DS1113F1
27
CS4399
4.4 Headphone Presence Detect
• To avoid possible damage, VCP_FILT± pins must remain within the absolute maximum rating specified.
Figure 4-6. External VCP_FILT Power-Up Sequence
For powering up CS4399 in this mode, the recommended sequence must be followed. This assumes that the CS4399
starts from the status where VCP_FILT± pin are presented with Hi-Z.
1. Set EXT_VCPFILT.
2. Wait 8 ms after I
2
C ACK.
3. Release and start to ramp external voltage on VCP_FILT± pin.
4. Wait until V pin voltage to be greater than +2.6V and VCP_FILT– to be less than –2.6 V.
5. Clear the PDN_HP bit.
Figure 4-7. External VCP_FILT Power-Down Sequence
For powering down in this mode, use the following recommended sequence. This assumes that the CS4399 starts from
the status where VCP_FILT± pin are presented with ±3.0 V, respectively.
1. Execute the power down sequence per
2. Wait 8 ms after I
2
C ACK.
3. Start to shut-off external supply to VCP_FILT± pins.
4. Wait until Hi-Z mode is presented on VCP_FILT± pins.
5. Clear EXT_VCPFILT.
4.4
Headphone Presence Detect
The CS4399 provides headphone presence-detect functionality.
EXT_VCPFILT
PDN_HP
V
VCP_FILT
‐
8
ms
+3.0
V
‐
3.0
V
+2.6
V
‐
2.6
V
Hi
‐
Z
Hi
‐
Z
EXT_VCPFILT
PDN_HP
V
VCP_FILT
‐
8
ms
+3.0
V
‐
3.0
V
Hi
‐
Z
Hi
‐
Z