User Guide

CC Technical Documentation System Module
NPM-10 (3595)
Issue 2 03/2004 ©2004 Nokia Corporation Confidential Page 33
PPH-1 Detection
PPH-1 accessory uses a four-wire fully differential audio connection. The accessory is
detected by the Headint signal when the plug is inserted. PPH-1 has two operating
modes with internal and external microphone. These modes can be separated by reading
the EAD value. Detection of the PPH-1 can be split into three main phases:
1. Micbias is set to high impedance state
2. HeadInt interrupt is detected
3. EAD reading is 2.0 V - 2.7 V -> PPH-1 connected
The PPH-1 has a function of speaker mute. It can be muted by setting micbias in low
state.
DC-OUT Interface
A special type of electrically A-cover called "DC-Out cover" is supported by the phone via
an electrical/mechanical interface connection. The kind of circuit that has to be powered
can be anything from simple LEDs to a "smarter" type of circuit.
Table 27: PPH-1 Identification
Name Function Min Typ Max Unit Description
HeadInt Accessory detection 2.2 2.78 2.86 V Accessory connected
Ead / HookInt Micbias = High-Z 2.064 2.182 2.302 V PPH-1 external mic
2.487 2.603 2.720 V PPH-1 internal mic
1.840 V PPH-1 speaker mute