Contents

1.

INTRODUCTION TO FS501 CHIP.............................................................................................................. 5

1.1

Characteristics .............................................................................................................................. 5

1.2

Block Diagram of FS501 ............................................................................................................... 6

2.

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

3.

PACKAGE AND TERMINAL ASSIGNMENTS ........................................................................................... 8

3.1

Package and Terminal Assignment of LQFP44 .......................................................................... 8

3.2

Terminal Description................................................................................................................... 10

4.

MICROPROCESSOR INTERFACES ....................................................................................................... 11

4.1

Control Registers ........................................................................................................................ 11

4.2

Interrupt Process ........................................................................................................................ 12

4.3

Measure Registers ...................................................................................................................... 13

5.

VOLTAGE REGULATOR .......................................................................................................................... 14

5.1

Bias Current Source Generator ................................................................................................. 14

5.2

Power Saving Mode .................................................................................................................... 15

5.3

Switchable Power Output ........................................................................................................... 15

5.4

Power Low Detector.................................................................................................................... 16

6.

CLOCK GENERATOR.............................................................................................................................. 16

6.1

Clock Generator .......................................................................................................................... 16

7.

FUNCTION NETWORK ............................................................................................................................ 18

7.1

Measure Mode ............................................................................................................................. 19

7.2

Multiplexer and Pre-filter ............................................................................................................ 20

7.3

Operation Amplifier (Op Amp).................................................................................................... 20

7.4

Ohm Voltage Source ................................................................................................................... 21

8.

ANALOG TO DIGITAL CONVERTER (ADC) ........................................................................................... 22

8.1

The Operation of the Delta-Sigma (

) Modulator ADC ...........................................................22

8.2

Gain Stage Setting ...................................................................................................................... 22

8.3

Digital Filter ................................................................................................................................. 24

8.4

Reading and Calculating of Digital-to-Analog Converter ........................................................ 25

8.5

The Conversion of the Digital Codes and Equivalent Voltage................................................. 26

8.6

Other Control Setting.................................................................................................................. 26

9.

APPLICATION INFORMATION ................................................................................................................ 27

9.1

Application Circuit of Electronics Scale (Using Internal OP) .................................................. 27

9.2

Application Circuit of Electronics Scale (Using External OP)................................................. 28