FS970X

Rev. 4.4

3/46

Contents

1.

GENERAL DESCRIPTION ......................................................................................................................... 5

2.

FEATURES................................................................................................................................................. 5

2.1

General Features (FS9701A/B as an example) ........................................................................... 5

2.2

Measurement Range (FS9701B as an example) ......................................................................... 6

3.

ORDERING INFORMATION....................................................................................................................... 6

4.

ELECTRICAL CHARACTERISTICS .......................................................................................................... 6

5.

BLOCK-DIAGRAM ..................................................................................................................................... 8

6.

PACKAGING & PINS ................................................................................................................................. 8

6.1

LQFP 64 Pin Definition.................................................................................................................. 8

6.2

Pin Description.............................................................................................................................. 9

7.

TYPICAL APPLICATION CIRCUIT .......................................................................................................... 10

8.

REGULATOR............................................................................................................................................ 11

8.1

Low Voltage Detector.................................................................................................................. 12

8.2

Saving Mode ................................................................................................................................ 12

8.3

On/Off Power Output .................................................................................................................. 13

9.

CLOCK AND BUZZER GENERATOR...................................................................................................... 14

9.1

Clock Generator .......................................................................................................................... 14

9.2

Buzzer Generator ........................................................................................................................ 15

10. FUNCTION NETWORK ............................................................................................................................ 16

10.1

Function Decoder........................................................................................................................ 17

10.2

Fixed Voltage Generator ............................................................................................................. 18

10.3

Ω Power Supply ..........................................................................................................................19

10.4

Multiplexers and pre-filter .......................................................................................................... 20

10.5

Operation Amplifier and Comparator ........................................................................................ 22

11. ANALOG TO DIGITAL CONVERTER (ADC) ........................................................................................... 24

11.1

The operating theory of

- ADC ...............................................................................................24

11.2

Transfer Function & Non-ideal affect ........................................................................................ 24

11.3

Function Gain Setup ................................................................................................................... 25

11.4

Digital Filter ................................................................................................................................. 26

11.5

Reading and operation of ADC .................................................................................................. 28

11.5.1 High-resolution, low-speed output ............................................................................................ 28

11.5.2 Low-resolution, high-speed output ........................................................................................... 28

11.5.3 Scale-type resistance measurement and Analog Bargraph .................................................... 29