1W40S11-23
W40S11-23
Clock Buffer/Driver
Features
Key Specifications
• Thirteen skew-controlled CMOS clock outputs
(SDRAM0:12)
• Supports three SDRAM DIMMs
• Ideal for high-performance systems designed around
Intel’s latest chip set
• SMBus serial configuration interface
• ClockSkew betweenanytwooutputsislessthan250ps
• 1- to 5-ns propagation delay
• DC to 133-MHz operation
• Single 3.3V supply voltage
• Low power CMOS design packaged in a 28-pin, 300-mil
SOIC (Small Outline Integrated Circuit), 28-pin, 173-mil
(Thin Shrink Small Outline Package), and 28-pin,
209-mil SSOP (Small Shrink Outline Package)
Supply Voltages:........................................... VDD = 3.3V±5%
Operating Temperature:.................................... 0°C to +70°C
Input Threshold: ..................................................1.5V typical
Maximum Input Voltage:.......................................VDD + 0.5V
Input Frequency:............................................... 0 to 133 MHz
BUF_IN to SDRAM0:12 Propagation Delay: ......1.0 to 5.0 ns
Output Edge Rate:.............................................. >1.5 V/ns
Output Clock Skew:.................................................. ±250 ps
Output Duty Cycle: .................................. 45/55% worst case
Output Impedance:...............................................15Ω typical
Output Type: ................................................CMOS rail-to-rail
Overview
The Cypress W40S11-23 is a low-voltage, thirteen-output
clock buffer. Output buffer impedance is approximately 15Ω,
which is ideal for driving SDRAM DIMMs.
Pin Configuration
Block Diagram
SOIC
SDATA
SCLOCK
Serial Port
Device Control
VDD
SDRAM0
SDRAM1
GND
1
2
3
4
5
6
7
8
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VDD
SDRAM0
SDRAM1
SDRAM2
SDRAM3
SDRAM4
SDRAM5
SDRAM6
SDRAM11
SDRAM10
GND
VDD
VDD
SDRAM2
SDRAM3
GND
SDRAM9
SDRAM8
GND
BUF_IN
SDRAM4
SDRAM5
SDRAM12
VDD
9
VDD
10
11
12
13
14
SDRAM7
SDRAM6
GND
GND
SCLOCK
SDRAM7
SDRAM8
SDRAM9
SDRAM10
SDRAM11
[1]
[1]
SDATA
BUF_IN
Note:
1. Internal pull-up resistor of 250K on SDATA and SCLOCK inputs
(not CMOS level).
SDRAM12
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
April 6, 2001