FS7140-01 / FS7140-01g / FS7145 Programmable Phase-Locked Loop Clock Generator
1.0 Features
• Extremely flexible and low-jitter phase-locked loop (PLL)
frequency synthesis
• No external loop filter components needed
• 150MHz CMOS or 340MHz PECL outputs
• Completely configurable via I
2
C™-bus
• Up to four FS7140 or FS7145 can be used on a single
I
2
C-bus
• 3.3V operation
• Independent on-chip crystal oscillator and external
reference input
• Very low "cumulative" jitter
Data Sheet
2.0 Description
The FS7140 / FS7145 is a monolithic CMOS clock gen-
erator/regenerator IC designed to minimize cost and
component count in a variety of electronic systems. Via the I
2
C-
bus interface, the FS714x can be adapted to many clock
generation requirements.
The length of the reference and feedback dividers, their fine
granularity, and the flexibility of the post divider make the
FS714x the most flexible stand-alone phase-locked loop (PLL)
clock generator available.
3.0 Applications
SCL
SDA
ADDR0
VSS
XIN
XOUT
ADDR1
VDD
1
2
3
16
15
14
CLKN
CLKP
VDD
n/c
REF
VSS
n/c
IPRG
SCL
SDA
ADDR0
VSS
XIN
XOUT
ADDR1
VDD
1
2
3
16
15
14
CLKN
CLKP
VDD
SYNC
REF
VSS
n/c
IPRG
4
5
6
7
8
13
12
11
10
9
4
5
6
7
8
13
12
11
10
9
•
•
•
•
Precision frequency synthesis
Low-frequency clock multiplication
Video line-locked clock generation
Laser beam printers (FS7145)
Figure 1: Pin Configuration:
16-pin (0.150”) SOIC, 16-pin (5.3mm) SSOP
SYNC
(FS7145 only)
XIN
XOUT
Crystal
Oscillator
Reference
Divider
(N
R
)
REF
ADDR[1:0]
SCL
SDA
AMI Semiconductor - Rev. 3.0
www.amis.com
FS7140
FS7145
Sync
Control
IPRG
Loop
Filter
Phase-
Frequency
Detector
UP
Charge
Pump
DOWN
Voltage
Controlled
Oscillator
Post
Divider
(N
Px
)
CMOS/PECL
Output
CLKP
CLKN
Feedback
Divider
(N
F
)
I
2
C
Interface
Registers
FS7140 / FS7145
Figure 2: Device Block Diagram
1
AMI [ AMI SEMICONDUCTOR ]
