tm 74vhct245a octal buffer/line driver with 3-state outputs may 2007 ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 74vhct245a octal buffer/line driver with 3-state outputs features high speed: t pd = 5.4ns (typ.) at v cc = 5v power down protection on inputs and outputs low power dissipation: i cc = 4 a (max.) @ t a = 25? pin and function compatible with 74hct245 general description the vhct245a is an advanced high speed cmos octal bus transceiver fabricated with silicon gate cmos tech- nology. it achieves high speed operation similar to equiv- alent bipolar schottky ttl while maintaining the cmos low power dissipation. the vhct245a is intended for bidirectional asynchronous communication between data busses. the direction of data transmission is deter- mined by the level of the t/r input. the enable input can be used to disable the device so that the busses are effectively isolated. protection circuits ensure that 0v to 7v can be applied to the input and output (1) pins without regard to the supply voltage. these circuits prevent device destruction due to mismatched supply and input/output voltages. this device can be used to interface 5v to 3v systems and two supply systems such as battery back up. note: 1. outputs in off-state ordering information surface mount packages are also available on tape and reel. specify by appending the suffix letter ??to the ordering number. pb-free package per jeded j-std-020b. order number package number package description 74vhct245am m20b 20-lead small outline integrated circuit (soic), jedec ms-013, 0.300" wide 74vhct245asj m20d 20-lead small outline package (sop), eiaj type ii, 5.3mm wide 74vhct245amtc mtc20 20-lead thin shrink small outline package (tssop), jedec mo-153, 4.4mm wide
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 2 connection diagram pin description logic symbol ieee/iec truth table h = high voltage level l = low voltage level x = immaterial pin names description oe output enable input t/r tr ansmit/receive input a 0 ? 7 side a inputs or 3-state outputs b 0 ? 7 side b inputs or 3-state outputs inputs outputs oe t/r ll bus b data to bus a lh bus a data to bus b hx high-z state
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 3 absolute maximum ratings stresses exceeding the absolute maximum ratings may damage the device. the device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. in addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. the absolute maximum ratings are stress ratings only. recommended operating conditions (5) the recommended operating conditions table defines the conditions for actual device operation. recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. fairchild does not recommend exceeding them or designing to absolute maximum ratings. notes: 2. high or low state. i out absolute maximum rating must be observed. 3. when outputs are in off-state or when v cc = 0v. 4. v out < gnd, v out > v cc (outputs active). 5. unused inputs must be held high or low. they may not float. symbol parameter rating v cc supply voltage ?.5v to +7.0v v in dc input voltage ?.5v to +7.0v v out dc output voltage note 2 note 3 ?.5v to v cc + 0.5v ?.5v to +7.0v i ik input diode current ?0ma i ok output diode current (4) ?0ma i out dc output current ?5ma i cc dc v cc / gnd current ?5ma t stg storage temperature ?5? to +150? t l lead temperature (soldering, 10 seconds) 260? symbol parameter rating v cc supply voltage 4.5v to +5.5v v in input voltage 0v to +5.5v v out output voltage note 2 note 3 0v to v cc 0v to +5.5v t opr operating temperature ?0? to +85? t r , t f input rise and fall time, v cc = 5.0v ?0.5v 0ns/v ~ 20ns/v
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 4 dc electrical characteristics noise characteristics note: 6. parameter guaranteed by design. symbol parameter v cc (v) conditions t a = 25? t a = ?0? to +85? units min. typ. max. min. max. v ih high level input v oltage 4.5 2.0 2.0 v 5.5 2.0 2.0 v il low level input v oltage 4.5 0.8 0.8 v 5.5 0.8 0.8 v oh high level output v oltage 4.5 v in = v ih or v il i oh = ?0? 4.40 4.50 4.40 v i oh = ?ma 3.94 3.80 v ol low level output v oltage 4.5 v in = v ih or v il i ol = 50? 0.0 0.1 0.1 v i ol = 8ma 0.36 0.44 i oz 3-state output off-state current 5.5 v in = v ih or v il , v out = v cc or gnd ?.25 ?.5 ? i in input leakage current 0?.5 v in = 5.5v or gnd ?.1 ?.0 ? i cc quiescent supply current 5.5 v in = v cc or gnd 4.0 40.0 ? i cct maximum i cc / input 5.5 v in = 3.4v, other input = v cc or gnd 1.35 1.50 ma i off output leakage current (power down state) 0.0 v out = 5.5v 0.5 5.0 ? symbol parameter v cc (v) conditions t a = 25? units t yp. limits v olp (6) quiet output maximum dynamic v ol 5.0 c l = 50pf 1.2 1.6 v v olv (6) quiet output minimum dynamic v ol 5.0 c l = 50pf ?.2 ?.6 v v ihd (6) minimum high level dynamic input voltage 5.0 c l = 50pf 2.0 v v ild (6) maximum low level dynamic input voltage 5.0 c l = 50pf 0.8 v
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 5 ac electrical characteristics notes: 7. parameter guaranteed by design. t oslh = |t plh max ?t plh min |; t oshl = |t phl max ?t phl min | 8. c pd is defined as the value of the internal equivalent capacitance which is calculated from the operating current consumption without load. average operating current can be obtained by the equation: i cc (opr.) = c pd ?v cc ?f in + i cc / 8 (per f/f). the total c pd when n pcs. of the octal d flip-flop operates can be calculated by the equation: c pd (total) = 20 + 12n. symbol parameter v cc (v) conditions t a = 25? t a = ?0? to +85? units min. typ. max. min. max. t plh , t phl propagation delay time 5.0 ?0.5 c l = 15pf 4.9 7.7 1.0 8.5 ns c l = 50pf 5.4 8.7 1.0 9.5 t pzl , t pzh 3-state output enable time 5.0 ?0.5 r l = 1k ? c l = 15pf 9.4 13.8 1.0 15.0 ns c l = 50pf 9.9 14.8 1.0 16.0 t plz , t phz 3-state output disable time 5.0 ?0.5 r l = 1k ? c l = 50pf 10.1 15.4 1.0 16.5 ns t oslh , t oshl output to output s kew 5.0 ?0.5 (7) 1.0 1.0 ns c in input capacitance v cc = open 4 10 10 pf c out output capacitance v cc = 5.0v 13 pf c pd po w er dissipation capacitance (8) 16 pf
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 6 physical dimensions dimensions are in millimeters unless otherwise noted. figure 1. 20-lead small outline integrated circuit (soic), jedec ms-013, 0.300" wide pa ck ag e number m20b
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 7 physical dimensions (continued) dimensions are in millimeters unless otherwise noted. figure 2. 20-lead small outline package (sop), eiaj type ii, 5.3mm wide pa ck ag e number m20d
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 8 physical dimensions (continued) dimensions are in millimeters unless otherwise noted. figure 3. 20-lead thin shrink small outline package (tssop), jedec mo-153, 4.4mm wide pa ck ag e number mtc20
74vhct245a octal buffer/line driver with 3-state outputs ?997 fairchild semiconductor corporation www.fairchildsemi.com 74vhct245a rev. 1.3 9 trademarks the following are registered and unregistered trademarks fairchild semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. acex across the board. around the world. activearray bottomless build it now coolfet coreplus crossvolt ctl current transfer logic dome e 2 cmos ecospark ensigna fact quiet series fact fast fastr fps frfet globaloptoisolator gto hisec i-lo implieddisconnect intellimax isoplanar microcoupler micropak microwire motion-spm msx msxpro ocx ocxpro optologic optoplanar pacman pdp-spm pop power220 power247 poweredge powersaver power-spm powertrench programmable active droop qfet qs qt optoelectronics quiet series rapidconfigure rapidconnect scalarpump smart start spm stealth superfet supersot -3 supersot -6 supersot -8 syncfet tcm the power franchise tinyboost tinybuck tinylogic tinyopto tinypower tinywire trutranslation serdes uhc unifet vcx wire disclaimer fairchild semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function, or design. fairchild does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the rights of others. these specifications do not expand the terms of fairchild? worldwide terms and conditions, specifically the warranty therein, which covers these products. life support policy fairchild? products are not authorized for use as critical components in life support devices or systems without the express written approval of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems wh ich, (a) are intended for surgical implant into the body or (b) support or sustain life, and (c) whose failure to perform w hen properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. a critical component in any component of a life support, device, or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. product status definitions definition of terms datasheet identification product status definition advance information formative or in design this datasheet contains the design specifications for product development. specifications may change in any manner without notice. preliminary this datasheet contains preliminary data; supplementary data will be published at a later date. fairchild semiconductor reserves the right to make changes at any time without notice to improve design. no identification needed first production full production this datasheet contains final specifications. fairchild semiconductor reserves the right to make changes at any time without notice to improve design. obsolete not in production this datasheet contains specifications on a product that has been discontinued by fairchild semiconductor. the datasheet is printed for reference information only. rev. i27
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