2000 California Micro Devices Corp. All rights reserved.
4/00
215 Topaz Street, Milpitas, California 95035 Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
1
CALIFORNIA MICRO DEVICES
PACDN010
C0120497D
Features
Provides proper bus termination independent of
card loading conditions
Schottky diode technology; fast turn on
and reverse recovery characteristics
36 integrated diodes in a single package
offers 18 channel, dual rail clamping action
24-pin QSOP package saves board space and
eases layout in space critical bus termination
applications
Available in 24 pin TSSOP package for component
height constrained modules
Product Description
Reflections on high speed Memory Buses lead to undershoot and overshoot disturbances which may result in improper
system operation. Resistor terminations, when used to terminate high speed memory or data lines, increase power
consumption and degrade output (high) levels resulting in reduced noise immunity. Schottky diode termination is the best
overall solution for applications in which power consumption and noise immunity are critical considerations.
CAMDs P/Active DN010 Schottky Diode Memory Bus Terminator
is specifically designed to minimize undershoot/
overshoot disturbances caused by reflection noise on SDRAM bus lines as well as v2.1 66MHz PCI buses.
This highly integrated Schottky diode network provides very effective termination performance for high speed Memory Bus
lines under variable loading conditions. The packaged device supports up to 18 terminated lines each of which can be
simultaneously clamped to both ground and power supply rail.
Applications
SDRAM Memory Bus Termination
PCI v2.1 Bus Termination for Intel-based Pentium
and Pentium Pro systems
P/ACTIVE
TM
SCHOTTKY DIODE MEMORY BUS TERMINATOR
Refer to AP-201 Termination Application Note for
further information.
P/Active is a trademark of California Micro Devices Corp.
Pentium Pro is a registered trademark of Intel.
Covered by one or more of U.S. Pat. Nos. 5,355,014, 5,370,766, and 5,514,612 and other pending applications.
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VDD
VDD
VDD
GND
GND
GND
SCHEMATIC CONFIGURATION
2000 California Micro Devices Corp. All rights reserved.
4/00
215 Topaz Street, Milpitas, California 95035 Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
2
CALIFORNIA MICRO DEVICES
PACDN010
The absolute maximum ratings are limiting values, to be applied individually, beyond which the device may be permanently damaged. Functional
operation under any of these conditions is not guaranteed. Exposing the device to its absolute maximum rating may
affect its reliability.
Note 1:
The presence of a Schottky diode for clamping bus overshoots will cause additional delays of signal edges. These delays are the result of diode
characteristics such as forward voltage, diode capacitance and the reverse recovery phenomenon. The ground clamp diode is most critical,
particularly if VLSI circuits such as static or dynamic memories are directly connected to busses without any buffer stages. The incremental delay
observed on a positive edge following a negative transition that forward biased the Schottky diode is less than 800 pS. That represents less than
10% of the 125 MHz (8 nS period) bus cycle time.
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