1 idtqs32257 high-speed cmos quickswitch quad 2:1 mux/demux industrial temperature range august 2001 2001 integrated device technology, inc. dsc-5750/1 c idtqs32257 industrial temperature range quickswitch ? products high-speed cmos quickswitch quad 2:1 mux/demux description: the qs32257 is a high-speed cmos lvttl-compatible quad 2:1 multiplexer/demultiplexer. the qs32257 is a function and pinout compatible quickswitch version of the 74f257, 74fct257, and the 74als/as/ls257 quad 2:1 multiplexers. the qs32257 has 25 w series resistors to reduce ground noise. mux/demux devices provide an order of magnitude faster speed than equivalent logic devices. the qs32257 is characterized for operation at -40c to +85c. s e y a i 0a i 1a y b y c y d i 0b i 1b i 0c i 1c i 0d i 1d functional block diagram features: - enhanced n channel fet with no inherent diode to vcc - 5 w bidirectional switches connect inputs to outputs - pin compatible with the 74f257, 74fct257, and 74fct257t - zero propagation delay, zero ground bounce - undershoot clamp diodes on all switch and control inputs - ttl-compatible control inputs - 25 w resistors for low noise - available in soic, qsop, and s1 packages applications - logic replacement - video, audio, graphics switching, muxing - hot-swapping, hot-docking - voltage translation (5v to 3.3v) - bus funneling
2 industrial temperature range idtqs32257 high-speed cmos quickswitch quad 2:1 mux/demux pin configuration qsop/ soic/ s1 top view 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 s i 0a i 1a y a gnd v cc e i 0b i 1b y b i 0d i 1d y d i 0c i 1c y c so16-1 so16-7 so16-8 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 (t a = 85 c) 0.5 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 pins 4 5 pf quickswitch channels demux 5 7 pf (switch off) mux 8 9 pf note: 1. this parameter is guaranteed but not production tested. pin description pin names i/o description ixx i data inputs s i select input e i enable input y a - y d o data outputs function table (1) enable outputs ess 1 s 0 y a y b function h x hi-z hi-z hi-z hi-z disconnected lli 0a i 0b i 0c i 0d select 0 lhi 1a i 1b i 1c i 1d select 1 note: 1. h = high volta g e level l = low volta g e level x = dont care z = hi g h-impedence
3 idtqs32257 high-speed cmos quickswitch quad 2:1 mux/demux industrial temperature range r on (ohms) v in (volts) typical on resistance vs v in at v cc = 5v 80 70 60 50 40 30 20 10 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 5% 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 1 m a r on switch on resistance vcc = min., v in = 0v , i on = 30ma 20 28 40 w r on switch on resistance vcc = min., v in = 2.4v , i on = 15ma 20 35 48 w v p pass voltage (2) v in = vcc = 5v, i out = -5 m a 3.7 4 4.2 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 idtqs32257 high-speed cmos quickswitch quad 2:1 mux/demux 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 1.5 ma i ccd dynamic power supply current per mhz (3) v cc = max., i and y pins open control inputs 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). i and y 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 i and y 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 5% 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) in to y 1.25 (3) ns t pzh t pzl switch turn-on delay sn to y 0.5 6.2 ns t pzh t pzl switch turn-on delay en to y 0.5 5.8 ns t phz t plz switch turn-off delay (2) en to y, sn to y 0.5 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 1.25ns 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 idtqs32257 high-speed cmos quickswitch quad 2:1 mux/demux industrial temperature range ordering information idtqs xxxxx xx package device type small outline ic (so16-1) quarter size outline package (so16-7) quarter size outline package (so16-8) so q s1 32257 high speed cmos qui ckswitch 8-bit bus switch 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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