User's Manual

RYZ012 Multi-Standard Wireless Communication Module for Bluetooth 5 Low Energy and 802.15.4
R15UH0002EU0103 Rev.1.03 Page 179 of 206
Apr.21.21
16. Temperature Sensor
The RYZ012 integrates a temperature sensor and it is used in combination with the SAR ADC to detect real-time temperature.
The temperature sensor is disabled by default. The analog register SCTL:PDC1:TSPD must be cleared to enable the temperature sensor. The
temperature sensor embeds two diodes. It takes the real-time temperature (T) as input, and outputs two-way forward voltage drop (V
BE
) signals
of diodes as positive and negative output respectively.
Figure 34. Block Diagram of Temperature Sensor
The difference of the two-way V
BE
signals (V
BE
) is determined by the real-time temperature T, as shown below: V
BE
= 130mV + 0.51mV / °C *
( T - ( -40°C ) ) = 130mV + 0.51mV / °C * ( T + 40°C )
In this formula, "130mV" indicates the value of V
BE
at the temperature of "-40°C".
To detect the temperature, the positive and negative output of the temperature sensor should be enabled as the input channels of the SAR
ADC. The ADC will convert the two-way V
BE
signals into digital signal.
When the ADC is configured in differential mode, the positive and negative output of the temperature sensor should be configured as differential
input of the ADC. The ADC should initiate one operation and obtain one output signal (ADCOUT); therefore,
V
BE
= ADCOUT /( 2
N
- 1 ) * V
REF
.
In the formula, N and V
REF
indicate the selected resolution and reference voltage of the SAR ADC.
Then the real-time temperature T can be calculated according to the V
BE
.