Datasheet

November 2013 LMK040xx Evaluation Board User’s Guide SNAU045A 17
Copyright © 2013, Texas Instruments Incorporated
www.ti.com
XTAL OSC Option PLL 1 Loop Filter
Supply Voltage
3.3 Volts
VCO Gain
10 MHz/Volt
Loop Filter
Components
C1 = 0
C2 = 6.8 nF
R2 = 2.7k ohms
C3 = 100 pF
C4 = 110 pF
R3 = 0.6k ohms
R4 = 0.2k ohms
Note: PLL Loop Bandwidth is a function of K, Kvco, N as well as loop components. Changing K and N will change the
loop bandwidth.
PLL1 and PLL2 Parameters for VCXO Option, 100 MHz.
100 MHz VCXO option PLL 1 Loop Filter
Phase Margin
50º
100 uA
Loop Bandwidth
20 Hz
Fcomp
1 MHz
Ref Clk Frequency
10 MHz
Output Frequency
100 MHz
(To PLL 2)
Supply Voltage
3.3 Volts
VCO Gain
4 kHz/Volt
Loop Filter
Components
C1 = 100 nF
C2 = 680 nF
R2 = 39k ohms
100 MHz VCXO Option PLL 2 Loop Filter
Phase Margin
79º
3200 uA
Loop Bandwidth
301 kHz
Fcomp
50 MHz
VCXO Frequency
100 MHz
(From PLL1)
Output Frequency
1500 MHz
Supply Voltage
3.3 Volts
VCO Gain
10 MHz/Volt
Loop Filter
Components
C1 = 0
C2 = 12 nF
R2 = 1.8 k ohms
C3 = 0
C4 = 10 pF
R3 = 0.6k ohms
R4 = 0.2k ohms
Note: PLL Loop Bandwidth is a function of K, Kvco, N as well as loop components. Changing K and N will change the
loop bandwidth.
PLL1 and PLL2 Parameters for VCXO Option, 61.44 MHz
61.44 MHz VCXO option PLL 1 Loop Filter
Phase Margin
50º
100 uA
Loop Bandwidth
20 Hz
Fcomp
1.024 MHz
Ref Clk Frequency
122.88 MHz
Output Frequency
61.44 MHz
(To PLL 2)
Supply Voltage
3.3 Volts
VCO Gain
2.5 kHz/Volt
Loop Filter
Components
C1 = 100 nF
C2 = 680 nF
R2 = 39k ohms