L M K 0 3 0 0 0 C
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
8
Board Information
OSCin
By default the board is configured to use the on-board crystal oscillator. It is also possible to use the
board with a single ended or differential reference source at the OSCin port. Below are several
possible configurations for driving OSCin.
OSCin using on board crystal oscillator [default]
0 ohm
R8, R11, R20 [power to crystal oscillator], R109
39 ohm
R9 [can also be 0 ohm – depends on oscillator output power, 39 ohms
to be a voltage divider]
51 ohm
R15
0.1 uF
C35, C36 (C5 is a 0.1 uF 0402 cap which may be moved to C36)
Open C4,
C5
R7, R10, R12, R13, R14, R16, R17, R79, R112
Differential OSCin setup
0 ohm
R7, R8, R10, R13
100 ohm
R44
0.1 uF
C5, C35 (C36 is a 0.1 uF 0402 cap which may be moved to C5)
Open C4,
C36
R11, R12, R14, R15, R16, R79
R20 [remove power from crystal oscillator for noise reasons]
Single ended OSCin setup
0 ohm
R7, R8
51 ohm
R15
0.1 uF
C35, C36 (C5 is a 0.1 uF 0402 cap which may be moved to C36)
Open C4,
C5
R10, R11, R12, R13, R14, R16, R17, R79
R20 [remove power from crystal oscillator for noise reasons]
Fout
Fout allows direct access to the internal VCO before the clock distribution section. The EN_Fout bit
must be selected to enable Fout. A 3 dB pad is placed on R80, R81, and R82.
Loop Filter
R22 and R5 form a “resistor switch” which allows either one of two different loop filters to be
selected.
Loop Filter
Resistor
Switch
Loop Filter
Components
Default Loop
Bandwidth
Loop Filter #1
[default]
R22 Shorted
C1, C2, C2p, R2
59.1 kHz
Loop Filter #2
R5 Shorted
C1_AUX, C2_AUX,
C2p_AUX, R2_AUX
77 Hz