0Fh. ADC Configuration"—adcstart = 1
6. Read-out Value—Read Address in "Register 11h. ADC Value"
Control to adjust the temperature sensor accuracy is available by adjusting the bandgap voltage. By enabling the
envbgcal and using the vbgcal[3:0] bits to trim the bandgap the temperature sensor accuracy may be fine tuned in
the final application. The slope of the temperature sensor is very linear and monotonic but the exact accuracy or
offset in temperature is difficult to control better than ±10 °C. With the vbgtrim or bandgap trim though the initial
temperature offset can be easily adjusted and be better than ±3 °C.
The different ranges for the temperature sensor and ADC8 are demonstrated in Figure 27. The value of the ADC8
may be translated to a temperature reading by ADC8Value x ADC8 LSB + Lowest Temperature in Temp Range.
For instance for a tsrange = 00, Temp = ADC8Value x 0.5 – 64.
60
Add R/W Function/Description
12
13
*Note: Absolute temperature mode, no temperature shift. This mode is only for test purposes. POR value of
R/W
R/W Temperature Value Offset
entoff
0*
1
1
1
1
EN_TOFF is 1.
Sensor Control
Temperature
tsrange[1]
0
0
1
1
1
Table 23. Temperature Sensor Range
tsrange[0]
tsrange[1]
tvoffs[7]
D7
0
1
0
1
0
tsrange[0]
Preliminary Rev. 0.4
tvoffs[6]
D6
Temp. range
–64 … 192
–40 … 216
–64 … 64
0 … 128
0 … 341
entsoffs
tvoffs[5]
D5
entstrim
tvoffs[4]
D4
Unit
°C
°C
°C
°F
°K
vbgtrim[3] vbgtrim[2] vbgtrim[1] vbgtrim[0]
tvoffs[3]
D3
8 mV/°C
4 mV/°C
8 mV/°C
4 mV/°F
3 mV/°K
tvoffs[2]
Slope
D2
tvoffs[1]
D1
ADC8 LSB
tvoffs[0]
1.333 °K
D0
0.5 °C
0.5 °C
1 °C
1 °F
POR Def.
20h
00h