ICS843020-01 Datasheet, PDF (4/20 Pages) Integrated Circuit Systems – FEMTOCLOCKS-TM 680MHZ, CRYSTAL-TO- 3.3V DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS843020-01
FEMTOCLOCKS™ 680MHZ, CRYSTAL-TO-
3.3V DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER
TABLE 3A. PARALLEL AND SERIAL MODE FUNCTION TABLE
MR nP_LOAD M
Inputs
Conditions
N S_LOAD S_CLOCK S_DATA
H
X
XX
X
X
X Reset. Forces outputs LOW.
L
L
Data Data
X
L
↑
Data Data
L
L
H
XX
L
L
H
XX
↑
X
X
Data on M and N inputs passed directly to the M
divider and N output divider. TEST output forced LOW.
X
X
Data is latched into input registers and remains loaded
until next LOW transition or until a serial event occurs.
↑
Data
Serial input mode. Shift register is loaded with data on
S_DATA on each rising edge of S_CLOCK.
L
Data
Contents of the shift register are passed to the
M divider and N output divider.
L
H
XX
↓
L
Data M divider and N output divider values are latched.
L
H
XX
L
X
X Parallel or serial input do not affect shift registers.
L
H
XX
H
NOTE: L = LOW
H = HIGH
X = Don't care
↑ = Rising edge transition
↓ = Falling edge transition
↑
Data S_DATA passed directly to M divider as it is clocked.
TABLE 3B. PROGRAMMABLE VCO FREQUENCY FUNCTION TABLE WITH P = ÷1 (P_DIV = FLOAT)
VCO Frequency
(MHz)
M Divide
256
M8
128
M7
64
M6
32
M5
16
M4
8
M3
4
M2
2
M1
1
M0
575
23
0
0
0
0
1
0
1
1
1
•
•
•
•
•
•
•
•
•
•
•
600
24
0
0
0
0
1
1
0
0
0
•
•
•
•
•
•
•
•
•
•
•
675
27
0
0
0
0
1
1
0
1
1
NOTE 1: These M divide values and the resulting frequencies correspond to crystal or TEST_CLK input frequency
of 25MHz.
TABLE 3C. PROGRAMMABLE VCO FREQUENCY FUNCTION TABLE WITH P = ÷4 (P_DIV = 1)
VCO Frequency
(MHz)
M Divide
256
M8
128
M7
64
M6
32
M5
16
M4
8
M3
4
M2
2
M1
1
M0
575
92
0
0
1
0
1
1
1
0
0
•
•
•
•
•
•
•
•
•
•
•
600
96
0
0
1
1
0
0
0
0
0
•
•
•
•
•
•
•
•
•
•
•
675
108
0
0
1
1
0
1
1
0
0
NOTE 1: These M divide values and the resulting frequencies correspond to crystal or TEST_CLK input frequency
of 25MHz.
843020AY-01
www.icst.com/products/hiperclocks.html
4
REV. B APRIL 14, 2005