Texas Instruments High Performance Frequency Synthesizer System with Integrated VCO LMX25311515EVAL/NOPB LMX25311515EVAL/NOPB Hoja De Datos
Los códigos de productos
LMX25311515EVAL/NOPB
L M X 2 5 3 1 L Q 1 3 1 2 E E V A L U A T I O N B O A R D O P E R A T I N G I N S T R U C T I O N S
Loop Filter
Loop Bandwidth
8.1 kHz
K
φ
1440 uA (16X)
Phase Margin
61.2 deg
Fcomp
10 MHz
Crystal Frequency
10 MHz
Output Frequency
1450 – 1580 MHz (DIV2=0)
725 - 790 MHz (DIV2=1)
Supply Voltage
3.0 Volts
VCO Gain
4 - 7 MHz/Volt
VCO
CPout
op
en
100 nF
1K
Ω
100 pF
100 pF
20 KΩ
20 KΩ
Vtune
Quick Setup
• Install the CodeLoader software which is available at
.
• Attach the parallel or USB to parallel, port cable to the computer and the evaluation board.
• Connect 3.0 volts to the Vcc connector.
• Connect the Fout connector to a spectrum analyzer or phase noise analyzer.
• Connect a clean 10 MHz source to the OSCin pin. Typically, the 10 MHz output from the back
of the RF test equipment is a good source. Signal generators tend to be very noisy and should
be used with caution. If a signal generator is used, the signal generator phase noise
contribution can be reduced by setting the signal to 80 MHz and dividing this down to a phase
detector frequency of 10 MHz.
be used with caution. If a signal generator is used, the signal generator phase noise
contribution can be reduced by setting the signal to 80 MHz and dividing this down to a phase
detector frequency of 10 MHz.
• Set up the CodeLoader software
o Select the proper part from the menu as Select Part>PLL+VCO>LMX2531LQ1515E
o Select the proper mode from the Mode menu
o Load the part by pressing (Ctrl+L) or selecting Keyboard Controls->Load Device from
o Select the proper mode from the Mode menu
o Load the part by pressing (Ctrl+L) or selecting Keyboard Controls->Load Device from
the menu
• It is recommended to ensure proper communication with the device
o Click the REG_RST bit on the bits/pins page and observe the current go to 0 mA
o Unclick the REG_RST bit AND press (Ctrl+L). The current should be approximately
o Unclick the REG_RST bit AND press (Ctrl+L). The current should be approximately
35 mA
o If device does not respond to this, consult the troubleshooting section
o If device does not respond to this, consult the troubleshooting section
• When using the lower frequency band with divide by 2 enabled (DIV2=1), be aware that the
frequency programmed to the VCO is actually twice the output frequency of the device
because the VCO frequency is being divided by 2.
because the VCO frequency is being divided by 2.
3