stcd1020 STMicroelectronics, stcd1020 Datasheet - Page 11

• Manufacturer Part Number: stcd1020
• Description: Multi-channel Clock Distribution Circuit
• Manufacturer: STMicroelectronics

3
3.1
Application information
Typical applications
The STCD1020, STCD1030 and STCD1040 distribute a source clock (for example, from
VCTCXO) to 2, 3 or 4 channel outputs. The typical application circuits using STCD1040 are
shown in
In
receiver and GSM transceiver separately.
In
power consumption, a Bluetooth system always has a clock request feature. If the Bluetooth
system does not require the clock, the clock request will disable the clock output.
The enable pins can also be connected to logic high to let the channel output always on. If
the channels of STCD1020, STCD1030 and STCD1040 are not used in the application, the
enable pins of the channels should be connected to ground on PCB.
Figure 7.
Figure
Figure
Figure 7
7, the clock from VCTCXO is distributed to the TD-SCDMA transmitter and
8, the buffer #4 output is fed into the Bluetooth system. In order to allow minimum
Typical application circuit using STCD1040 for RF ends of TD-
SCDMA/GSM dual mode mobile phone
and
VCTCXO
Figure 8
below.
STCD1040
MCLK
GND
V CC
V CC
CLK3
CLK2
CLK4
CLK1
EN3
EN4
EN2
EN1
selection
Mode
TD-SCDMA
receiver
TD-SCDMA
transmitter
transceiver
GSM
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