8-bit transceive r cy74fct2245t sccs037 - july 1994 - revised march 2000 data sheet acquired from cypress semiconductor corporation. data sheet modi?ed to remove devices not offered. copyright ? 2000, texas instruments incorporated features ? function and pinout compatible with fct and f logic ? 25 w output series resistors to reduce transmission line re?ection noise ? fct-c speed at 4.1 ns max. fct-a speed at 4.6 ns max. ? edge-rate control circuitry for signi?cantly improved noise characteristics ? power-off disable feature ? fully compatible with ttl input and output logic levels ? esd > 2000v ? sink current 12 ma source current 15 ma ? extended commercial temp. range of C40?c to +85?c ? three-state outputs functional description the fct2245t contains eight non-inverting, bidirectional buffers with three-state outputs intended for bus oriented applications. on-chip termination resistors have been added to the outputs to reduce system noise caused by reflections. for this reason, the fct2245t can be used in an existing design to replace the fct245t. the fct2245t current sinking capability is 12 ma at the a and b ports. the transmit/receive (t/ r) input determines the direction of data flow through the bidirectional transceiver. transmit (active high) enables data from a ports to b ports; receive (active low) enables data from b ports to a ports. the output enable ( oe) input, when high, disables both the a and b ports by putting them in a high z condition. the outputs are designed with a power-off disable feature to allow for live insertion of boards. function table [1] inputs output oe t/ r l l bus b data to bus a l h bus a data to bus b h x high z state note: 1. h = high voltage level. l = low voltage level. x = dont care. logic block diagram pin configurations fct2245t C1 a 0 a 1 a 2 a 3 a 4 a 5 a 6 a 7 oe b 0 b 1 b 2 b 3 b 4 b 5 b 6 b 7 t/ r 1 2 3 4 5 6 7 8 9 10 11 12 16 17 18 19 20 13 14 v cc fct2245t C3 15 top view a 0 a 1 a 2 a 3 a 4 a 5 a 6 a 7 oe b 0 b 1 b 2 b 3 b 4 b 5 b 6 b 7 t/ r gnd dip/soic/qsop
cy74fct2245t 2 maximum ratings [2,3] (above which the useful life may be impaired. for user guide- lines, not tested.) storage temperature .................................C65 c to +150 c ambient temperature with power applied .............................................C65 c to +135 c supply voltage to ground potential ............... C0.5v to +7.0v dc input voltage............................................ C0.5v to +7.0v dc output voltage ......................................... C0.5v to +7.0v dc output current (maximum sink current/pin) ...... 120 ma power dissipation .......................................................... 0.5w static discharge voltage............................................>2001v (per mil-std-883, method 3015) operating range range range ambient temperature v cc commercial t, at, ct C40 c to +85 c 5v 5% electrical characteristics over the operating range parameter description test conditions min. typ. [5] max. unit v oh output high voltage v cc =min., i oh =C15 ma coml 2.4 3.3 v v ol output low voltage v cc =min., i ol =12 ma coml 0.3 0.55 v r out output resistance v cc =min., i ol =12 ma coml 20 25 40 w v ih input high voltage 2.0 v v il input low voltage 0.8 v v h hysteresis [6] all inputs 0.2 v v ik input clamp diode voltage v cc =min., i in =C18 ma C0.7 C1.2 v i i input high current v cc =max., v in =v cc 5 m a i ih input high current v cc =max., v in =2.7v 1 m a i il input low current v cc =max., v in =0.5v 1 m a i os output short circuit current [7] v cc =max., v out =0.0v C60 C120 C225 ma i off power-off disable v cc =0v, v out =4.5v 1 m a capacitance [6] parameter description test conditions typ. [5] max. unit c in input capacitance 5 10 pf c out output capacitance 9 12 pf notes: 2. unless otherwise noted, these limits are over the operating free-air temperature range. 3. unused inputs must always be connected to an appropriate logic voltage level, preferably either v cc or ground. 4. t a is the instant on case temperature. 5. typical values are at v cc =5.0v, t a =+25?c ambient. 6. this parameter is speci?ed but not tested. 7. not more than one output should be shorted at a time. duration of short should not exceed one second. the use of high-speed test apparatus and/or sampl e and hold techniques are preferable in order to minimize internal chip heating and more accurately re?ect operational values. otherwise prolonged sh orting of a high output may raise the chip temperature well above normal and thereby cause invalid readings in other parametric tests. in any sequence of parameter tests, i os tests should be performed last.
cy74fct2245t 3 power supply characteristics parameter description test conditions typ. [5] max. unit i cc quiescent power supply current v cc =max., v in < 0.2v, v in > v cc C0.2v 0.1 0.2 ma d i cc quiescent power supply current (ttl inputs) v cc =max., v in =3.4v, [8] f 1 =0, outputs open 0.5 2.0 ma i ccd dynamic power supply current [9] v cc =max., one input toggling, 50% duty cycle, outputs open, t/ r= oe=gnd, v in < 0.2v or v in > v cc C0.2v 0.06 0.12 ma/mhz i c total power supply current [10] v cc =max., 50% duty cycle, outputs open, one bit toggling at f 1 =10 mhz, t/ r= oe=gnd, v in < 0.2v or v in > v cc C0.2v 0.7 1.4 ma v cc =max., 50% duty cycle, outputs open, one bit toggling at f 1 =10 mhz, t/ r= oe=gnd, v in =3.4v or v in =gnd 1.0 2.4 ma v cc =max., 50% duty cycle, outputs open, eight bits toggling at f 1 =2.5 mhz, t/ r= oe=gnd, v in < 0.2v or v in > v cc C0.2v 1.3 2.6 [11] ma v cc =max., 50% duty cycle, outputs open, eight bits toggling at f 1 =2.5 mhz, t/ r= oe=gnd, v in =3.4v or v in =gnd 3.3 10.6 [11] ma notes: 8. per ttl driven input (v in =3.4v); all other inputs at v cc or gnd. 9. this parameter is not directly testable, but is derived for use in total power supply calculations. 10. i c =i quiescent + i inputs + i dynamic i c =i cc + d i cc d h n t +i ccd (f 0 /2 + f 1 n 1 ) i cc = quiescent current with cmos input levels d i cc = power supply current for a ttl high input (v in =3.4v) d h = duty cycle for ttl inputs high n t = number of ttl inputs at d h i ccd = dynamic current caused by an input transition pair (hlh or lhl) f 0 = clock frequency for registered devices, otherwise zero f 1 = input signal frequency n 1 = number of inputs changing at f 1 all currents are in milliamps and all frequencies are in megahertz. 11. values for these conditions are examples of the i cc formula. these limits are speci?ed but not tested.
cy74fct2245t 4 ] switching characteristics over the operating range [12] parameter description fct2245t fct2245at fct2245ct unit fig. no. [13] commercial commercial commercial min. max. min. max. min. max. t plh t phl propagation delay a n to b n or b n to a n 1.5 7.0 1.5 4.6 1.5 4.1 ns 1, 3 t pzh t pzl output enable time 1.5 9.5 1.5 6.2 1.5 5.8 ns 1, 7, 8 t phz t plz output disable time 1.5 7.5 1.5 5.0 1.5 4.5 ns 1, 7, 8 ordering informationfct2245t speed (ns) ordering code package name package type operating range 4.1 cy74fct2245ctqct q5 20-lead (150-mil) qsop commercial cy74fct2245ctsoc/soct s5 20-lead (300-mil) molded soic 4.6 cy74fct2245atpc p5 20-lead (300-mil) molded dip commercial CY74FCT2245ATQCT q5 20-lead (150-mil) qsop cy74fct2245atsoc/soct s5 20-lead (300-mil) molded soic 7.5 cy74fct2245tqct q5 20-lead (150-mil) qsop commercial cy74fct2245tsoc/soct s5 20-lead (300-mil) molded soic notes: 12. minimum limits are speci?ed but not tested on propagation delays. 13. see parameter measurement information in the general information section.
cy74fct2245t 5 package diagrams 20-lead (300-mil) molded dip p5 20-lead quarter size outline q5
cy74fct2245t 6 package diagrams (continued) 20-lead (300-mil) molded soic s5
important notice texas instruments and its subsidiaries (ti) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. all products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. ti warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with ti's standard warranty. testing and other quality control techniques are utilized to the extent ti deems necessary to support this warranty. specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. certain applications using semiconductor products may involve potential risks of death, personal injury, or severe property or environmental damage (acritical applicationso). ti semiconductor products are not designed, authorized, or warranted to be suitable for use in life-support devices or systems or other critical applications. inclusion of ti products in such applications is understood to be fully at the customer's risk. in order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. ti assumes no liability for applications assistance or customer product design. ti does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of ti covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. ti's publication of information regarding any third party's products or services does not constitute ti's approval, warranty or endorsement thereof. copyright ? 2000, texas instruments incorporated
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