CDB61884 Datasheet, PDF (5/22 Pages) Cirrus Logic – Octal T1/E1/J1 Line Interface Evaluation Board

CDB61884
2. BOARD COMPONENT DESCRIPTIONS
2.1 Power Connections
Power for the evaluation board is supplied by an
external +3.3 V DC power supply. A +5 V DC
power supply can also be connected to the on-board
control logic. The LED labeled “D3” will illumi-
nate when power is supplied to the on-board con-
trol logic.
– Connect the +3.3 VDC power supply to the +3V
binding post and the +5 VDC power supply to
the +5 V binding post if 5 Volt logic is required
– Jumper J13 shown in Figure 2 allows all the
external logic on the evaluation board to be
connected to either +3 V or +5 V binding post.
J13
3V
2.2 Master Clock Selection
In both hardware and host modes, the MCLK pin is
configured by placing a short block on one of the
positions of bed stake header J1. Figure 3 shows
the different positions of the J1 bed stake header.
MCLK
J1
Data Recovery Mode
MCLK
J1
On-board Oscillator
V LO G IC
5V
O n-board logic connected
to + 3 V b in d in g p o st
J13
3V
V LO G IC
5V
MCLK
MCLK
J1
J1
External Clock Source Receivers Powered Down
O n-board logic connected
to +5 V binding post
Figure 2. On-board Logic Power Selection
– To measure the current consumption of only
the CS61884 device, place a short block on
Jumper J13 to connect the Vlogic power
supplies to the +5 V binding post. This will
isolate the CS61884 device from all the on-
board logic, to allow the current measurement
to be made at the +3 V binding post.
Figure 3. Master Clock Selections
– A 2.048 MHz clock oscillator is provided on the
evaluation board for use as the on-board clock
source for all E1 modes.
– A 1.544 MHz clock oscillator is also provided
with the evaluation board for use as the on-
board clock source for the T1/J1 operation
modes.
– A BNC connector (labeled J16) provides the
connection for an external clock source.
DS485DB1
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