lmk03002c National Semiconductor Corporation, lmk03002c Datasheet - Page 14

• Manufacturer Part Number: lmk03002c
• Description: Precision Clock Conditioner With Integrated Vco
• Manufacturer: National Semiconductor Corporation

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the output path a fixed delay of approximately 400 ps is in-
curred in addition to the delay shown in the table below.
2.3.5 CLKoutX_EN bit -- Clock Output Enables
These bits control whether an individual clock output is en-
abled or not. If the EN_CLKout_Global bit (See 2.6.4) is set
2.5 REGISTER R13
2.5.1 VCO_C3_C4_LF[3:0] -- Value for Internal Loop Filter
Capacitors C3 and C4
These bits control the capacitor values for C3 and C4 in the
internal loop filter.
2.5.2 VCO_R3_LF[2:0] -- Value for Internal Loop Filter Resistor R3
These bits control the R3 resistor value in the internal loop filter. The recommended setting for VCO_R3_LF[2:0] = 0 for optimum
phase noise and jitter.
CLKoutX_DLY[3:0]
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
DIV4
0
1
VCO_C3_C4_LF[3:0]
12 to 15
10
11
Delay (ps)
0 (default)
0
1
2
3
4
5
6
7
8
9
1050
1200
1350
1500
1650
1800
1950
2100
2250
150
300
450
600
750
900
Not divided; Phase Detector Frequency
Divided by 4; Phase Detector Frequency > 20 MHz
Digital Lock Detect Circuitry Mode
14
0 (default)
C3 (pF)
to zero or if GOE pin is held low, all CLKoutX_EN bit states
will be ignored and all clock outputs will be disabled. See 1.8
for more information on CLKout states.
2.4 REGISTER R11
This register only has one bit and only needs to be pro-
grammed in the case that the phase detector frequency is
greater than 20 MHz and digital lock detect is used. Other-
wise, it is automatically defaulted to the correct values.
2.4.1 DIV4 -- High Phase Detector Frequencies and Lock
Detect
This bit divides the frequency presented to the digital lock de-
tect circuitry by 4. It is necessary to get a reliable output from
the digital lock detect output in the case of a phase detector
frequency frequency greater than 20 MHz.
100
100
100
150
150
50
50
50
CLKoutX_EN bit
0
0
0
Loop Filter Capacitors
0
1
Invalid
≤
10 (default)
GOE pin = High / No
EN_CLKout_Global
20 MHz (default)
C4 (pF)
110
110
110
160
160
110
60
10
10
60
60
Conditions
Connect
bit = 1
Disabled (default)
CLKoutX State
Enabled