CS43130 Datasheet, PDF (33/137 Pages) Cirrus Logic – 130-dB, 32-Bit High-Performance DAC with Integrated Headphone Driver

CS43130
4.5 Headphone Presence Detect and Output Load Detection
Before opening the HPINx switches, ramp down any active signal on HPINx pins to a voltage less than the V_INOFF value
specified in Table 3-7. Similarly, the voltage cannot exceed the same voltage requirement before the switches are closed.
To prevent any pop on the headphone, the input should be muted during these transition. The CS43130 has ultralow offset
when muted. For pop-free transition on the headphone, it is expected that the source on HPINx pins have low offset to
ground when muted.
The recommended sequence to switch from CS43130 to HPINx is as follows:
1. Soft ramp content on CS43130 down to mute.
2. Set PDN_HP and wait for PDN_DONE_INT event.
3. If saving power is desired, switch MCLK_INT source to RCO.
4. Enable HPINx path.
The recommended sequence to switch from HPINx to CS43130 is as follows:
1. Setup CS43130 intended MCLK source for DAC operation (if needed)
2. Soft ramp content on HPINx down to mute.
3. Disable HPINx path.
4. Switch MCLK_INT to the intended MCLK source when ready.
5. Clear PDN_HP.
4.5 Headphone Presence Detect and Output Load Detection
The CS43130 provides headphone presence-detect and load-detection functionalities functionality.
4.5.1 Headphone Presence Detect
The CS43130 supports headphone presence-detect capability via the HP_DETECT sense pin. HP_DETECT is
debounced to filter out brief events before being reported to the corresponding presence-detect status bit and generating
an interrupt if appropriate.
4.5.1.1 Headphone Plug Types
The presence detect scheme is designed to support the following plug types:
• Tip-Ring-Sleeve (TRS). Consists of a segmented metal barrel with the tip connector used for HPOUTA, a ring
connector used for HPOUTB, and a sleeve connector used for HPGND.
• Tip-Ring-Ring-Sleeve (TRRS). Similar to TRS, with an additional ring connector for the HSIN connection. There are
two common pinouts for TRRS plugs:
— The tip is used for HPOUTA, the first ring for HPOUTB, the second ring for HSGND, and the sleeve for HSIN.
— An alternate pinout, OMTP (open mobile terminal platform), also called “China headset,” swaps the third and
fourth connections so that the second ring carries HSIN and the sleeve carries HSGND.
Note that if both TRRS plug types need to be supported at the same time, the CS43130 requires an additional IC to perform
the OMTP detect functions and to present the identified HSGND to the CS43130 HPREFx. However, the switch inside the
detect IC may degrade the CS43130 performance.
4.5.1.2 Headphone Detect Methods
CS43130 can detect the presence or absence of a plug. For a headphone-presence detect, a sense pin is connected to
a terminal on the receptacle such that, if no plug is inserted, the pin is floating. If a plug is inserted, the pin is shorted to
the tip (T) terminal. The presence detect function is accomplished by having a small current source inside the CS43130
to pull up the pin if it is left floating (no plug). If a plug is inserted and the sense pin is shorted to HPOUTA, when HP amp
is powered down, it is assumed that the sense pin is pulled low via clamps at the HP amp output. If the HP amp is running,
DS1073F1
33