MK1493-03B Datasheet, PDF (1/19 Pages) Integrated Device Technology – PCI CLOCK GENERATOR

PCI CLOCK GENERATOR
DATASHEET
MK1493-03B
Description
The MK1493-03B is a general purpose clock generator
device that provides an integrated clocking solution for PCI
/networking applications. It provides eight individually
programmable PCI clocks, one CPU clock, three additional
fixed PCI clocks, and a 25 MHz reference clock for LAN
support. This part incorporates IDT’s newest clock
technology, offering more robust features and functionality.
The device provides a gradual transition from its initial clock
frequency to the new one. Using a serially programmable
SMBus interface, the MK1493-03B can select the output
clock frequency and the transition from the original value to
the new value. The SMBus also allows each of the 8
programmable PCI clocks to be individually enabled and
disabled.
Block Diagram
Features
• Individually programmable (25, 33.33, 50, 66.66 MHz)
PCI clocks (Serial or external pin control)
• 1 CPU clock at 100/125 MHz Selectable; single
ended/differential selectable
• 1 Clock at 66.66 MHz
• 1 Clock at 66/71/83 MHz selectable
• 1 Clock at 50 MHz
• 25 MHz reference clock
• SMBus Programming
• Power-up default frequency can be selected through FS
inputs
• 25 MHz crystal or clock input required
• PCICLK cycle to cycle jitter <250 ps
• CPUCLK cycle to cycle jitter <150 ps
• 48-pin, 240 mil TSSOP Package
• Operating Voltage 3.3 V ±5%
• Commercial (0 to +70°C) and Industrial temperature
ranges (-40 to +85°C)
VDD
7
SCLK
SDATA
FS(0:7)_A ⁸
FS(0:7)_B ⁸
FS8
FS9
FS10
PLL
Divider
Buffer Circuits
SMBus Programmable
X1/CLK
25 MHz
X2
Clock Buffer/
Crystal
Ocsillator
External caps required
with crystal for accurate
tuning of the clock
7
GND
8 ^PCICLK(0:7)
Each PCI Output Clock
Individually Programmable
CPUCLK 100M/125M
CPUCLKB 100M/125M
CLK66M/71M/83M
CLK66M
CLK50M
REF25(25MHz)
IDT™ PCI CLOCK GENERATOR
1
MK1493-03B
REV H 051310