Si5xx-EVB
1.2. Voltage Control for VCXOs
1. Functional Description
The voltage control (V ) input of the Si55x device is
C
The Si5xx-EVB provides access to all signals for
configuring and operating the device. This board allows
evaluation of the Si55x VCXO device either by itself
(open-loop) or within a prototype PLL (closed-loop). The
performance of the Si53x XO device can also be
evaluated on this board (the Vc port is not used for XO
devices).
conveniently accessible through an SMA jack (J3) but
can also be driven (and observed) through 100 mil-
centered posts (JP4). For prototyping purposes, two
0603 solder pads are located near the device V input
C
(R3 and C3). A traditional PLL might use these as a
single-time-constant low-pass filter (RC filter). The EVB
is shipped with a 0 Ω resistor soldered at R3; C3 is left
open. The voltage control input is not used for XO
devices.
Table 1. Jumper Control
Part Type
JP1
JP2
JP3
JP4
1.3. Output Clock
Si530
Si532
Si534
Si550
Si552
Si554
Notes:
N/A
N/A
N/A
N/A
OE
OE
N/A
Freq Sel
N/A
Because the Si55x/Si53x devices can support an
LVPECL buffer type (in addition to LVDS and CMOS),
pulldown resistors (R1 and R2) are available for proper
output biasing. For LVPECL buffers, biasing can be
achieved through a variety of equivalent circuits; the
Si5xx-EVB allows for 130 Ω pulldown resistors. After
the output biasing, the high-speed outputs are dc-
blocked for connection to differently biased inputs, such
as standard test equipment or a phase detector EVB.
Please review “1.4. Preparing the EVB” for non-LVPECL
devices.
Freq Sel1 Freq Sel2
OE
N/A
N/A
N/A
N/A
OE
V
V
V
C
C
C
Freq Sel
OE
Freq Sel1 Freq Sel2
1. With jumper(s) installed, signal(s) are driven low.
2. With jumper(s) not installed, signal(s) are pulled high.
1.1. Power Supply
1.4. Preparing the EVB
The Si55x/Si53x devices support operation from
nominal voltages of 1.8, 2.5, and 3.3 V. Review the
device data sheet and part number for allowed
configurations of output buffer type and device power
supply.
By default, the evaluation board is set up to accept
LVPECL configured devices. This configuration uses
130 Ω pull-down resistors to bias the LVPECL output
stage. If an LVDS, CMOS, or CML based device is to
be installed, the output biasing resistors, R1 and R2,
should be removed.
2
Rev. 0.14
SILICON [ SILICON ]
