UPD16682AP datasheet(39/58 Pages) RENESAS

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Data Sheet S14402EJ1V0DS

µµµµPD16682A

Figure 12–5. Power Save

Static indicator OFF

Static indicator ON

Power save (compound command)

Sleep mode

Static indicator ON

Reset command

Standby mode

Power save OFF

(Display all OFF command)

Cancel sleep mode

Cancel standby mode

Power save OFF

(Display all OFF command)

12.20.1 Sleep mode

During this mode, all LCD operations are stopped and there is no access from the CPU, so current consumption

can be reduced almost as low as the static current level. The internal status during sleep mode is as follows.

(1) The oscillation circuit and LCD power supply circuit are stopped.

(2) All LCD drive circuits are stopped and both segment and common driver outputs output at the VSS level.

12.20.2 Standby mode

During this mode, all duty LCD display system operations are stopped and only the static drive system for the

indicators operate, which reduces the current consumption to the minimum amount needed for static drive. The

internal status during standby mode is as follows.

(1) The LCD’s power supply circuit is stopped. The oscillation circuit operates.

(2) The duty drive system’s LCD drive circuit is stopped and both segment and common driver outputs output at

the VSS level. The static drive system operates.

When a reset command is executed while in standby mode, it sets sleep mode.

Remarks1. If you are using an external power supply, we recommend that you stop the external power supply

circuit’s functions when activating the power save function. For example, if you are using an external

divided resistor circuit to provide LCD drive voltage at different levels, we recommend that you add a

circuit to cut the current flowing on the divided resistor circuit while the power save function is being

activated.

2. The

µ PD16682A includes the /DOF pin which is used to control blinking LCD displays is set to low

level when activating the power save function. The output from /DOF can be used to stop the external

power supply circuit's function.

3. When the display has been set to OFF mode, executing the display all ON command sets power save

mode no matter which command is entered afterward.

UPD16682AP датащи(PDF) 39 Page - Renesas Technology Corp