LMX2335USLBX National Semiconductor, LMX2335USLBX Datasheet - Page 28

• Manufacturer Part Number: LMX2335USLBX
• Description: IC FREQ SYNTH DUAL 16LAMINATECSP
• Manufacturer: National Semiconductor
• Series: PLLatinum™r
• Type: PLL Frequency Synthesizerr

Specifications of LMX2335USLBX

• Pll: Yes with Bypass
• Input: CMOS, TTL
• Output: CMOS
• Number Of Circuits: 1
• Ratio - Input:output: 3:1
• Differential - Input:output: No/No
• Frequency - Max: 1.2GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-Laminate CSP
• Frequency-max: 1.2GHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: LMX2335USLBXTR

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Test Setups
The block diagram above illustrates the setup required to
measure the LMX2336U device’s RF1 charge pump sink
current. The same setup is used for the LMX2336TMEB/
LMX2336SLEEB Evaluation Boards. The RF2 charge pump
measurement setup is similar to the RF1 charge pump mea-
surement setup. The purpose of this test is to assess the
functionality of the RF1 charge pump.
This setup uses an open loop configuration. A power supply
is connected to V
of a signal generator, a 10 MHz signal is typically applied to
the f
detector. The 3 dB pad provides a 50 Ω match between the
PLL and the signal generator. The OSC
This establishes the other input to the phase detector. Alter-
natively, this input can be tied directly to the ground plane.
With the D
eter Analyzer in this way, the sink, source, and TRI-STATE
currents can be measured by simply toggling the Phase
Detector Polarity and Charge Pump State states in Code
Loader. Similarly, the LOW and HIGH currents can be mea-
sured by switching the Charge Pump Gain’s state between
1X and 4X in Code Loader.
IN
RF1 pin. The signal is one of two inputs to the phase
o
RF1 pin connected to a Semiconductor Param-
cc
and swept from 2.7V to 5.5V. By means
LMX2335U and LMX2336U Charge Pump Test Setup
in
pin is tied to V
cc
.
28
Let F
OSC
represent the frequency of the signal applied to the f
pin. The phase detector is sensitive to the rising edges of F
and F
pump turns ON and sinks current when the first rising edge
of F
pump continues to sink current indefinitely.
Toggling the Phase Detector Polarity state to negative
VCO characteristics allows the measurement of the RF1
charge pump source current. Likewise, selecting TRI-STATE
(TRI-STATE ID
Code Loader facilitates the measurement of the TRI-STATE
current.
The measurements are repeated at different temperatures,
namely T
The LMX2335U charge pump test setup is very much similar
to the above test setup.
p
in
r
p
is detected. Since F
represent the frequency of the signal applied to the
pin, which is simply zero in this case (DC), and let F
. Assuming positive VCO characteristics; the charge
A
= -40˚C, +25˚C, and +85˚C.
o
RF1 Bit = 1) for Charge Pump State in
r
has no rising edge, the charge
10136750
IN
RF1
p
r