11..3

AGND Generator

600K

ENGNDB

10uF

AGND

600K

VDD

VSSA

VSSA

AGND is analog common voltage. When ENGNDB=0, analog common voltage generator will active.

11..4

Bandgap Voltage Reference and Temperature sensor

.

AGND

70K

Voltage Reference

and

Temperature Sensor

TEMPL

TEMPH

ENREF

REFO

50K

REFI

REFO is low temperature coefficient bandgap voltage reference output. When ENBAND=1, the circuit will

active. The output voltage to AGND is about 1.2V. Typical temperature coefficient is 100ppm/℃.

{TEMPH, TEMPL} is proportion to ambient temperature. You can select them to ADC input and transfer to

digital code. (Typical 500uV±50uV/℃)

11..5

Bias Current Source Generator

REFO

(1.2V)

AGND

VSS

3uA

400K

ENGNDB

The bias current for all the analog circuits of FS511. If the embedded op amp works, REFO will be pulled to

AGND by the feedback; there are 1.2V in resistor 400K, and 3uA bias current can be obtained.