Nokia 3110 COMPACT HANDSFREE UNIT

Programmes After Market Services

COMPACT HANDSFREE

UNIT PHF–3

issue 2 11/97

Compact Handsfree Unit PHF–3

After Sales

NHE–8/9

Technical Documentation

COMPACT HANDFREE UNIT PHF–3
Contents

Introduction NO TAG
General NO TAG
Technical Summary NO TAG
Operation NO TAG
List of Modules NO TAG
Basic Specifications NO TAG
Modes of Operation NO TAG
External Signals and Connections NO TAG
Circuit Description NO TAG
Block Diagram NO TAG

Audio Interface Page 7

Power Supply Page 7

Microphone Amplifier Page 7
Xear Amplifier Page 7
Volume Control and Mute Page 7
Speaker Amplifiers Page 7

Charger Page 8

Control Circuit (MCU) Page 8

External I/O and AD–converters Page 8

Connectors Page 8

Input Protection Page 8
Circuit Diagram of DC9 NO TAG
Circuit Diagram of DC9 NO TAG
Layout Diagram of DC9 (version 07) NO TAG
Parts List of DC9 (EDMS Issue 8.2) NO TAG
Exploded View of PHF–3 NO TAG
Assembly Parts NO TAG

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issue 2 11/97

After Sales

Compact Handsfree Unit PHF–3

Technical Documentation

Introduction

General

The PHF–3 is a handsfree unit for handportable (NHE–6 and NHK–6) phones. It
provides rapid charging for the phone and a possibility to use HF–operation. The
PHF–3 cannot be connected directly to the phone but via the external antenna unit
AAH–1D and mobile holder MBT–5 or other devices that provide the HF connector .

Technical Summary

Operation

The PHF–3 has external connections to car battery, ignition sense, car radio
muting, external microphone and external speaker. The unit has a HF–connector
that provides an interface to the phone via external antenna unit. The connection
can be made directly or using the extension cable between PHF–3 and AAH–1D.
There is also an internal speaker inside the handsfree unit.

The unit consists of a switching mode rapid charger, HF–speaker and
HF–microphone amplifiers, volume control circuit, voltage regulators, control
circuit (microprocessor) and a CAP compatible interface.

NHE–8/9

The PHF–3 is always connected to the car battery . To save the car battery , PHF–3
goes in to the sleep mode if the car is not running and/or the phone is not
connected.

List of Modules

Name of Module: Material Code:

HF speaker module DC9 0200656
Assembly parts MPHF–3 0260681

Basic Specifications

Function: Value:

Input voltage 11.3 ... 16 V
Current consumption 2 A dc max
Power source car battery

Page 3

Compact Handsfree Unit PHF–3

After Sales

NHE–8/9

Modes of Operation

Phone not connected (sleep mode):

When the phone is not connected the current consumption of the device has been
minimized. The switching mode power supply (SMPS) and audio circuits has been
turned off. PHF–3 is only waiting a phone to be connected.

Phone connected (active mode):

When the phone is connected to the PHF–3 it goes into the active mode. In the
active mode the device provides charging current to the phone via SMPS. It also
can provide hands free call option using the internal or the external speaker (if
connected) and the external microphone. If more private call wants to be made, the
phone itself can be used as a handset without losing the external antenna
connection.

The phone controls all the basic functions of PHF–3 that are required for making
calls. In the active mode the PHF–3 follows the commands received from the phone
via mbus.

PHF–3 also provides car radio mute function during call. This is possible only in
those radios which support that function.

Technical Documentation

PHF–3 can control the mobile antenna motor if it is installed to the car.

External Signals and Connections

D.C. Supply Connector X100

Pin: Signal name: Function:

1, 2 +VB Input from car battery

3 IGNS Ignition sense low

4 CRM Car radio mute off

5 AMC Antenna motor control off

• min/max voltage: 8.0...13.5...16 V dc

• max 1.8 V

Ignition sense high

• min/nom/max 8...13.5...32 V

• nom 0 mA / open collector output

• max 16 V

Car radio mute on

• nom 150 mA / current limiting value

• nom/max 12...15.5 V / at max. current

• nom 0 mA / open collector output

Car radio mute on

• nom 150 mA / current limiting value

• nom/max 12...15.5 V / at max. current

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6,7,8 GND Ground

issue 2 11/97

After Sales

Compact Handsfree Unit PHF–3

Technical Documentation

System Connector X400

Pin Signal name: Function:

1 GND Digital ground
2 XMIC Microphone signal

3 MBUS MBUS line low

4 SGND Signal ground
5 XEAR Speaker signal

6 IGNS Ignition sense

NHE–8/9

• nominal voltage: 60 mVrms

• min/max voltage: 0...0.5 V

MBUS line high

• min/max voltage: 2.4...3.2 V

• typ voltage: 60 mV

• typ voltage: 13.5 V

Pin Signal name: Function:

7,8 +VC Supply voltage
unloaded
limit

9...12 GND Ground

External Microphone Connector X200

Pin: Signal name: Function:

1 GND Ground
2 HFMIC Microphone signal typ voltage: 0 V

External Speaker Connector X300

Pin: Signal name: Notes:

• typ/max voltage: 10.3...10.8 V /

• typ/max current: 780...832 mA / current

Microphone bias typ voltage: 2.5 V dc

1 Speaker – 8 Ω speaker, 3.2 mm jack
2 Speaker +

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Compact Handsfree Unit PHF–3

After Sales

NHE–8/9

Circuit Description

The circuit blocks are described in the following subsections. Refer to block
diagram in next section. The complexity for each block is given. Note that every
operational amplifier are calculated as a component whereas there actually might
be several amplifiers in one physical (IC) component.

CHARGE
SMPS

CHGON

EXTERNAL
I / O

CRM

AMC

CRM
AMC
IGNS

IGNS

Technical Documentation

VCC

DC connector
X100

VCC

RESET

XEAR

VCHG

System connector
X400

SGND

CAP AUDIO
INTERFACE

MIC

MICROPHONE
AMPLIFIER

CONTROL

MBUS

XMIC

HFEAR EAR

VOL

VOLUME
CONTROL
Attenuation
0 – 28 dB

CIRCUITS

MUTE

ON / OFF

+3V3

PWRON

PRE–
AMPLIFIER

EAR +5V

POWER
AMPLIFIER

SPKR+

POWER
SUPPLY

+5V

V AMP

SPKR–

Page 6

HFMIC

External Microphone
Connector X200

Internal Speaker
Connector X301

External Speaker
Connector X300

issue 2 11/97