1/10 september 2001 n 5v tolerant inputs and outputs n high speed : t pd = 7.0 ns (max.) at v cc = 3v n power down protection on inputs and outputs n symmetrical output impedance: |i oh | = i ol = 24ma (min) at v cc = 3v n pci bus levels guaranteed at 24 ma n balanced propagation delays: t plh @ t phl n operating voltage range: v cc (opr) = 2.0v to 3.6v (1.5v data retention) n pin and function compatible with 74 series 245 n latch-up performance exceeds 500ma (jesd 17) n esd performance: hbm > 2000v (mil std 883 method 3015); mm > 200v description the 74lcx245 is a low voltage cmos octal bus transceiver (3-state) fabricated with sub-micron silicon gate and double-layer metal wiring c 2 mos technology. it is ideal for low power and high speed 3.3v applications; it can be interfaced to 5v signal environment for both inputs and outputs. it has same speed performance at 3.3v than 5v ac/act family, combined with a lower power consumption. this ic is intended for two way asynchronous communication between data buses; 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 and outputs are equipped with protection circuits against static discharge, giving them 2kv esd immunity and transient excess voltage. all floating bus terminals during high z state must be held high or low. 74lcx245 low voltage cmos octal bus transceiver(3-state) with 5v tolerat inputs and outputs pin connection and iec logic symbols order codes package tube t & r sop 74lcx245m 74lcx245mtr tssop 74LCX245TTR tssop sop
74lcx245 2/10 input and output equivalent circuit pin description truth table x : dont care z : high impedance 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 l l output input a = b l h input output b = a hxzzz
74lcx245 3/10 absolute maximum ratings absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditi ons is not implied 1) i o absolute maximum rating must be observed 2) v o < gnd recommended operating conditions 1) truth table guaranteed: 1.5v to 3.6v 2) v in from 0.8v to 2v at v cc = 3.0v symbol parameter value unit v cc supply voltage -0.5 to +7.0 v v i dc input voltage -0.5 to +7.0 v v o dc output voltage (off state) -0.5 to +7.0 v v o dc output voltage (high or low state) (note 1) -0.5 to v cc + 0.5 v i ik dc input diode current - 50 ma i ok dc output diode current (note 2) - 50 ma i o dc output current 50 ma i cc dc supply current per supply pin 100 ma i gnd dc ground current per supply pin 100 ma t stg storage temperature -65 to +150 c t l lead temperature (10 sec) 300 c symbol parameter value unit v cc supply voltage (note 1) 2.0 to 3.6 v v i input voltage 0 to 5.5 v v o output voltage (off state) 0 to 5.5 v v o output voltage (high or low state) 0 to v cc v i oh , i ol high or low level output current (v cc = 3.0 to 3.6v) 24 ma i oh , i ol high or low level output current (v cc = 2.7v) 12 ma t op operating temperature -55 to 125 c dt/dv input rise and fall time (note 2) 0 to 10 ns/v
74lcx245 4/10 dc specifications dynamic switching characteristics 1) number of outputs defined as "n". measured with "n-1" outputs switching from high to low or low to high. the remaining outpu t is measured in the low state. symbol parameter test condition value unit v cc (v) -40 to 85 c -55 to 125 c min. max. min. max. v ih high level input voltage 2.7 to 3.6 2.0 2.0 v v il low level input voltage 0.8 0.8 v v oh high level output voltage 2.7 to 3.6 i o =-100 m av cc -0.2 v cc -0.2 v 2.7 i o =-12 ma 2.2 2.2 3.0 i o =-18 ma 2.4 2.4 i o =-24 ma 2.2 2.2 v ol low level output voltage 2.7 to 3.6 i o =100 m a 0.2 0.2 v 2.7 i o =12 ma 0.4 0.4 3.0 i o =16 ma 0.4 0.4 i o =24 ma 0.55 0.55 i i input leakage current 2.7 to 3.6 v i = 0 to 5.5v 5 5 m a i off power off leakage current 0 v i or v o = 5.5v 10 10 m a i oz high impedance output leakage current 2.7 to 3.6 v i = v ih or v il v o = 0 to v cc 5 5 m a i cc quiescent supply current 2.7 to 3.6 v i = v cc or gnd 10 10 m a v i or v o = 3.6 to 5.5v 10 10 d i cc i cc incr. per input 2.7 to 3.6 v ih = v cc - 0.6v 500 500 m a symbol parameter test condition value unit v cc (v) t a = 25 c min. typ. max. v olp dynamic low level quiet output (note 1) 3.3 c l = 50pf v il = 0v, v ih = 3.3v 0.8 v v olv -0.8
74lcx245 5/10 ac electrical characteristics 1) skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switch- ing in the same direction, either high or low (t oslh = | t plhm - t plhn |, t oshl = | t phlm - t phln |) 2) parameter guaranteed by design capacitive characteristics 1) c pd is defined as the value of the ics 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 x v cc x f in + i cc /8 (per circuit) symbol parameter test condition value unit v cc (v) c l (pf) r l ( w ) t s = t r (ns) -40 to 85 c -55 to 125 c min. max. min. max. t plh t phl propagation delay time 2.7 50 500 2.5 1.5 8.0 1.5 9.2 ns 3.0 to 3.6 1.5 7.0 1.5 8.1 t pzl t pzh output enable time 2.7 50 500 2.5 1.5 9.5 1.5 10.7 ns 3.0 to 3.6 1.5 8.5 1.5 9.7 t plz t phz output disable time 2.7 50 500 2.5 1.5 8.5 1.5 9.7 ns 3.0 to 3.6 1.5 7.5 1.5 8.7 t oslh t oshl output to output skew time (note1, 2) 3.0 to 3.6 50 500 2.5 1.0 1.0 ns symbol parameter test condition value unit v cc (v) t a = 25 c min. typ. max. c in input capacitance 3.3 v in = 0 to v cc 6pf c out output capacitance 3.3 v in = 0 to v cc 12 pf c pd power dissipation capacitance (note 1) 3.3 f in = 10mhz v in = 0 or v cc 45 pf
74lcx245 6/10 test circuit c l = 50 pf or equivalent (includes jig and probe capacitance) r l = r1 = 500 w or equivalent r t = z out of pulse generator (typically 50 w ) waveform 1 : propagation delays (f=1mhz; 50% duty cycle) test switch t plh , t phl open t pzl , t plz 6v t pzh , t phz gnd
74lcx245 7/10 waveform 2: output enable and disable time (f=1mhz; 50% duty cycle)
74lcx245 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
74lcx245 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 80 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
74lcx245 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 infringement of patents or other rights of third parties which may result f rom its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specificati ons mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of stmicroelectronics. ? the st logo is a registered trademark of stmicroelectronics ? 2000 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 - switzerland - united kingdom ? http://www.st.com
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