SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 109
Version 1.7
13.5 Temperature Sensor (TS)
In applications, sensor characteristic might change in different temperature also. To get the temperature information,
SN8P2977 build in a temperature senor (TS) for temperature measurement. Select the respective PGIA channel to
access the Temperature Sensor ADC output.
AVSS
AVDDR
TS +
ΔΣ ADC
X+
X-
PGIA
ADCDH,M,L
(24-Bit)
PGIA
Off
PGIA
Off
TS -
TS - : Voltage division from VBG
MUXN[2:0] = 110
MUXP[2:0] = 110
Gain=1x1,AMPEN = 0
Temperature senor setting table:
Note 1: When selected Temperature Sensor, PGIA gain must set to 1x, or the result will be incorrect.
Note 2: Under this setting, X+ will be the V(TS) voltage, and X- will be VBG.
Note 3: The Temperature Sensor was just a reference data not real air temperature. For precision
application, please use external thermistor sensor.
In 25C, V(TS) will be about 1.056V typically, and if temperature rise 10
℃
, V(TS) will decrease about 17.0mV, if
temperature drop 10
℃
, V(TS) will increase about 17.0mV.
Example:
Temperature
V(TS)
Vref = (VBG*2/3)
16-Bit ADC output
15
℃
V
TS
17mV
0.8V
9635
25
℃
V
TS
Offset
8972
35
℃
V
TS
Offset - 17mV
8309
※
By ADC output of V(TS), can get temperature information and compensation the system.
Example: If temperature 25°C ADC Cnt about 8972, when measured ADC CNT=9635, what's the
temperature now?( Slope:-65 Cnt/
℃
)
Temperature value = 25
℃ +
(Measure
ADC CNT - 25
℃
ADC CNT) / Slope
= 25
℃ +
(9635 - 8972) / -65
≈ 15
℃
Note 1: The V(TS) voltage and temperature curve of each chip might different. Calibration in room
temperature is necessary when application temperature sensor.
Note 2: -1.70mV/C was typical temperature parameter only sensor, every single chip was different to each
other.
IRVS[3:0]
Vref source
(VBG*2/3)
16Bit-ADC
10xx
0.8V
-65 AD Cnt/
℃