lmx2335u National Semiconductor Corporation, lmx2335u Datasheet - Page 30

• Manufacturer Part Number: lmx2335u
• Description: Pllatinum Ultra Low Power Dual Frequency Synthesizer For Rf Personal Communications
• Manufacturer: National Semiconductor Corporation

www.national.com
Test Setups
The block diagram above illustrates the setup required to
measure the LMX2336U device’s OSC
level. The same setup is used for the LMX2336TMEB/
LMX2336SLEEB Evaluation Boards. This setup is similar to
the f
now connected to the OSC
V
signal generator. The R counter is typically set to 1000, i.e.
RF1 R_CNTR Word = 1000 or RF2 R_CNTR Word = 1000.
The reference divider output is routed to the F
selecting the RF1 PLL R Divider Output word (F
Word = 1 or 9) in Code Loader. Similarly, a Universal
= 2 or 10) or the RF2 PLL R Divider Output word (F
CC
. The 51 Ω shunt resistor matches the OSC
IN
sensitivity setup except that the signal generator is
(Continued)
in
pin and both f
LMX2335U and LMX2336U OSC
in
IN
buffer sensitivity
pins are tied to
in
o
input to the
LD pin by
o
LD Word
o
LD
30
in
Counter is connected to the F
MHz reference output from the signal generator. The output
of the reference divider is monitored and should be equal to
OSC
Again, V
frequency and voltage level are then swept with the signal
generator. The measurements are repeated at different tem-
peratures, namely T
is reached when the frequency error of the divided input
signal is greater than or equal to 1 Hz.
The LMX2335U OSC
similar to the above test setup.
Sensitivity Test Setup
in
/ RF1 R_CNTR or OSC
CC
is swept from 2.7V to 5.5V. The OSC
A
= -40˚C, +25˚C, and +85˚C. Sensitivity
in
sensitivity test setup is very much
in
o
LD pin and is tied to the 10
/ RF2 R_CNTR.
10136741
in
input