Keypad Switching & Scanning; Only For Training And Service Purposes - LG KS360 Service Manual

3.9 Keypad Switching & Scanning
The keypad is controlled by a Key coder IC (PP2106M2). It can be used for scanning keypads up to 8
rows and 8 columns (max 64 keys). PMB8888 control PP2106M2 by KEY_I2C_SCL, KEY_I2C_SDA
and KEY_INT.
QWERTY KEY
R405
KEY_COL7
R407
KEY_COL6
R409
KEY_COL5
KEY_INT
KEY_I2C_SCL
Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes

C400
0.1uF
2V62_VIO
C401 0.1uF
1
TEST
2
SEL_28P
470 3
P57
470 4
P56
470 5
P55
R411 0 6
P17
R413 0 7
P15
R415
4.7K
C420 27p
C421 27p
C422 27p
C423 27p
C424 27p
Figure 11-1. Keypad Configuration Circuit
3. TECHNICAL BRIEF
2V62_VIO
2V62_VIO
R400
120K
(1%)
21
P40
20
P41
19
P42
U400 18
P43
PP2106M2 17
P44
16
P45
15
P46
- 39 -
R403 470
KEY_ROW0
R404 470
KEY_ROW1
R406 470
KEY_ROW2
R408 470
KEY_ROW3
R410 470
KEY_ROW4
R412 470
KEY_ROW5
R414 470
KEY_ROW6
LGE Internal Use Only