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SAMSUNG Proprietary-Contents may change without notice
Circuit Description
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2-3
2-2. Baseband Circuit description of SGH-Z140
2-2-1. PM6650
- 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 seven LDO support for 1.375V, 1.8V, 2.6V, 2.85V, 3.0V, 3.3V
while a self-resetting, electronically fused switch supplies power to external accessories. Ancillary support functions,
such as RTC module and RTC charger, Clock Buffer, aid in reducing both board area and system complexity.
SBI BUS serial interface provides access to control and configuration registers. This interface gives
full control of
the MSM6250 and enables system designers to maximize both standby and talk times.
Supervisory functions. including a reset generator, an input voltage monitor, and a ADC Conertte support reliable
system design. These functions work together to ensure proper system behavior during start-up or in the event of a
fault condition(low microprocessor voltage, insufficient battery energy, or excessive die temperature).
- TCXO Controller and Buffers
The PM6650 IC includes circuits for controlling the TCXO warm-up and buffering its signal for distribution
throughout the handset. Performance specifications are presented below.
2-2-2. Connector
- LCD Connector
LCD is consisted of main LCD(color 260K TFT LCD) and small LCD(color 65K LCD). Main LCD has 1.8", 176x220
resolution and sub LCD has 1.07", 96x96 resolution. Sub LCD uses STR to improve reflection performance. Chip
select signals in MSM6250, MLCD_CS_N can enable main LCD and SLCD_CS_N can enable small LCD.
MLCD_BL_EN enables white LED of main LCD. MLCD_RESET signal initiates the reset
process of the main LCD. SLCD_RESET signal initiates the Reset process of the small LCD.
- Key
This is consisted of key interface pins among U301, KEY_N(0:4). These signals compose the matrix. Result of
matrix informs the key status to key interface in the U301. Power on/off key is seperated from the matrix. The key
LED use the "VREG_KEY_LED" supply voltage. "HALL_SW" informs the status of folder (open or closed) to the.
- EMI ESD Filter
This system uses the EMI ESD filter, GMF05LC to protect noise from IF CONNECTOR part.
- IF connetor
It is 24-pin connector. They are designed to use VBATT, VF, MSM_TDI, MSM_TDO, MSM_TCK, MSM_TMS,
MSM_TRST, MSM_RTCK, RFR, CTS, JIG_ON, USB_VBUS, RXD, TXD, BOOT_SW and GND. They connected to
power supply IC, microprocessor and signal processor IC.