MAX98090AETL+ Maxim Integrated, MAX98090AETL+ Datasheet - Page 144

• Manufacturer Part Number: MAX98090AETL+
• Description: Interface - CODECs 5V 130mW Stereo Headphone Amp
• Manufacturer: Maxim Integrated

Specifications of MAX98090AETL+

• Rohs: yes

MAX98090
Table 76. Jack Detection Status Results
Jack Detection Internal Comparators
When enabled, the device detects jack insertion and
removal by monitoring the voltage on JACKSNS with two
internal comparators. The load sense comparator has a
95% threshold of the reference supply and is used to deter-
mine whether or not a jack has been inserted or removed.
The jack sense comparator has a threshold of 10% of the
reference supply, and is used to identify the type of jack
(headphones/headset) inserted (Table 78).
When a jack is not inserted (open), the pullup resistance
conducts high. In this state, V
sense comparator threshold and LSNS is set high to
indicate that no jack is inserted. When a jack is inserted
it loads JACKSNS and pulls the voltage below the load
sense comparator threshold. LSNS is then set low to indi-
cate that a jack is now inserted. When the jack is removed,
the pullup resistance once again conducts high and LSNS
is set high to indicate that the jack was removed.
When a jack is inserted, the loading on JACKSNS pulls
the voltage below the load sense comparator threshold.
However, depending on the type of jack connected the
voltage may or may not be pulled below the jack sense
comparator threshold. If a headphone jack is inserted
(3 pole), JACKSNS is shorted to ground. This pulls the
voltage below the jack sense comparator threshold
www.maximintegrated.com
V
TH_10%
V
V
JACKSNS VOLTAGE
TH_95%
JACKSNS
≤ V
No condition
JACKSNS
≤ V
< V
JACKSNS
TH_10%
< V
JACKSNS
TH_95%
is above the load
LSNS
1
0
0
1
(10% of the reference supply) and JKSNS is set low to
indicate headphones are inserted. If instead, a headset
jack is inserted (4 pole, as shown in Figure 44), instead
JACKSNS is biased to a voltage somewhere between the
referenced supply and ground. In this case, V
above the jack sense comparator threshold but below the
load sense comparator threshold. This state indicates that
a headset is inserted. Table 76 details the three possible
jack detection status results.
These comparators are only active when the JDETEN is
set high. When jack detection is disabled, JACKSNS is
in a high impedance state and the interface is completely
shut down. When the device is in shutdown and JDETEN
is low, LSNS and JKSNS retain their previous state
regardless of the jack status.
Jack Detection Programmable Debounce
The load sense and jack sense comparators also have a
programmable debounce timeout. The debounce timeout
ensures that the jack detection status doesn’t change
unless the new state is persistent for longer than the time-
out. This prevents rapid changes on LSNS and JKSNS
during jack insertion/removal transients, and ensures
that false jack detection interrupts are not generated. The
debounce timeout can be programmed to one of four set-
tings from 25ms to 200ms (Table 77).
Ultra-Low Power Stereo Audio Codec
JKSNS
JACK DETECTION RESULTS
1
1
0
0
Headphones detected
Not possible/reserved
Headset detected
No jack detected
STATE
Maxim Integrated │ 144
JACKSNS
is