Texas Instruments LMK00308EVM, Руководство пользователя

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4
LMK00308EVM User’s Guide
March 2012
3. Quick Setup
To quickly set up and operate the board with basic equipment, refer to the setup procedure below and test
setup shown in
Figure 2
.
LMK0030x
EVALUATION
MODULE
C
L
K
in
X
C
L
K
in
X
*
VCC_EXT
GND
Bank A Outputs
(LVPECL default)
R
E
F
o
u
t
(L
V
C
M
O
S
)
Bank B Outputs
(LVPECL default)
Bottom side:
25 MHz Crystal
(Default Input)
CLKoutBn
CLKoutBn* CLKoutAn
CLKoutAn*
O-SCOPE
(50
W
inputs)
50
W
TERM
50
W
TERM
Note: Terminate unused
output traces (or disconnect
from output pin on PCB)
CLOCK
SOURCE
(OPTIONAL)
5
0
W
T
E
R
M
4-6 V
GND
POWER
SUPPLY
Figure 2: LMK00308 Evaluation Board Quick Start Setup
1. Verify the output mode control switches, S1[1:5], match the states shown in
Table 1
to reflect the default
output clock interfaces configured on the EVM.
Table 1: Default Clock Output Modes
SW Position/Name SW State Default Clock Output Modes
S1[1] / CLKoutB_Type1 OFF
Bank B outputs are LVDS
S1[2] / CLKoutB_Type0 ON
S1[3] / CLKoutB_Type1 OFF
Bank A outputs are LVPECL
S1[4] / CLKoutB_Type0 OFF
S1[5] / REFout_EN ON REFout (CMOS) enabled
2. Connect a 4
– 6 V power supply to VCC_EXT and GND terminals of the power block labeled J2. This powers
the on-board LDO regulator to supply 3.3 V to the VCC and VCCO rails of the IC. Both VCC & VCCO status
LEDs should be lit green when ON.
3. Set the desired clock input using the input selection control switches, S1[6:7], per
Table 2
. The onboard 25
MHz crystal (Y1) can be selected, so an external clock source is not required. A differential clock source can
be connected to SMAs labeled CLKin0/0* or CLKin1/1*. By default, these differential inputs are AC coupled
and terminated near the device with 100 ohms differential. To configure the EVM for a single-ended input,
refer to the
Clock Inputs
section.