User Guide

PAMS
Technical Documentation
NSE–8/9
System Module
Page 2– 71
Issue 1 07/99
When the signal , BUZZER, is high, current runs through the buzzer, and
when it’s low no current flow. The BUZZ_CNT pin is has an internal
pull–down resistor.
UISWITCH has a low on–resistance FET switch for the buzzer (pin
BUZZER) and an internal protection diode.
Vibra, NSE–9 only
A vibra alerting device is used for giving silent signal to the user of an
incoming call. The device is controlled with by a PWM signal, VIBRA,
which is supplied by MAD2PR1. The vibra alert can be adjusted either by
changing the pulse width or by changing the pulse frequency. The vibra
device is inside the phone.
Each time the vibra is activated the sw commands the DC/DC converter
output to max level to have the highest voltage swing available for the
vibra.
When the signal , VIBRA, is high, current runs through the vibra, and
when it’s low no current flow. The VIBRA_CNT pin is has an internal
pull–down resistor.
The UISWITCH has a low on–resistance FET switch for the vibra (pin
VIBRA) and a internal protection diode.
LCD
The LCD module for NSE–8/9 consists of a 84 by 48 dot matrix display
with a driver chip on the display glass. The driver has an internal free
running clock oscillator used for the logic inside the driver as well as for
the display frame frequency. The oscillator frequency is 16.3 KHz and the
frame frequency is 80 Hz.
The display driver has an internal voltage tripler circuitry for generation of
a negative supply rail required for operation of the liquid crystal material.
Capacitor C401 is used by this voltage booster.
R420 and R421 are used for improved ESD protection, thus preventing
the display from resetting, when ESD is applied to the display frame etc.
The display is connected to the system board via a Zebra connector X400.
Besides the supply voltage, Vbb, GND and external capacitor connection,
C401, the interface consists of a 5 wire write only serial interface:
– LCDRSTX reset signal from MAD2PR1 (MCUGenIO2) which is protected
against un intended resets by R421 and R420, caused by ESD on the dis-
play frame.
– LCDEN chip enable from MAD2PR1 (LCDCSX)
– LCDCD Command/Data signal from MAD2PR1