SAMSUNG Proprietary-Contents may change without notice
Circuit Description
2-3
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3. Backlight LED Driver
The backlight LED driver is a low-side, programmable current source designed to control the brightness of the keyboard
illumination.
LED1_DRV is controlled via LED1_[0:2] and can be programmed to sink from 15mA to 60mA in 7.5mA
steps. LED2_DRV is controlled via LED2_[0:2] and can be programmed to sink from 5mA to 40mA in 5mA steps.
Both LED drivers are capable of sinking their maximum output current at a worst-case maximum output voltage of 0.6V.
For efficient use, the LEDs is connected between the battery and the LED_DRV output.
4. Vibrator Motor Driver
The vibrator motor driver is a independent voltage regulator to drive a small dc motor that silently alerts the user of an
incoming call. The driver is a 3.3V constant source while sinking up to 140mA and controlled by enable signal of main
chip. For efficient use and safety, the vibrator motor should be connected between the regulator output and the ground.
2) Connector
1. LCD Connector
LCD is consisted of main LCD(color 65K STN LCD). Chip select signals of EMI part in the trident, LCD_CS, can
enable main LCD. LED+ signal enables white LED of main LCD. In sleep mode, white LED are turned off.
These two signals are from IO part of the DSP in the trident. RST signal from CSP2200B1 initiates the initial process of
the LCD.
8-bit data lines(D(0)~D(7)) transfers data and commands to LCD through emi_filter. Data and commands use A(2) signal.
If this signal is high, Inputs to LCD are commands. If it is low, Inputs to LCD are data.
The signals which inform the input or output state to LCD, are required. But this system is not necessary for read enable
signal. CP_WEN signal is only used to write data or commands to LCD.
Power signal for operating LCD driver is VCCD.
2. JTAG Connector
Trident has two JTAG ports which are for ARM core and DSP core(DSP16000). So this system has two port connector
for these ports. Pins' initials for ARM core are 'CP_' and pins' initials for DSP core are 'DSP_'.
CP_TDI and DSP_TDI signal are used for input of data. CP_TDO and DSP_TDO signals are used for the output of the
data. CP_TCK and DSP_TCK signals are used for clock because JTAG communication is a synchronous. CP_TMS and
DSP_TMS signals are test mode signals. The difference between these is the RESET_INT signal which is for ARM core
RESET.