california micro devices pacdn005 2/00 1 215 topaz street, milpitas, california 95035 tel: (408) 263-3214 fax: (408) 263-7846 www.calmicro.com ?2000 california micro devices corp. all rights reserved. features ? 36 integrated diodes in a single package offers 18 channel, dual rail clamping action ? provides proper bus termination independent of external line or card loading conditions ? schottky diode technology; excellent forward voltage and reverse recovery characteristics ? 24-pin qsop package saves board space and eases layout in space critical bus termination applications versus discrete approaches product description note: cmd?s p/active dn005 schottky diode high speed bus terminator is an upgraded version of the original pdn001 or ipec dn001 diode array. pacdn005 provides minimized lead inductance and parasitic capacitive effects (with added ground pins), improved forward voltage and crosstalk attributes, and excellent termination performance characteristics at high data transmission rates. the pacdn005 is recommended for all new designs. reflections on high speed data lines lead to undershoot and overshoot disturbances which may result in improper system operation. resistor terminations, when used to terminate high speed data lines, increase power consumption and degrade output (high) levels resulting in reduced noise immunity. schottky diode termination is the best overall solution for applica- tions in which power consumption and noise immunity are critical considerations. cmd?s p/active dn005 schottky diode high speed bus terminator ? is specifically designed to minimize undershoot/over- shoot disturbances caused by reflection noise on high speed bus lines such as v2.1 66mhz pci buses, all varieties of risc embedded processor/control local buses, synchronous dram, and other high speed memory bus termination applications. this highly integrated schottky diode network provides very effective termination performance for high speed data lines under variable loading conditions. the device supports up to 18 terminated lines per package ? each of which can be simulta- neously clamped to both ground and power supply rail. a typical bus termination application will utilize three pac dn005 devices to replace approximately 50 conventional schottky diode pairs; thus providing significant reductions in component and assembly costs, improvements in manufacturing efficiency and reliability, and savings in allocated board area for space- critical designs. applications ? pci v2.1 bus termination for intel-based pentium? and pentium pro systems ? local high speed bus termination for all popular risc and embedded microprocessor applications ? high speed memory and sdram memory bus termination p/active schottky diode high speed bus terminator refer to ap-201 termination application note for further information. schematic configuration 24 123456789101112 23 22 21 20 19 18 13 14 17 15 16 vdd vdd vdd gnd gnd gnd
california micro devices pacdn005 ?2000 california micro devices corp. all rights reserved. 215 topaz street, milpitas, california 95035 tel: (408) 263-3214 fax: (408) 263-7846 www.calmicro.com 2 2/00 standard specifications absolute maximum ratings parameter symbol rating supply voltage v dd -0.3v to +7v channel clamp current (continuous) i clamp 50ma operating temperature 0 o c to 70 o c storage temperature tstg -65 o c to +150 o c package power rating 1.00w, max. parameter conditions min typ max diode foward voltage to v dd i f = 16 ma 0.55v 0.70v i f = 50 ma 0.55v 0.70v 0.90v from gnd i f = 16 ma 0.50v 0.65v i f = 50 ma 0.50v 0.65v 0.85v reverse recovery time (see note 1) i f = 50ma (estimated) <400ps channel leakage 0 v in v dd 0.1a 5a input capacitance f = 1 mhz, v in = 2.5v, t a = 25 o c, v dd = 5.0v 5pf esd protection mil-std-883, method 3015 4kv the absolute maximum ratings are limiting values, to be applied individually, beyond which the device may be permanently damage d. functional operation under any of these conditions is not guaranteed. exposing the device to its absolute maximum rating may affect its reliability. package ordering part number pins style tubes t ape & reel part marking 24 qsop pacdn005q/t pacdn005q/r pacdn005q 24 soic wide pacdn005s/t pacdn005s/r pacdn005s standard part ordering information note 1: the test circuit depicts the schottky diodes in their typical application. the impact of a reverse recovery time is measured using a narrow pulse with 670- ps rise and fall times. this pulse propagates down a 60 cm, 54 ohm strip line fabricated on a multi-layer, controlled impedance printed circuit board. in testing the ground clamp diode, the negative going edge of the pulse causes a reflection which forces the diode under test to become forward biased. the positive going edge of the pulse attempts to pull this diode out of forward conduction. a reverse recovery phenomenon would cause a delay between the known arrival time of the positive edge and the observed edge due to the time it takes for the forward biased diode to actually become reversed biased. in this measurement, however, there is no observable difference and therefore no delay for the positive edge due to the presence of the diode. the waveforms are adjusted to individually test the ground and v dd clamps. see test circuit. test circuit. line length, pulse width and duty cycle are selected such as that only one reflection is involved in the measurement. v diode under test dd z,l 0 abt16244a pulse generator diode characteristics (t a = 0 o to 70 o c)
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