CS5461
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
2
DS546F2