Cirrus Logic CDB5480U, General Description Manual

Page: 26 / 47

CDB5480U
26 DS893DB5
2.6.3 Performing Calibrations
AC/DC offset and gain calibrations can be performed on both the voltage and current channels of the
CS5480. It is generally a good idea to software-reset the CS5480 before running calibrations, because
the initial values in the calibration registers will affect the results of the calibration. A software reset will
reset these registers back to the default values of zero offset and unity gain. AC/DC offset calibration
should be performed before gain calibration to ensure accurate results.
2.6.3.1 Offset Calibrations
1. Ground the channel(s) you want to calibrate directly at the channel header(s), J6 and J10 for the voltage
channel and J7, J8, J13, and J14 for the current channels. The channel(s) could also be grounded directly
at the screw-type terminals.
2. Press the corresponding AC or DC offset calibrate button ( Cal V , Cal I , or Calibrate All Channels ) in the cor-
responding Offset Calibration box(es).
3. The offset register value(s) will automatically update when the calibration is completed.
2.6.3.2 Gain Calibrations
1. Attach an AC or DC calibration signal to the screw-type terminals, and make sure the corresponding chan-
nel headers (J6, J7, J8, J10, J13, and J14) are set to the desired input position.
2. Press the corresponding gain calibrate button ( Cal V , Cal I , or Calibrate All Channels ) in the corresponding
Gain Calibration box(es).
3. The gain register value(s) will automatically update when the calibration is completed.
The Calibration window also contains the Active and Reactive Power Offset Register 1 and Register 2
display and adjustment. The user can read and write the values in the CS5480 active and reactive power
offset registers (P1
OFF
, P2
OFF
, Q1
OFF
, and Q2
OFF
).