Nokia 252 System Module Schematics

Programmes After Market Services

NHA–3 Series Transceivers

Chapter 3

System Module

Issue 2 06/98

NHA–3
System Module

Technical Documentation

CONTENTS

Introduction 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Technical Specifications 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Modes of Operation 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

External signals and connections. 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

internal Signals 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Functional Description 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Baseband Circuit Description 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General 3 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

AMSA System Asic D400 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

AMSA D400 signals 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Microcontroller D300 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microcontroller D300 signals 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

EEPROM D301 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Regulation 3–1 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAOS2 asic N200 and charging control 3–11. . . . . . . . . . . . . . . . . . . . . .

RF Circuit Description 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receiver 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rx Synthesizer 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rx loop filter 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rx VCO 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tx synthesizer 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TX VCO 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tx loop filter 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmitter 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

AFC function 3–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parts List 3–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Amps System Module Authenticated 3–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Namps System Module Authenticated 3–25. . . . . . . . . . . . . . . . . . . . . . . . . . . .

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List of Figures

PCB Version 10.1

Figure 1. Baseband Block Diagram 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2. Rf Block Diagram 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 3 System Block Diagram 3–A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 4 Baseband Block Diagram 3–A2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 5 Asic Circuit Diagram 3–A3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 6 CTRLU Circuit Diagram 3–A4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 7 PSU Circuit Diagram 3–A5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 8 RF Block Diagram 3–A6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 9 RX Circuit Diagram 3–A7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 10 TX Circuit Diagram 3–A8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page No

Figure 11 Component Layouts 3–A9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Note: In printed manuals all A3 drawings are located at the back of the binder

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Introduction

The H700 system module controls the operation of the transceiver.

These tasks include UI module control (keyboard, LCD, transducers,

accessory control), and all system signalling, audio processing , and RF

functions.

Technical Specifications

Modes of Operation

The module has 4 basic modes:

– Charging only: The phone is off, the only functions are battery charg-

ing
– Local mode: The phone is under external control via MBUS.
– Standby mode: the phone is ready to receive and make calls.
– Conversation mode: the phone is in a call, all RX and TX paths are ac-

tive.

System Module

External signals and connections.

The module has 2 connections:

– Board to board connector:

X200 44 way connector to the UI module.

– RF antenna connection:

X201 GND clip, X202 ANT clip.

The connectivity, functionality and performance of the board to board
connector is described in the UI module description. The pin numbering is
identical in the UI module and system module.

The performance of the antenna connection is described in the
Performance section

internal Signals

Table 3. Baseband / RF interface signals

Control signal Description

VBATT Battery supply voltage

GND Battery ground connection

PAC Filtered PWM power control signal for the transmitter

PAEN Power amplifier enable

VTX Regulated dc voltage for the low power transmitter stages

TXI Indicates when RF is present at the output of the transmitter

RXENX Enables the LNA, IF buffer ,FMIF and AFC buffer

VRX Regulated dc voltage for the receiver

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Table 3. Baseband / RF interface signals (continued)

DescriptionControl signal

FSEL Selects AMPS/NAMPS 2nd IF filtering

RSSI Received signal strength indication

RXAF Received audio and data

IF2 2nd IF providing input to the AFC loop

LNABOOST Linearises the LNA in transmit mode

SYNDATENX Serial data enable for the synthesiser

SYNDAT Serial data bus for programming the synthesiser
SYNCLK Serial data clk input for the synthesiser

SYNTHENX Enables UHF VCO/buffer and controls synthesiser power down.

AFCDAC Voltage used to control TCXO output frequency

LOCKDET Indicates when synthesisers are in lock

TXMOD Modulation signal containing AMPS/NAMPS modulation

Technical Documentation

PAMS

REFFREQ VCTCXO output used to provide baseband clock
NEGVCLK Required for synthesiser voltage doubler

Functional Description

Baseband Circuit Description

General

The audio/logic unit consists of 4 ICs: AMSA system asic D400, MCU
D300, EEPROM D301, and CHAOS2 charger switch asic N200. These
ICs together with the supporting discrete circuitry make up the Baseband
block.

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Baseband Block Diagram

RF

Figure 1. Baseband Block Diagram

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AMSA System Asic D400

AMSA is a 100pin TQFP mixed signal asic with the following functionality:

– Power–on / reset control, watchdog timer.
– Modem for AMPS/NAMPS
– Audio Processing for AMPS/NAMPS
– PLL and clock generation for BB system (using VTCXO as reference)
– I/O ports, allowing interrupt controlled MCU activity from keyboard and

accessories.

AMSA D400 signals

PAMS

Technical Documentation

pin

Power up / Reset /Clock generation signals

2 LowbattRstX Low battery reset input

3 OnRstX PLL–on reset delay input.
73 PwrKeyX Power key input for power on only
74 ChrgDet Charger detection input for power on only.
76 Regen VRX regulator and MCU enable.
20 MCUClk 4.8MHz MCU clock output
98 BBRstX MCU reset

4 NegVClk 320kHz clock for RF voltage doubler.

5 LCDClk 160kHz LCD clock output

92,93 PLLRC1,2 PLLRC filter connection for the 19.2Mhz AMSA PLL.

95 TCXO external 14.85MHz reference input for AMSA PLL

100 XIn Tied to GND, selects internal PLL.

AMSA / MCU interface

22 – 29 D7 – D0 Data bus
31 – 36 A0 – A5 AMSA Address bus

37 RdX AMSA read enable
38 WrX AMSA write enable
40 CS AMSA chip select
41 IntX MCU interrupt output

RF control signals

53 AFCDAC DAC output controlling VTCXO frequency
89 IF 450kHz 2nd IF counter input.
97 SYNTHENX Synth power enable (used for RX part in H700)
75 RXENX RX power enable (used for VCO supply enable in H700)
81 FMEN PLL PM modulation enable, for blocked channel elimination.
83 LNABOOST Open drain linearises the LNA in transmit mode
84 VTXEN VTX enable signal
85 FSEL AMPS/NAMPS filter selection
87 P AEN Transmit PA enable signal

label Function

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pin Functionlabel

UI / accessory control signals

7 (not used)

8 (not used)

9 ReqA Audio request accessory interrupt.
10 MBUS_AMSA MBUS detection produces an interupt
13 LCDRstX LCD reset signal

14 –18 Row (4:0) Keyboard Row0 to Row 4

Receive path signals

43 RxVMid DC bias for RX path. Decoupled to GND
77 RxGain Rx input amplifier feedback
78 RxIn Rx input amplifier input
49 HDSet Accessory external audio output (HEAR signal)
46 EARP Internal earpiece audio output

Transmit path signals

55 TxVMid DC bias for TX path. Decoupled to GND
58 XMic Accessory microphone audio input
59 BMic2 Internal microphone dc bias voltage.
60 BMic1 Headset dc bias / handsfree mute voltage.
61 CMic decoupling pin for BMiC
63 Mic2 Internal microphone audio input.
64 Mic1 Headset microphone audio input.

65, 68 MicGain 1 , 2 Mic amplifier gain feedback path
51, 69 STI,STO sidetone signal path

71 TxO Transmit modulation audio output to RF
82 BMicDis Discharge for BMic1 capacitor.

System Module

Microcontroller D300

This 80pin QFP MCU has the following features: internal ROM with code
protection, RAM, 8 channel 10bit A–D converter, Serial interface, and 6
configuarable I/0 ports.

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Microcontroller D300 signals

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Technical Documentation

pin

1 PAC TX power control

3 BuzzPWM Buzzer signal to UI PCB

7 ChrgMonPull ChrgMon adjustment (high Z in reset, logic 0 when MCU

9 TxD MBUS transmit serial data
10 RxD MBUS receive serial data

13 – 20 D0 – D7 AMSA data bus
22 – 27 A0 – A5 AMSA address bus

31 Col0 Keypad–Matrix Column 0

32 Col1 Keypad–Matrix Column 1

33 Col2 Keypad–Matrix Column 2
34 Col3 Keypad–Matrix Column 3

35, 36 Light0, Light1 Backlighting control

37 IntEarEn Internal earpiece driver enable
39 RdX AMSA read control line
40 WrX AMSA write control line
41 CS AMSA chip select
59 RFTEMP RF temperature monitor
60 RSSI Signal strength indication
61 TXI Transmit Indicator
62 BTemp Battery temperature
63 BSI Battery size indication
64 AccID Accessory ID A–D input connected to ReqA
65 ChrgMon Charger voltage monitor
66 BattMon Battery voltage monitor
70 IntX AMSA interrupt
72 LOCKDET Synth lock detect
73 SYNCLK Synth Control, clock
74 SYNDAT Synth Control, data
75 ChrgCrtl ELVI fast charger control (32Hz)
76 SYNDATENX Synth Control, enable
77 VIBRA Vibration alert enable (10kHz), multiplexed onto BTEMP
78 SDA I2C Bus, data,
79 ChrgSW Charger switch control for Chaos2
80 SCL I2C Bus, clock

label Function

running.)

LCDDC Serial LCD driver data or command.

LCDSDA Serial LCD driver data

LCDSDCLK Serial LCD driver data clock

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