S1M8656 Samsung Semiconductor, Inc., S1M8656 Datasheet - Page 16

• Manufacturer Part Number: S1M8656
• Description: RX if / Bba With Agc
• Manufacturer: Samsung Semiconductor, Inc.

S1M8656A
Rx Voltage Controlled Oscillator(VCO)
S1M8656A includes the Rx LO block having the VCO and quad-phase generator. The quad-phase generator
outputs I-phase and Q-phase clocks with 1/2 the VCO frequency and sends them to the QPSK modulator. The
VCO buffer is used when the VCO output is sent to the external RX PLL. Although the allowable VCO frequency
is determined based on an external time constant, it can only range between approx. 100MHz – 500MHz,
suggesting that the maximum input IF frequency is 250MHz.
Serial Port Interface(SPI)
S1M8656A is equipped with the Serial I/F. All internal functions can be controlled through a common bus using
an external controller. The serial I/F can be used by setting pin 26(SEN) high, the pin which permits/ not permit
the SPI. If the SEN becomes low, the SPI cannot be used and the BBA must be used in the existing BBA 2.0
mode. (All the internal registers are default, which makes the register have the same characteristic as BBA 2.0)
Here, the modem is the master and BBA the slave.
Each pin which uses the SPI bus has the following common functions.
S1M8656A can be used to power down the TCXO/N block using the SPI bus when the CDMA is asleep (CDMA
SLEEP). This mode, installed to minimize the product consumption power, is entered by setting a specific bit
(PWRDWN) in the CLK_GEN_MODE register to '1'. The current in the sleep mode reduces from 300uA to
10uA. The SEN(PIN26) pins decide on whether the product will used the SPI bus or parallel control inputs; if it is
in low, then the pins the parallel control input functions, IDLEB, FMB, and SLEEPB, but if in high then these pins
execute the SPI bus functions, STB, DATA, and CLK. This product does not require any external time constants
in initializing the internal register because it can use the internal reset function. Figure. 10 shows the serial bus
connection.
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The STB(STROBE) for the serial bus start signal is used to initialize serial data transmission.
This pin is used with the IDLEB function in manual mode and designated the IDLB/STB pin.
Serial BUS DATA is used for the bidirection data input /output at serial data transmission.
This pin is used with the FMB function in parallel mode and designated the FMB/DATA pin.
Because it is an open drain type pin, it requires the pull-up resistance of approx. 8k .
Serial BUS CLK is used to synchronize the data input/output at serial data transmission.
This pin is used with the SLEEPB function in manual mode and designated the SLEEPB/CLK pin.
S1M8656A
S1M8657
CLK/SLEEPB
SEL0/PAON
STB/IDLEB
STB/IDLEB
Figure 10. Serial Bus connection
DATA/FMB
DATA/FMB
CLK/SEL1
SLOT
SEN
SEN
8k
SLEEPB
SBST/ADC_ENA
SBCK/ADC_CLK
SBDT/ADC_DATA
PAON
V
DD
MODEM
RX IF/BBA WITH AGC