Appendix E
19
SNAU219 – June 2017
Copyright © 2017, Texas Instruments Incorporated
Connecting Reference Pro
Jumpers FS1, FS0, OS, and OE can be used to configure the corresponding control pin to either high or
low state by strapping the center pin to
VDD
position (tie pins 2-3) or
GND
position (tie pins 1-2),
respectively. Connections from the
VDD
position to the device supply or from the
GND
position to the
ground plane are connected by 1.5-k
Ω
resistors.
Table 5. Output Frequency of LMK61PD0A2 (Reference Pro)
FS1
FS0
OUTPUT FREQUENCY (MHz)
0
0
100
0
NC
312.5
0
1
125
NC
0
106.25
NC
NC
156.25
NC
1
212.5
1
0
62.5
Table 6. OutputType of LMK61PD0A2 (Reference Pro)
OS
OE
OUTPUT TYPE
X
O
Disabled (PLL Functional)
0
1
LVPECL
NC
1
LVDS
1
1
HCSL
The OS pin is used to bias internal drivers and change the output type. It is imperative to match the output
termination passive components as shown on
with the output type from
lists component values for each configuration.
(1)
50
Ω
to V
CC
– 2? V termination is required on receiver.
(2)
100-
Ω
differential termination (R31) is provided on Reference Pro PCB. Removing the differential termination on the EVM is
possible if the differential termination is available on the receiver.
Table 7. Output Termination Schemes
OUTPUT FORMAT
COUPLING
COMPONENT
VALUE
LVPECL
AC
(default EVM
configuration)
R25, R28
0
Ω
R26, R29
150
Ω
C24, C25
0.01 uF
R27, R30, R31
DNP
DC
(1)
R25, R28, C24, C25
0
Ω
R26, R29, R27, R30, R31
DNP
LVDS
(2)
AC
R25, R28, R27, R30
0
Ω
R31
100
Ω
C24, C25
0.01 uF
R26, R29
DNP
DC
R25, R27, R28, R30, C24, C25
0
Ω
R31
100
Ω
R26, R29
DNP