User Guide

PAMS
Technical Documentation
RAE-5
4. User Interfaces
Page 4 – 16
Issue 1 04/02
The frame includes clips to mechanically attach the display to the UL2 PWB
and also keep LCD cell and lightguide in place.
LCD cell specification
The LCD cell includes the display driver.
PDA LCD Module .
PDA LCD circuit main blocks are LCD glass including drivers, PDA LCD bias
voltage power circuit and a control IC.
Parameter Function
Display resolution 640 (x3) x 200 dots
Active area 107.52 x 33.6
Dot pitch 0.168 x 0.168mm
Display mode D–TFD, Color, Transmissive
Frame frequency 51.5 Hz typical
Colors 4096 colors, 12–bit RGB
Display brightness 100nit (full brightness typical)
PDA LCD Backlight circuit
Figure 3. Backlight Power Supply
Control
circuit
Driver
Piezo
transformer
CCFL
VB
VBB
BACKPWM
DISPON
The control circuit generates a square wave input to the piezo driver circuit.
This signal is maintained at the resonant frequency of the piezo transformer.
The driver is based around 2 FETs in Push–pull configuration. There is a single
coil between the FETs and the piezo transformer.
Both FETs are turned off while the CCFL is off during dimming (BACKPWM
low).