ad1988a Analog Devices, Inc., ad1988a Datasheet - Page 18

• Manufacturer Part Number: ad1988a
• Description: High Definition Audio Soundmax Codec
• Manufacturer: Analog Devices, Inc.

AD1988A/AD1988B
JACK PRESENCE DETECTION
HD AUDIO STYLE JACK PRESENCE DETECTION
The AD1988 uses two jack sense pins for presence detection on
up to eight audio jacks. This, combined with the device identifi-
cation engine, enables software to determine if there is a device
plugged into the circuit, and the type of device it is. Allowing
software to configure jacks and amplifiers, as necessary, ensures
proper audio operation.
Table 16. Jack Sense Mapping
Resistor Value
(1% Tolerance)
2.67 kΩ
5.10 kΩ
10.0 kΩ
20.0 kΩ
39.2 kΩ
Name
Pull-up to AV
FRONT
LINE IN
FRONT_MIC
HP_OUT
DD
SENSE_A
Port
D
C
B
A
Rev. 0 | Page 18 of 20
Node ID
0x12
0x15
0x14
0x11
Detect jack presence by using a resistor tree arrangement
detailed by the HD audio specification, allowing up to four
jacks per sense line. Jacks must have normally open, isolated
switches to use this method of jack presence detection.
For proper operation, there must be a 2.67 kΩ 1% resistor
connected between SENSE_A and AV
1% resistor between SENSE_B and AV
The specific resistor values for each jack are listed in Table 16.
Use 1% tolerance resistors to ensure accurate detection.
Name
Pull-up to AV
SURR_SIDE (7.1)
C/LFE
SURR_BACK (5.1)
REAR_MIC
DD
SENSE_B
Port
H
G
F
E
DD
DD
, and another 2.67 kΩ
.
Node ID
0x25
0x24
0x16
0x17