PRELIMINARY
ICS84025
Integrated
Circuit
Systems, Incꢀ
CRYSTAL-TO-LVCMOS / LVTTL
FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
GENERAL DESCRIPTION
FEATURES
The ICS84025 is a Crystal-to-LVCMOS/LVTTL • 6 LVCMOS/LVTTLoutputs
Frequency Synthesizer with Fanout Buffer and
a member of the HiPerClockS™ family of High
Performance Clock Solutions from ICS. The
VCO frequency is programmed in steps equal
• Crystal oscillator interface
HiPerClockS™
• Output frequency range: 53.125MHz to 125MHz
• Crystal input frequency: 25MHz and 25.5MHz
to the value of the crystal frequency. The VCO and
output frequency can be programmed using the feedback and
output frequency select pins. The low phase noise character-
istics of the ICS84025 make it an ideal clock source for Fibre
Channel 1 and Gigabit Ethernet applications.
• RMS phase jitter at 106.25, using a 25.5MHz crystal
(637KHz to 10MHz): 3.25ps
• Phase noise:
Offset
Noise Power
100Hz ................. -100 dBc/Hz
1KHz ................. -115 dBc/Hz
10KHz ................. -125 dBc/Hz
100KHz ................. -127 dBc/Hz
FUNCTION TABLE
Inputs
XTAL
Output Frequency
F_OUT
MR F_SEL1 F_SEL0
• 3.3V core, outputs may either be 3.3V, 2.5V or 1.8V
• 0°C to 70°C ambient operating temperature
1
0
0
0
0
X
0
0
1
1
X
0
1
0
1
LOW
25.5MHz
25.5MHz
25MHz
53.125MHz
106.25MHz
62.5MHz
• Industrial temperature information available upon request
25MHz
125MHz
BLOCK DIAGRAM
PIN ASSIGNMENT
VDDO
Q0
GND
Q1
VDDO
Q2
GND
Q3
VDDO
Q4
GND
Q5
1
2
3
4
24
23
22
21
20
19
18
F_SEL0
F_SEL1
MR
XTAL1
XTAL2
GND
VDDA
VDD
PLL_SEL
GND
XTAL1
OSC
XTAL2
0
Output
Divider
6
/
5
6
Q0:Q5
1
7
PLL
8
9
10
11
12
17
16
15
14
13
nc
VDDO
Feedback
Divider
ICS84025
24-Lead, 300-MIL SOIC
7.5mm x 15.33mm x 2.3mm body package
M Package
Top View
F_SEL1
PLL_SEL MR F_SEL0
The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial
product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.
84025EM
www.icst.com/products/hiperclocks.html
REV. A APRIL 16, 2003
1