TS3A227E Datasheet, PDF (19/59 Pages) Texas Instruments – Autonomous Audio Accessory Detection and Configuration Switch

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TS3A227E
SCDS358B – NOVEMBER 2014 – REVISED FEBRUARY 2015
9.3 Feature Description
9.3.1 Accessory Configuration Detection
There are currently two difference configurations for headsets with microphones as shown in Table 1. Many
codecs requires that the system designer make a tough decision via a hardware connection which headset they
would like to support. This is done by directly connecting the microphone bias and the ground connections to the
sleeve and ring2 pins of the audio jack. For the end user this leaves a headset standard as fully unsupported.
Table 1. Two Difference Configurations for Headsets
PHYSICAL CONNECTOR
Tip
Ring
Sleeve
INTERNAL IMPEDANCE NETWORK
LR
G
PIN NAME CONFIGURATION
Tip
Audio Left
Ring
Audio Right
3-pole TRS
Tip
Ring1 Ring2 Sleeve
4-pole TRRS
16-2 kΩ
TRS
16-2 kΩ
600-4kΩ
LR
G
M
16-2 kΩ
Standard
16-2 kΩ
600-4kΩ
LR
M
G
Sleeve
Tip
Ring1
Ring2
Ground
Audio Left
Audio Right
Ground
Sleeve
Microphone
Tip
Ring1
Ring2
Audio Left
Audio Right
Microphone
16-2 kΩ
OMTP
Sleeve
Ground
16-2 kΩ
The TS3A227E fills this system gap by detecting the presence and location of the microphone and automatically
routing the MICBIAS and ground lines to support each headset. This enhances the overall user experience by
allowing headsets from all manufacturers.
9.3.2 Optional Manual I²C Control
The TS3227E also features optional manual I²C control for enhanced system flexibility. This allows the system
designer to manually control the switches and de-bounce settings at their discretion enabling the TS3A227E to
adapt to unique use cases.
This is an optional feature that does not need to be used for the device to operate autonomously.
9.3.3 Adjustable De-bounce Timings
The TS3A227E features manual control of the insertion de-bounce timer with selectable values. The default
insertion de-bounce timer is 90 ms.
This eliminates the need for external RC components which reduces BOM cost, the PCB footprint of the external
RC components. Further information on how to select an appropriate de-bounce timer can be found in the
application and implementation section.
Copyright © 2014–2015, Texas Instruments Incorporated
Product Folder Links: TS3A227E
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