Datasheet

FS98O22
Rev. 1.6 39/146
4.6. Bandgap Voltage and Temperature Sensor
Figure 4-7 Bandgap voltage and temperature sensor function block
REFO is low temperature coefficient bandgap voltage reference output. Its voltage to AGND is 1.16V, and the
typical temperature coefficient is 150ppm/°C.
FS98O22 embeds a Temperature Sensor to measure the IC temperature from the differential voltage between
TEMPH and TEMPL (typically 550μV±50μV/°C). Its working range is 100 ~ 200 mV. User can connect the
TEMPH and TEMPL to an ADC to get the IC temperature. Please refer to Chapter 10 and Chapter 11 for
detailed instruction of ADC.
Both the bandgap Voltage Reference and the Temperature sensor are controlled by ENBAND register flag.
Please see Figure 4-7.
Table 4-9 bandgap voltage and temperature sensor register table
Address Name
Referenced
Section
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on Power
on Reset
1DH NETF 4/10/11
ENBAND ENVDDA ENAGND ENVB
00000000
Operation:
1. Operate as Section 4.1 to get the VGG (2 times VDD or external Power Supply).
2. Operate as Section 4.2 to get the VDDA (3.6V)
3. Operate as Section 4.3 to enable the Analog Bias Circuit
4. Set the ENBAND register flag.
5. Check REFO. Its value with respect to AGND should be about 1.16V
6. The output, TEMPH and TEMPL, will show the IC temperature as the differential voltage.
FORTUNE'
Properties
For Reference Only