Rainbow Electronics MAX98089 - Manual (Page 114)

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MAX98089
Low-Power, Stereo Audio Codec
with FlexSound Technology
Jack Detection
The IC features jack detection that can detect the insertion
and removal of a jack as well as the load type. When a jack
is detected, an interrupt on IRQ can be triggered (by set-
ting IJDET). to alert the microcontroller of the event. Figure
33 shows the typical configuration for jack detection.
Jack Insertion
To detect a jack insertion, the IC must have a power
supply. Set JDETEN to enable jack detection circuitry
and apply a pullup current to JACKSNS. Set JDWK to
minimize supply current. Jack insertion can be done in
shutdown or out of shutdown. Clear JDWK to differentiate
between headsets with a microphone and headphones
without a microphone. The voltage on JACKSNS is equal
to SPKLVDD as long as no load is applied to JACKSNS
and MICBIAS is disabled. Table 31 shows the change in
JKSNS that occurs when a jack is inserted.
Accessory Button Detection
After jack insertion, the MAX98089 can detect button
presses on accessories that include a microphone and
a switch that shorts the microphone signal to ground.
Set JDETEN to enable jack detection circuitry. Button
presses can be detected both when MICBIAS is enabled
and disabled. Table 32 shows the change in JKSNS that
occurs when the accessory button is pressed.
Jack Removal
The IC detects jack removal by monitoring JACKSNS for
transitions to the 11 state. Set JDETEN to enable jack
detection circuitry. Set JDWK to minimize supply current
if button detection is not required. Table 33 shows the
change in JKSNS that occurs when a jack is removed.
Jack removal can be done in shutdown or out of shutdown.
Figure 33. Typical Configuration for Jack Detection
Table 31. Change in JKSNS Upon Jack Insertion
Table 32. Change in JKSNS Upon Button Press
JACKSENSE
MICBIAS
MIC1P OR MIC2P
HPL
HPR
2.2kI
HPL GND HPR
MIC HPL GND HPR
HPL GND HPR
JACK TYPE JDWK = 1 JDWK = 0
JKSNS: 11 è 00 JKSNS: 11 è 00
JKSNS: 11 è 00 JKSNS: 11 è 01
JACK TYPE MICBIAS ENABLED OR DISABLED
JKSNS: 01 и 00