Dtc Key Part - Circuit Diagram - Philips MX5800SA Service Manual

VOLUME FTD DISPLAY PIN CONFIGURATION
BLOCK DIAGRAM
VDD
VSS
/CS
/RD
/WR
LCD CONTROLLER/
DATA 1
DRIVER
'HOLTEK'
HT1621
(Die form)
BZ1
BZ2
LED+
LED-
PIN CONFIGURATION
Pin No. Symbol. Description
1 VDD Power supply for logic circuit (+5V)
2 VSS Power supply negative, ground (0V)
3 /CS Chip selection input with pull-high resistor.
When the CS is logic high, the data and command read from or written to the
HT1621 are disabled. The serial interface circuit is also reset. But if CS is
at logic low level and is input to the CS pad, the data and command
transmission between the host controller and the HT1621 are all enabled.
4 /RD READ clock input with pull-high resistor.
Data in the RAM of the HT1621 are clocked out on the falling edge of the RD
signal. The clocked out data will appear on the DATA line. The host controller
can use the next rising edge to latch the clocked out data.
5 /WR WRITE clock input with pull-high resistor.
Data on the DATA line are latched into the HT1621 on the rising edge of the
WR signal.
6 DATA Serial data input/output with pull-high resistor
7 LED+ Anode of backlight
8 LED- Cathode of backlight
9 BZ1 Bezel ground (connected together)
10 BZ2 Bezel ground (connected together)
6-2
LCD Segment Display
WHITE LED BACKLIGHT

DTC KEY PART - CIRCUIT DIAGRAM

1400 A1 1402 B3 1404 A4 2400 B4
1401 A2 1403 B3 1405 B4 3400 A2
1 2
1400
A
1 GND_B
DISC1
2
EH-S
B
GND_B
1 2
6-2
3401 A3 3403 A4
3402 A3
3 4
DISC2 DISC3 DISC4
DISC5
3400 3401 3402 3403
150R 220R 270R 390R
GND_B GND_B GND_B GND_B
GND_B
8239 210 9413 pt4 dd wk0323
3 4
A
B