LC75804E 查看數據表（PDF） - SANYO -> Panasonic

零件编号

产品描述 (功能)

比赛名单

LC75804E

1/3, 1/4 Duty LCD Display Drivers with Key Input Function

SANYO -> Panasonic 

LC75804E, LC75804W

3. In sleep mode

• The pins KS1 to KS6 are set to high or low by the S0 and S1 bits in the control data. (See the control data

description for details.)

• If a key on one of the lines corresponding to a KS1 to KS6 pin which is set high is pressed, the oscillator on the

OSC pin is started and a key scan is performed. Keys are scanned until all keys are released. Multiple key presses

are recognized by determining whether multiple key data bits are set.

• If a key is pressed for longer than 615T(s)(Where T= —fo1—sc ) the LC75804E/W outputs a key data read request (a

low level on DO) to the controller. The controller acknowledges this request and reads the key data. However, if

CE is high during a serial data transfer, DO will be set high.

• After the controller reads the key data, the key data read request is cleared (DO is set high) and the LC75804E/W

performs another key scan. However, this dose not clear sleep mode. Also note that DO, being an open-drain

output, requires a pull-up resistor (between 1 and 10 kΩ).

• Sleep mode key scan example

Example: S0 = 0, S1 = 1 (sleep with only KS6 high)

[L] KS1

[L] KS2

[L] KS3

[L] KS4

[L] KS5

[H] KS6

*4

KI1

KI2

KI3

KI4

KI5

When any one of these keys is pressed,

the oscillator on the OSC pin is started

and the keys are scanned.

Note: *4. These diodes are required to reliable recognize multiple key presses on the KS6 line when sleep mode state with only KS6 high, as in the above

example. That is, these diodes prevent incorrect operations due to sneak currents in the KS6 key scan output signal when keys on the KS1 to KS5

lines are pressed at the same time.

Key input

(KS6 line)

Key scan

CE

DI

615T[s]

615T[s]

Serial data transfer Serial data transfer Key address (43H) Serial data transfer

Key address

T=

1

fosc

DO

Key data read request

Key data read

Key data read

Key data read request

Multiple Key Presses

Although the LC75804E/W is capable of key scanning without inserting diodes for dual key presses, triple key presses on

the KI1 to KI5 input pin lines, or multiple key presses on the KS1 to KS6 output pin lines, multiple presses other than

these cases may result in keys that were not pressed recognized as having been pressed. Therefore, a diode must be

inserted in series with each key. Applications that do not recognize multiple key presses of three or more keys should

check the key data for three or more 1 bits and ignore such data.

No. 6266-18/37

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