3. TECHNICAL BRIEF
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 |
| 2V62_VIO | SDA |
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| C400 |
| KEY I2C_ |
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| 0.1uF |
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2V62_VIO |
| R400 | 0 |
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| 120K |
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C401 | 0.1uF | (1%) |
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| R401 |
2V62_VIO
R402 | 4.7K |
KEY_COL7 KEY_COL6 KEY_COL5
KEY_INT KEY_I2C_SCL
2V62_VIO
27p | 27p | 27p |
C402 | C403 | C404 |
R405 470
R407 470
R409 470
R411
R413
R415
4.7K
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| 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | ||
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| 1 | PGND GND2 | RESETB | XI | XO | CLK SEL | VDD | P10 | |||
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| 2 | TEST |
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| SEL_28P |
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| 3 |
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| P57 |
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| 4 |
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| U400 |
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| 5 | P56 |
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| PP2106M2 |
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| P55 |
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| 0 |
| 6 |
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| P17 |
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| 7 |
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| P15 | GND1 | P54 | P53 | P52 | P51 | P50 | P47 | ||
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| 8 | 9 | 10 | 11 | 12 | 13 | 14 | ||
P40 | 21 |
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| R403 | 470 | KEY_ROW0 |
20 |
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| R404 | 470 | ||
P41 | 19 |
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| R406 | 470 | KEY_ROW1 |
P42 | 18 |
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| R408 | 470 | KEY_ROW2 |
P43 | 17 |
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| R410 | 470 | KEY_ROW3 |
P44 | 16 |
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| R412 | 470 | KEY_ROW4 |
P45 | 15 |
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| R414 | 470 | KEY_ROW5 |
P46 |
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| KEY_ROW6 |
| C413 | C414 | C415 | C416 | C417 | C418 | C419 |
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| 27p | 27p | 27p | 27p | 27p | 27p | 27p |
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C420 27p
C421 27p
C422 27p
C423 27p
C424 27p
470 | 470 | 470 | 470 | 470 |
R416 | R417 | R418 | R419 | R420 |
| KEY COL4 | KEY COL3 | KEY COL2 | KEY COL1 KEY COL0 |
Figure 11-1. Keypad Configuration Circuit
Copyright © 2008 LG Electronics. Inc. All right reserved. | - 39 - | LGE Internal Use Only |
Only for training and service purposes |
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