WM5102 datasheet(185/334 Pages) WOLFSON

185 / 334 page

Production Data

WM5102

PD, June 2014, Rev 4.2

185

The timing of the microphone detect function is illustrated in Figure 65. Two different cases are

shown, according to whether MICBIASn is enabled periodically by the impedance measurement

function (MICBn_ENA=0), or is enabled at all times (MICBn_ENA=1).

Figure 65 Microphone and Accessory Detect Timing

HEADPHONE DETECT

The WM5102 headphone detection circuit measures the impedance of an external headphone load.

This feature can be used to set different gain levels or to apply other configuration settings according

to the type of load connected. Separate monitor pins are provided for headphone detection on the left

and right channels of HPOUT1.

Headphone detection may only be selected on one channel at a time. The available channels are the

HPDETL pin or the HPDETR pin. The selected channel is determined by the ACCDET_MODE

The WM5102 can only support one headphone or microphone detection function at any time. When

the detection function is not in use, it is recommended to set ACCDET_MODE=00.

Headphone detection on the selected channel is commanded by writing a ‘1’ to the HP_POLL register

bit. The impedance measurement range is configured using the HP_IMPEDANCE_RANGE register.

Note that a number of separate measurements (for different impedance ranges) is typically required in

order to determine the load impedance; the recommended control sequence is described below.

For correct operation, the respective output driver(s) must be disabled when headphone detection is

commanded on HPOUT1L or HPOUT1R. The applicable ground clamp must also be disabled. These

requirements are detailed in Table 77.

WM5102 Datasheet(PDF) 185 Page - Wolfson Microelectronics plc