User Guide

PAMS
Technical Documentation
NSE–8/9
System Module
Page 2– 68
Issue 1 07/99
Audio accessory detection
When a jack is plugged into the bottom connector X503 it activates the
bottom connector switch, thus opens the connection between R200 and
R202 which will make HEADDET pin on MAD go high indicating an
interrupt to the SW. When no accessory is present the switch inside the
bottom connector X503 is closed and HEADDET is pulled low by R202.
When SW has acknowledged the interrupt it starts a sequence of
commanding the AUXOUT voltage of the Cobba to different levels while
reading the voltage at EAD (by way of the EAD ADC in CCONT. When the
PPH–1 unit is connected the sw even stops the charger current from
flowing in order not to make it offset the level measured during the
identification, due to charge gnd. being the only common dc reference.
For a full description of the audio accessory detection including detection
levels.