1 idtqs3257 high-speed cmos quickswitch quad 2:1 mux/demux industrial temperature range february 2001 2001 integrated device technology, inc. dsc-5756/7 c idtqs3257 industrial temperature range quickswitch ? products high-speed cmos quickswitch quad 2:1 mux/demux functional block diagram the idt logo is a registered trademark of integrated device technology, inc. features: ? enhanced n channel fet with no inherent diode to vcc ?5 ? ? ? ? ? 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 ? 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 description: the qs3257 is a high-speed cmos lvttl-compatible quad 2:1 multiplexer/demultiplexer. the qs3257 is a function and pinout compatible quickswitch version of the 74f257, 74fct257, and the 74als/as/ls257 quad 2:1 multiplexers. the low on resistance of the qs3257 allows inputs to be connected to outputs without adding propagation delay and without generating additional ground bounce noise. mux/demux devices provide an order of magnitude faster speed than equivalent logic devices. the qs3257 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
2 industrial temperature range idtqs3257 high-speed cmos quickswitch quad 2:1 mux/demux pin configuration soic/ qsop/ s1 top view note: 1. h = high voltage level l = low voltage level x = don't care z = high-impedance function table (1) enable outputs e sy a y b y c y d 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 symbol description max unit v term (2) supply voltage to ground ?0.5 to +7 v v term (3) dc switch voltage vs ?0.5 to +7 v v term (3) dc input voltage v in ?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 = 85c) 0.5 w t stg storage temperature ?65 to +150 c absolute maximum ratings (1) note: 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 = +25c, f = 1.0mh z , v in = 0v, v out = 0v) note: 1. this parameter is measured at characterization but not tested. pins typ. max. (1) unit control pins 4 5 pf quickswitch channels demux 5 7 pf (switch off) mux 8 9 pin description pin names i/o description i x x i data inputs s i select input e i enable input y a - y d o data outputs 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
3 idtqs3257 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 symbol parameter test conditions min. typ. (1) max. unit v ih input high level guaranteed logic high for control pins 2 ? ? v v il input low level guaranteed logic low for control pins ? ? 0.8 v i in input leakagecurrent (control inputs) (2) 0v v in v cc ?? 1a i oz off-state output current (hi-z) 0v v out v cc ?? 1a r on switch on resistance v cc = min., v in = 0v, i on = 30ma ? 5 7 ? v cc = min., v in = 2.4v, i on =15ma ? 10 15 v p pass voltage (2) v in = v cc = 5v, i out = -5 a 3.7 4 4.2 v dc electrical characteristics over operating range following conditions apply unless otherwise specified: industrial: t a = ?40c to +85c, v cc = 5.0v 5% notes: 1. typical values are at v cc = 5.0v, t a = 25c. 2. pass voltage is guaranteed but not production tested. 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
4 industrial temperature range idtqs3257 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 a ? 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 0.25 ma/mhz control inputs toggling at 50% duty cycle 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 ? icc. 3. this current applies to the control inputs only and represents the current required to switch internal capacitance at the spe cified frequency. the i and y inputs generate no significant ac or dc currents as they transition. this parameter is guaranteed but not production tested. switching characteristics over operating range t a = -40c to +85c, v cc = 5.0v 5%; c load = 50pf, r load = 500 ? unless otherwise noted. symbol parameter min. (1) typ. max. unit t plh data propagation delay (2,3) ? ? 0.25 (3) ns t phl ix to y t pzh switch turn-on delay 0.5 ? 5.2 ns t pzl sx to y t pzh switch turn-on delay 0.5 ? 4.8 ns t pzl ex to y t phz switch turn-off delay (2) 0.5 ? 5 ns t plz ex to y, sx to y 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 capacit ance. the time constant for the switch alone is of the order of 0.25ns for c l = 50pf. since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very littl e propagation delay to the system. propagation delay of the bus switch, when used in a system, is determined by the driving circuit on the driving si de of the switch and its interaction with the load on the driven side.
5 idtqs3257 high-speed cmos quickswitch quad 2:1 mux/demux industrial temperature range ordering information corporate headquarters for sales: for tech support: 2975 stender way 800-345-7015 or 408-727-6116 logichelp@idt.com santa clara, ca 95054 fax: 408-492-8674 (408) 654-6459 www.idt.com idtqs xxxxx xx package device type small outline ic quarter size outline package qsop - green small outline ic soic - green so q qg s1 s1g 3257 high speed cmos quickswitch quad 2:1 mux/demux
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