1/10 july 2001 n high speed: t pd = 10ns (typ.) at v cc =6v n low power dissipation: i cc =4 m a(max.) at t a =25 c n high noise immunity: v nih =v nil =28%v cc (min.) n symmetrical output impedance: |i oh |=i ol = 6ma (min) n balanced propagation delays: t plh @ t phl n wide operating voltage range: v cc (opr) = 2v to 6v n pin and function compatible with 74 series 245 description the m74hc245 is an advanced high-speed cmos octal bus transceiver (3-state) fabricated with silicon gate c 2 mos technology. this ic is intended for two-way asynchronous communication between data buses, and the direction of data transmission is determined by dir input. the enable input g can be used to disable the device so that the buses are effectively isolated. all inputs are equipped with protection circuits against static discharge and transient excess voltage. all floating bus terminals during high z state must be held high or low. m74hc245 octal bus transceiver with 3 state outputs (non inverted) pin connection and iec logic symbols order codes package tube t & r dip m74hc245b1r sop m74hc245m1r M74HC245RM13TR tssop m74hc245ttr tssop dip sop
m74hc245 2/10 input and output equivalent circuit pin description truth table x : don't care z : high impedance absolute maximum ratings absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditions is not implied (*) 500mw at 65 c; derate to 300mw by 10mw/ c from 65 cto85 c recommended operating conditions pin no symbol name and function 1 dir directional control 2, 3, 4, 5, 6, 7, 8, 9 a1 to a8 data inputs/outputs 18, 17, 16, 15, 14, 13, 12, 11 b1 to b8 data inputs/outputs 19 g output enable input 10 gnd ground (0v) 20 v cc positive supply voltage inputs function output g dir a bus b bus yn l l output input a = b l h input output b = a hxz zz symbol parameter value unit v cc supply voltage -0.5 to +7 v v i dc input voltage -0.5 to v cc + 0.5 v v o dc output voltage -0.5 to v cc + 0.5 v i ik dc input diode current 20 ma i ok dc output diode current 20 ma i o dc output current 35 ma i cc or i gnd dc v cc or ground current 70 ma p d power dissipation 500(*) mw t stg storage temperature -65 to +150 c t l lead temperature (10 sec) 300 c symbol parameter value unit v cc supply voltage 2to6 v v i input voltage 0 to v cc v v o output voltage 0 to v cc v t op operating temperature -55 to 125 c t r ,t f input rise and fall time v cc = 2.0v 0 to 1000 ns v cc = 4.5v 0 to 500 ns v cc = 6.0v 0 to 400 ns
m74hc245 3/10 dc specifications symbol parameter test condition value unit v cc (v) t a =25 c -40 to 85 c -55 to 125 c min. typ. max. min. max. min. max. v ih high level input voltage 2.0 1.5 1.5 1.5 v 4.5 3.15 3.15 3.15 6.0 4.2 4.2 4.2 v il low level input voltage 2.0 0.5 0.5 0.5 v 4.5 1.35 1.35 1.35 6.0 1.8 1.8 1.8 v oh high level output voltage 2.0 i o =-20 m a 1.9 2.0 1.9 1.9 v 4.5 i o =-20 m a 4.4 4.5 4.4 4.4 6.0 i o =-20 m a 5.9 6.0 5.9 5.9 4.5 i o =-6.0 ma 4.18 4.31 4.13 4.10 6.0 i o =-7.8 ma 5.68 5.8 5.63 5.60 v ol low level output voltage 2.0 i o =20 m a 0.0 0.1 0.1 0.1 v 4.5 i o =20 m a 0.0 0.1 0.1 0.1 6.0 i o =20 m a 0.0 0.1 0.1 0.1 4.5 i o =6.0 ma 0.17 0.26 0.33 0.40 6.0 i o =7.8 ma 0.18 0.26 0.33 0.40 i i input leakage current 6.0 v i =v cc or gnd 0.1 1 1 m a i oz high impedance output leakage current 6.0 v i =v ih or v il v o =v cc or gnd 0.5 5 10 m a i cc quiescent supply current 6.0 v i =v cc or gnd 44080 m a
m74hc245 4/10 ac electrical characteristics (c l = 50 pf, input t r =t f = 6ns) capacitive characteristics 1) c pd is defined as the value of the ic's internal equivalent capacitance which is calculated from the operating current consumption without load. (refer to test circuit). average operating current can be obtained by the following equation. i cc(opr) =c pd xv cc xf in +i cc /8 (per circuit) symbol parameter test condition value unit v cc (v) c l (pf) t a =25 c -40 to 85 c -55 to 125 c min. typ. max. min. max. min. max. t tlh t thl output transition time 2.0 50 25 60 75 90 ns 4.5 7121918 6.0 6101315 t plh t phl propagation delay time 2.0 50 33 90 115 135 ns 4.5 12 18 23 27 6.0 10 15 20 23 2.0 150 48 120 150 180 ns 4.5 16 24 30 36 6.0 14 20 26 31 t pzl t pzh high impedance output enable time 2.0 50 r l =1k w 48 150 190 225 ns 4.5 16 30 38 45 6.0 14 26 32 38 2.0 150 r l =1k w 63 180 225 270 ns 4.5 21 36 45 54 6.0 18 31 38 46 t plz t phz high impedance output disable time 2.0 50 r l =1k w 37 150 190 225 ns 4.5 17 30 38 45 6.0 15 26 32 38 symbol parameter test condition value unit v cc (v) t a =25 c -40 to 85 c -55 to 125 c min. typ. max. min. max. min. max. c in input capacitance dir, g 5 10 10 10 pf c i/out output capacitance an, bn 13 pf c pd power dissipation capacitance (note 1) 39 pf
m74hc245 5/10 test circuit c l = 50pf/150pf or equivalent (includes jig and probe capacitance) r 1 =1k w or equivalent r t =z out of pulse generator (typically 50 w ) waveform 1: propagation delay time (f=1mhz; 50% duty cycle) test switch t plh ,t phl open t pzl ,t plz v cc t pzh ,t phz gnd
m74hc245 6/10 waveform 2 : output enable and disable time (f=1mhz; 50% duty cycle)
m74hc245 7/10 dim. mm. inch min. typ max. min. typ. max. a1 0.254 0.010 b 1.39 1.65 0.055 0.065 b 0.45 0.018 b1 0.25 0.010 d 25.4 1.000 e 8.5 0.335 e 2.54 0.100 e3 22.86 0.900 f 7.1 0.280 i 3.93 0.155 l 3.3 0.130 z 1.34 0.053 plastic dip-20 (0.25) mechanical data p001j
m74hc245 8/10 dim. mm. inch min. typ max. min. typ. max. a 2.65 0.104 a1 0.1 0.2 0.004 0.008 a2 2.45 0.096 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.012 c 0.5 0.020 c1 45 (typ.) d 12.60 13.00 0.496 0.512 e 10.00 10.65 0.393 0.419 e 1.27 0.050 e3 11.43 0.450 f 7.40 7.60 0.291 0.300 l 0.50 1.27 0.020 0.050 m 0.75 0.029 s8 (max.) so-20 mechanical data po13l
m74hc245 9/10 dim. mm. inch min. typ max. min. typ. max. a 1.2 0.047 a1 0.05 0.15 0.002 0.004 0.006 a2 0.8 1 1.05 0.031 0.039 0.041 b 0.19 0.30 0.007 0.012 c 0.09 0.20 0.004 0.0089 d 6.4 6.5 6.6 0.252 0.256 0.260 e 6.2 6.4 6.6 0.244 0.252 0.260 e1 4.3 4.4 4.48 0.169 0.173 0.176 e 0.65 bsc 0.0256 bsc k0 8 0 8 l 0.45 0.60 0.75 0.018 0.024 0.030 tssop20 mechanical data c e b a2 a e1 d 1 pin 1 identification a1 l k e 0087225c
m74hc245 10/10 information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringe ment of patents or other righ ts of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specifications mentioned in this pub lication are subject to change without notice. thi s pub lication supersedes and replaces all information previously supplied. stmicroelectronics prod ucts are not authori zed for use as critical components in life suppo rt devices or systems without express written approval of stmicroelectronics. ? the st logo is a registered trademark of stmicroelectronics ? 2001 stmicroelectronics - printed in italy - all rights reserved stmicroelectronics group of companies australia - brazil - china - finland - france - germany - hong kong - india - italy - japan - malaysia - malta - morocco singapore - spain - sweden - swit zerland - united kingdom ? http://w ww.st.com
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