Reset Circuit - Panasonic EB-G450 Technical Manual

ACCESSORIES

U310 and U314 form the reset circuit. U314 is a voltage level detector whose output goes low if the supply drops

below 4.5V. When nHF ON is low (P201 pin 7), Q307 is switched on, pulling the input to U310 high. This signal

also feeds the two analogue switches turning them on. On this line going high U310 Q output will go high for a

predefined time of approximately 5uS, turning Q308 ON and pulling the reset line low.

10.1.3 Path Description

The following lists the direct connection between parts of a given portion of the circuit.

TX Audio

Path from P301 Pin 1 Microphone connection on PCB-GND REF POINT TP309

P301

2 PIN Connector

U311

Amplifier

U305

CODEC

U306

DSP

U304

CODEC

U301

Amplifier

U312

Analogue Switch

U315

Amplifier

P201

16 PIN Connector

RX Audio

Path from P201 Pin 4 (RX_Audio) Main unit connector on PCB-GND REF POINT TP312

P201

16 PIN Connector

U301

Amplifier

R324

Volume Control

U304

CODEC

U306

DSP

U305

CODEC

U313

Analogue Switch

U308

Output Amplifier

J300

Ext Speaker Socket

P300

2 PIN Connector

Issue 1

Revision 0

http://cxema.ru

Pin 1 or TP310

Input pin 1

Input pin 24

Input pin 9

Input pin 12

Input pin 5

Input pin 2

Input pin 3

Pin 3 (TX_Audio) or TP201

Pin 4 (RX_Audio) or TP304

Input pin 2

Input pin 1

Input pin 24

Input pin 10

Input pin 12

Input pin 1

Input pin 1

Input pin 2 or TP311

Pin 2

Section 10

10 - 2

Output pin 4

Output pin 13

Output pin 13

Output pin 5

Output pin 7

Output pin 1

Output pin 4

Output pin 1

Output pin 2

Output pin 13

Output pin 14

Output pin 5

Output pin 2

Output pin 4

Output pin 3

MCUK971001G8

Technical Guide