CS43130 Datasheet, PDF (83/137 Pages) Cirrus Logic – 130-dB, 32-Bit High-Performance DAC with Integrated Headphone Driver

CS43130
5.11 Headphone Load Measurement
5.11.1 Enabling the Impedance Measurement Subsystem
Fig. 5-2 shows and Ex. 5-20 describes the steps necessary for enabling the impedance measurement subsystem.
Enable Impedance Measurement
Subsystem
Device is powered up and out of reset.
MCLK_SRC_SEL = 00 or 01 (MCLK/XTAL or PLL)
HP_IN_ EN = 0 (HPIN disabled)
HPDETECT_PLUG _INT = 1 (Headphone present )
HPLOAD _EN = 0 ( Impedance measurement sub-system is turned off)
PDN_HP = 1
?
NO
YES
Perform Headphone Power
Down Sequence
Read Interrupt Status 4
Enable HPLOAD Interrupts
HPLOAD _NO_DC_INT_MASK= 0
HPLOAD_UNPLUG_ INT_MASK = 0
HPLOAD_OOR _INT_MASK = 0
HPLOAD_DC_DONE_INT_MASK = 0
HPLOAD_AC_ DONE_INT_MASK = 0
HPLOAD_ OFF_INT_ MASK = 0
HPLOAD _ON_INT_MASK = 0
Enable calibration
0x10010 = 0x99
0x80024 = 0xBB
0x1002 C = 0x01
0x10027 = 0x95
0x10028 = 0x0 B
0x100010 = 0x00
Enable Impedance Measurement
Sub-System
HPLOAD_EN = 1
HPLOAD_ AC_ START = 0
HPLOAD_DC_START = 0
HPLOAD_ ON_INT
NO
= 1?
YES
DC Impedance Measurement
Or
AC Impedance Measurement
Figure 5-2. Enabling the Impedance Measurement Subsystem Flowchart
Example 5-20. Sequence for Enabling the Impedance Measurement Subsystem
STEP
TASK
1 If PDN_HP = 1, go to Step 3.
REGISTER/BIT FIELDS
VALUE
DESCRIPTION
2 Power down headphone output. See headphone power down sequence in Section 5.7, “Headphone Power Down Sequences.”
3 Measure headphone DC impedance
DS1073F1
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