1 idtqs3r245 high-speed cmos quickswitch 8-bit low resistance bus switch industrial temperature range november 1999 1999 integrated device technology, inc. dsc-5546/- c idtqs3r245 industrial temperature range quickswitch ? products high-speed cmos quickswitch 8-bit low resistance bus switch description: the qs3r245 provides a set of eight high-speed cmos ttl-compatible bus switches in a pinout compatible with 74fct245, 74f245, 74als/as/ ls245 8-bit transceivers. the low on resistance of the qs3r245 allows inputs to be connected to outputs without adding propagation delay and without generating additional ground bounce noise. the output enable ( oe ) signal turns the switches on similar to the oe signal of the 74245. the low on resistance of qs3r245 makes it ideal for pci hot docking applications. quickswitch devices provide an order of magnitude faster speed than conventional logic devices. the qs3r245 is characterized for operation at -40c to +85c. b 0 oe a 0 b 1 a 1 b 2 a 2 b 3 a 3 b 4 a 4 b 5 a 5 b 6 a 6 b 7 a 7 functional block diagram features: - enhanced n channel fet with no inherent diode to vcc - 2.5 w bidirectional switches connect inputs to outputs - pin compatible with 74f245, 74fct245, and 74fct245t - zero propagation delay, zero ground bounce - undershoot clamp diodes on all switch and control inputs - ttl-compatible control inputs - available in soic and qsop packages applications - hot-swapping and hot-docking (low resistance for pci and compact pci applications) - bus switching and isolation - voltage translation (5v to 3.3v) - capacitance reduction and isolation - power conservation - logic replacement (data processing) - clock gating
2 industrial temperature range idtqs3r245 high-speed cmos quickswitch 8-bit low resistance bus switch pin configuration 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 nc a 0 a 1 a 2 a 3 a 4 a 5 a 6 a 7 gnd v cc oe b 0 b 1 b 2 b 3 b 4 b 5 b 6 b 7 so20-2 so20-8 soic/ qsop top view absolute maximum ratings (1) symbol description max. unit v term (2) supply voltage to ground C 0.5 to +7 v v term (3) dc switch voltage v s C 0.5 to +7 v v term (3) dc input voltage v in C 0.5 to +7 v v ac ac input voltage (pulse width 20ns) -3 v i out dc output current 120 ma p max maximum power dissipation .5 w t stg storage temperature C 65 to +150 c notes: 1. stresses greater than those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. 2. vcc terminals. 3. all terminals except vcc. capacitance (t a = +25 o c, f = 1.0mhz, v in = 0v, v out = 0v) pins typ. max. (1) unit control inputs 3 4 pf quickswitch channels (switch off) 5 6 pf note: 1. this parameter is guaranteed but not production tested. pin description pin names description oe output enable an data i/os bn data i/os function table (1) oe function h disconnected lan = bn note: 1. h = high volta g e level l = low volta g e level
3 idtqs3r245 high-speed cmos quickswitch 8-bit low resistance bus switch industrial temperature range r on (ohms) v in (volts) typical on resistance vs v in at v cc = 5v 16 14 12 10 8 6 4 2 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 dc electrical characteristics over operating range following conditions apply unless otherwise specified: industrial: t a = -40c to +85c, v cc = 5.0v 10% symbol parameter test conditions min. typ. (1) max. unit v ih input high voltage guaranteed logic high for control pins 2 v v il input low voltage guaranteed logic low for control pins 0.8 v i in input leakage current (control inputs) 0v v in vcc 1 m a i oz off-state current (hi-z) 0v v out vcc, switches off 0.001 1 m a r on switch on resistance vcc = min., v in = 0v , i on = 30ma 2.5 5 w r on switch on resistance vcc = min., v in = 2.4v , i on = 15ma 48.5 w v p pass voltage (2) v in = vcc = 5v, i out = -5 m a 3.7 4 4.3 v notes: 1. typical values are at v cc = 5.0v, t a = 25c. 2. pass voltage is guaranteed but not production tested.
4 industrial temperature range idtqs3r245 high-speed cmos quickswitch 8-bit low resistance bus switch power supply characteristics symbol parameter test conditions (1) max. unit i ccq quiescent power supply current v cc = max., v in = gnd or vcc, f = 0 3 m a d i cc power supply current per control input high (2) v cc = max., v in = 3.4v, f = 0 2.5 ma i ccd dynamic power supply current per mhz (3) v cc = max., a and b pins open control input toggling at 50% duty cycle 0.25 ma/mhz notes: 1. for conditions shown as min. or max., use the appropriate values specified under dc electrical characteristics. 2. per tll driven input (v in = 3.4v, control inputs only). a and b pins do not contribute to d icc . 3. this current applies to the control inputs only and represents the current required to switch internal capacitance at the sp ecified frequency. the a and b inputs generate no significant ac or dc currents as they transition. this parameter is guaranteed but not production tes ted. switching characteristics over operating range t a = -40c to +85c, v cc = 5.0v 10% c load = 50pf, r load = 500 w unless otherwise noted. symbol parameter min. (1) typ. max. unit t plh t phl data propagation delay (2,3) an to/from bn 0.12 (3) ns t pzl t pzh switch turn-on delay oe to an/bn 0.5 5.6 ns t plz t phz switch turn-off delay (2) oe to an/bn 0.5 4.5 ns notes: 1. minimums are guaranteed but not production tested. 2. this parameter is guaranteed but not production tested. 3. the bus switch contributes no propagation delay other than the rc delay of the on resistance of the switch and the load cap acitance. the time constant for the switch alone is of the order of 0.12ns for c l = 50pf. since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very little propagation delay to the system. pr opagation delay of the bus switch, when used in a system, is determi ned by the driving circuit on the driving side of the switch and its interaction with the load on the driven side.
5 idtqs3r245 high-speed cmos quickswitch 8-bit low resistance bus switch industrial temperature range ordering information idtqs xxxxx xx package device type blank industrial (-40c to +85c) small outline ic (so20-2) quarter size outline package (so20-8) so q 3r245 high speed quickswitch 8-bit low resistance bus switch x process corporate headquarters for sales: 2975 stender way 800-345-7015 or 408-727-6116 santa clara, ca 95054 fax: 408-492-8674 www.idt.com* *to search for sales office near you, please click the sales button found on our home page or dial the 800# above and press 2. the idt logo, quickswitch, and synchroswitch are registered trademarks of integrated device technology, inc.
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