Display Backlight is made by 4 LEDs connected in parallel (in bottom of the Display).
Keyboard Backlight is made by 4 LEDs connected in parallel. Color of all LEDs is yellow-green, l = 570nm
Switching circuits for Display and keyboard backlight is controlled by the same signal: KBLIGHTS.
KBLIGHT-signal = HIGH -> the lights are on KBLIGHT-signal = LOW -> the lights are off. UISWITCH is used for controlling backlight. Ul-Switch
Detailed description ofthe UISWITCH isgiven in document/16/.
The UISWITCH is an integrated switch IC for UI (user interface) purposes. It includes control switch for buzzer and vibra, LED-control (display ft keyboard) and two current sinks for LED's.
- 2 adjustable constant current sink (60mA each) for keyboard and LCD-LEDs
- LED ON/OFF control (separated for keyboard and LCD)
- BuzzerON/OFF control
- FET switch (low Rds-on) for buzzer current
- Vibra ON/OFF control
- FET switch for vibra current
- Thermal shutdown
- Power down function for optimum current consumption
- Package TSSOP20 because of 1.5mm height requirement
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You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.