FSA4480
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24
APPLICATION INFORMATION
Over−Voltage Protection
FSA4480 features over−voltage protection (OVP) on
receptacle side pins that switches off the internal signal
routing path if the input voltage exceeds the OVP threshold.
If OVP is occurred, interrupt signal can be send by INT
signal and FLAG data will provide information that which
pin had OVP event.
Headset Detection
FSA4480 integrates headset unplug detection function by
detecting the CC_IN voltage. The function is always active
when device is enabling. DET will be high when CC_IN is
low (CC_IN < 1.2 V). When CC_IN = High (CC_IN > 1.5
V), DET will be released to low.
Device Disable Device Enable
CC_IN < V
TH_L
= 1.2 V DET = 0 DET = 1
CC_IN > V
TH_H
= 1.5 V DET = 0 DET = 0
MIC Switch Auto−off Function
The function is active during control bit 0x12h bit[2] = 1.
When CC_IN is high (CC_IN > 1.5 V) and L,R, Audio
ground switches are under on status, MIC switch will be off
and receptacle side pin will be connected to ground for 50 mS
first. Then it shows high−Z status under MIC switch is set on
status.
Audio Ground Detection and Configuration
The function is active when control bit 0x12h bit[0] = 1
and R, L AGND switches are set to be on status. For type−C
interface analog headset, the audio ground could be SBU1
pin or SBU2 pin. The function will provide autonomous
detection and configuration to route MIC and audio ground
signal accordingly.
Figure 4.
Audio Jack detection
and configuration Start
DATA0>=REG1
and
DATA0>=REG2
REG1>REG2>DATA0
&& REG2<DATA1
Or
REG1>DATA0>RGE2
REG2>REG1>DATA0
&& REG1<DATA1
Or
REG2>DATA0>REG1
REG2>= DATA1
and
REG1>=DATA1
Hold current setting
MIC to SBU2,
Audio ground to SBU1
Sense to GSBU1
send INT
MIC to SBU1,
Audio ground to SBU2
Sense to GSBU2
send INT
Audio ground to SBU1
Sense to GSBU1
SBU2 switch open
During detection and configuration, the R, L, Sense, MIC
and Audio ground switch will be off. After detection and
configuration, R and L switches will turn on according to
switch configuration and timing setting. MIC, Sense and
Audio ground will turn on according to detection results and
timing control setting.
