CS5461

2

DS546F2

TABLE OF CONTENTS

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

2. PIN DESCRIPTION ................................................................................................................... 6

3. CHARACTERISTICS/SPECIFICATIONS ................................................................................. 8

ANALOG CHARACTERISTICS ................................................................................................ 8

VOLTAGE REFERENCE........................................................................................................ 10

5 V DIGITAL CHARACTERISTICS......................................................................................... 11

3 V DIGITAL CHARACTERISTICS......................................................................................... 11

SWITCHING CHARACTERISTICS ........................................................................................ 13

3.1 Theory of Operation ......................................................................................................... 13

3.1.1 High-Rate Digital Low-Pass Filters ..................................................................... 15

3.1.2 Digital Compensation Filters ............................................................................... 15

3.1.3 Digital High-Pass Filters ...................................................................................... 15

3.1.4 Gain and DC Offset Adjustment .......................................................................... 15

3.1.5 Average (Real) Power Computation ................................................................... 15

3.1.6 RMS Computations ............................................................................................. 16

3.2 Performing Measurements ............................................................................................... 16

3.3 CS5461 Linearity Performance ........................................................................................ 16

4. FUNCTIONAL DESCRIPTION ............................................................................................... 17

4.1 Analog Inputs ................................................................................................................... 17

4.2 Voltage Reference ........................................................................................................... 17

4.3 Oscillator Characteristics .................................................................................................17

4.4 Calibration ........................................................................................................................ 18

4.4.1 Overview of Calibration Process ......................................................................... 18

4.4.2 Calibration Sequence .......................................................................................... 18

4.4.3 Calibration Signal Input Level ............................................................................. 18

4.4.4 Calibration Signal Frequency .............................................................................. 18

4.4.5 Input Configurations for Calibrations ................................................................... 18

4.4.6 Description of Calibration Algorithms .................................................................. 19

4.4.6.1 AC Offset Calibration Sequence ......................................................... 19

4.4.6.2 DC Offset Calibration Sequence ......................................................... 19

4.4.6.3 AC Gain Calibration Sequence ........................................................... 19

4.4.6.4 DC Gain Calibration Sequence ........................................................... 20

4.4.7 Duration of Calibration Sequence ....................................................................... 20

4.4.8 Order of Calibration Sequences .......................................................................... 21

4.5 Power Offset .................................................................................................................... 21

4.6 Phase Compensation ....................................................................................................... 21

4.7 Time-Base Calibration ..................................................................................................... 22

4.8 On-Chip Temperature Sensor .......................................................................................... 22

4.9 Interrupt ........................................................................................................................... 22

4.9.1 Typical use of the INT pin ................................................................................... 22

4.9.2 INT Active State .................................................................................................. 23

4.10 Voltage Sag-Detect Feature .......................................................................................... 23

5. ENERGY PULSE OUTPUTS .................................................................................................. 24

5.1 Pulse-Rate Output (EOUT and EDIR) ............................................................................. 24

5.2 Pulse Output for Normal Format, Stepper Motor Format and Mechanical

Counter Format ............................................................................................................ 24

5.2.1 Normal Format .................................................................................................... 24

5.2.2 Mechanical Counter Format ................................................................................ 25

5.2.3 Stepper Motor Format ......................................................................................... 25

5.3 FOUT Pulse Output ......................................................................................................... 25

5.4 Anti-Creep for the Pulse Outputs ..................................................................................... 26

5.5 Design Examples ............................................................................................................. 26