Cirrus-logic AN366 Manuel d'utilisateur télécharger pdf (Page 46)

AN366

6.2.3 DC Offset Calibration Flow Diagram

The implemented of DC offset calibration follows the same structure as AC offset except that the voltage

and current source are both zero. The high pass filters must not be enabled and instead of sending AC Cal-

ibration command (F6), the DC Calibration command is sent (E6). Refer to the main flow for reading the DC

offset registers.

READ POWER REGISTERS

Reading IRMS is shown in main flow (see Figure 42).

SDI = 0x90 0x25 0xFFFFFF Read I1ACOFF (page 16, register 37)

SDO = 0xFF 0xFF 0x050704 (0.0392766)

SDI = 0x90 0x2C 0xFFFFFF Read I2ACOFF (page 16, register 44)

SDO = 0xFF 0xFF 0x049959 (0.0359298)

Figure 42. Conversion Window

PC/Controller tests for change in IACOFF register to check for success.

CHECK

INPUT

FAIL

RETURN

IACOFF

MAIN FLOW

IACOFF = 0?

AC OFFSET

CALIBRATION

COMPLETE

YES

READ IRMS,

IACOFF

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Cirrus-logic AN366 Manuel d'utilisateur Page 46