Physical jitter between the plug and interface during headset insertion/removal causes voltage fluctuations on the detection pin; debouncing filters this interference to prevent false triggers and ensure accurate and stable detection. TAC5212 & TAC5112-Q1 integrates a debounce function for headset detection, enabling accurate detection of the headset type under scenarios with normal insertion and removal speeds. The debounce time can be set by JACK_DET_CFG2 Register (Page 1, Reg 0x1B).

Figure 2-17 Headset Insert Detection Debounce Configuration

DET_PULSE, which is generated using an internal oscillator, is used for hook button detection. DET_PULSE frequency is 0.5HZ,1Hz,7.5Hz or 15Hz based on reg map control with the high time of 4 or 32ms based on capacitor value on MICBIAS. If the hook button detection needs to be more sensitive, the detection frequency can be increased.

Figure 2-18 Pulse Scheme

Figure 2-19 Detection Pulse Setting Register

The JACK_DET_CFG1 register is used to control the enablement of headset detection, the coupling type setting for headphone detection, and the hook press detection setting.

Figure 2-20 Headset Detection Enable and Coupling Type Setting Register

Headset Detection result will update in JACK_DET_CFG2 Register (Address = 0x1B):

Figure 2-21 Headset Detection Result Indicator Register

The way the headset detection scheme works is it detects the insertion first, then starts the Headphone detection with debounce, after the headphones are confirmed, it goes about detecting microphones. Ones this is done an interrupt is generated. Then the flags can be read for status.

After the insertion interrupt is raised, there are no further checks on the type of jack. Headphone type detection is ONE time, during insertion and not real time.

The insertion, removal, and button press status of the headset are detected in real time; while the headset type detection (e.g., stereo headset, mono headset, stereo headset with microphone, mono headset with microphone) is a one-time detection, which is only updated when the headset is inserted, and the detection result is automatically cleared after removal. In addition, the button press detection function is only activated when a headset with a microphone is detected.