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SAMSUNG Proprietary-Contents may change without notice
Circuit Description
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2-3
2-2. SGH-Z540 Baseband Circuit description
1. PM6650-2 (PAM200)
1.1. Power Management
Ten low-dropout regulators designed specifically for GSM applications power the terminal and help ensure optimal
system performance and long battery life. It provides LDOs support for 1.375V, 1.8V, 2.6V, 2.85V, 3.3V.
IC-level interfaces include the three-line serial bus interface(SBI) used by the MSM6250 device to control
and status the PM6650-2 IC.
1.2. Keypad Backlight
The Keypad backlight driver output is at pin 23 (KEY_EL_DRV) and is designed to drive EL on KEY FPCB. Its
output current level is SBI-programmable and meets the performance specified below.
Input parameters are not specified since they are internal.
1.3. TCXO Controller and Buffers
The PM6650-2 IC includes circuits for controlling the TCXO warm-up and buffering its signal for distribution
throughout the handset. Performance specifications are presented below.
2. Connector
2-1. LCD Connector
LCD is consisted of main LCD(color 262K TFT LCD) and small LCD(color 65K TFT LCD). Chip select signals in
the HDC400, MAIN_LCD_CS can enable main LCD and SUB_EL_CS can enable small LCD. nRESET_LCD
signal initiates the reset process of the main LCD and sub LCD. 16-bit data lines(D2(0)~D(15)) transfers data and
commands to LCD.
Power signals for LCD are "VBATT_LCD". "EAR1O_P,N" and "SPK_R,K" from UCP100 are used for audio
speaker. And "VCC_MOTOR_3.3V" from U402 enables the motor.
2-2. Key
This is consisted of key interface pins among UCP100, KEYSENSE_N(0:3). These signals compose the matrix.
Result of matrix informs the key status to key interface in the UCP100. Power on/off key is seperated from the
matrix. The EL key PAD use the "VREG_MSMP_2.6V" voltage.
"HALL_SW" informs the status of folder (open or
closed) to the. This uses the hall effect IC, EM-1681-FT
2-3. EMI ESD Filter
This system uses the EMI ESD filter, ECLAMP2378P to protect noise from IF CONNECTOR part.