d a t a sh eet product speci?cation file under integrated circuits, ic06 september 1993 integrated circuits 74hc/hct245 octal bus transceiver; 3-state for a complete data sheet, please also download: the ic06 74hc/hct/hcu/hcmos logic family specifications the ic06 74hc/hct/hcu/hcmos logic package information the ic06 74hc/hct/hcu/hcmos logic package outlines
september 1993 2 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 features octal bidirectional bus interface non-inverting 3-state outputs output capability: bus driver i cc category: msi general descriptions the 74hc/hct245 are high-speed si-gate cmos devices and are pin compatible with low power schottky ttl (lsttl). they are specified in compliance with jedec standard no. 7a. the 74hc/hct245 are octal transceivers featuring non-inverting 3-state bus compatible outputs in both send and receive directions. the 245 features an output enable ( oe) input for easy cascading and a send/receive (dir) for direction control. oe controls the outputs so that the buses are effectively isolated. the 245 is similar to the 640 but has true (non-inverting) outputs. quick reference data gnd = 0 v; t amb =25 c; t r =t f = 6 ns notes 1. c pd is used to determine the dynamic power dissipation (p d in m w): p d =c pd v cc 2 f i +? (c l v cc 2 f o ) where: f i = input frequency in mhz f o = output frequency in mhz ? (c l v cc 2 f o ) = sum of outputs c l = output load capacitance in pf v cc = supply voltage in v 2. for hc the condition is v i = gnd to v cc for hct the condition is v i = gnd to v cc - 1.5 v ordering information see 74hc/hct/hcu/hcmos logic package information . symbol parameter conditions typical unit hc hct t phl / t plh propagation delay a n to b n ;b n to a n c l = 15 pf; v cc =5v 7 10 ns c i input capacitance 3.5 3.5 pf c i / o input/output capacitance 10 10 pf c pd power dissipation capacitance per transceiver notes 1 and 2 30 30 pf
september 1993 3 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 pin description pin no. symbol name and function 1 dir direction control 2, 3, 4, 5, 6, 7, 8, 9 a 0 to a 7 data inputs/outputs 10 gnd ground (0 v) 18, 17, 16, 15, 14, 13, 12, 11 b 0 to b 7 data inputs/outputs 19 oe output enable input (active low) 20 v cc positive supply voltage fig.1 pin configuration. fig.2 logic symbol. fig.3 iec logic symbol.
september 1993 4 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 fig.4 functional diagram. function table notes 1. h = high voltage level l = low voltage level x = dont care z = high impedance off-state inputs inputs/outputs oe dir a n b n l l h l h x a=b inputs z inputs b=a z
september 1993 5 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 dc characteristics for 74hc for the dc characteristics see 74hc/hct/hcu/hcmos logic family specifications . output capability: bus driver i cc category: msi ac characteristics for 74hc gnd = 0 v; t r =t f = 6 ns; c l =50pf symbol parameter t amb ( c) unit test conditions 74hc v cc (v) waveforms + 25 - 40 to + 85 - 40 to + 125 min. typ. max. min. max. min. max. t phl / t plh propagation delay a n to b n; b n to a n 25 9 7 90 18 15 115 23 20 135 27 23 ns 2.0 4.5 6.0 fig.5 t pzh / t pzl 3-state output enable time oe to a n; oe to b n signalname dir 30 11 9 150 30 26 190 38 33 225 45 38 ns 2.0 4.5 6.0 fig.6 t phz / t plz 3-state output disable time oe to a n; oe to b n signalname dir 41 15 12 150 30 26 190 38 33 225 45 38 ns 2.0 4.5 6.0 fig.6 t thl / t tlh output transition time 14 5 4 60 12 10 75 15 13 90 18 15 ns 2.0 4.5 6.0 fig.5
september 1993 6 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 dc characteristics for 74hct for the dc characteristics see 74hc/hct/hcu/hcmos logic family specifications . output capability: bus driver i cc category: msi note to hct types the value of additional quiescent supply current ( d i cc ) for a unit load of 1 is given in the family specifications. to determine d i cc per input, multiply this value by the unit load coefficient shown in the table below. ac characteristics for 74hct gnd = 0 v; t r =t f = 6 ns; c l =50pf input unit load coefficient a n b n oe dir 0.40 0.40 1.50 0.90 symbol parameter t amb ( c) unit test conditions 74hct v cc (v) waveforms + 25 - 40 to + 85 - 40 to + 125 min. typ. max. min. max. min. max. t phl / t plh propagation delay a n to b n; b n to a n 12 22 28 33 ns 4.5 fig.5 t pzh / t pzl 3-state output enable time oe to a n; oe to b n signalname dir 16 30 38 45 ns 4.5 fig.6 t phz / t plz 3-state output disable time oe to a n; oe to b n signalname dir 16 30 38 45 ns 4.5 fig.6 t thl / t tlh output transition time 5 12 15 18 ns 4.5 fig.5
september 1993 7 philips semiconductors product speci?cation octal bus transceiver; 3-state 74hc/hct245 ac waveforms package outlines see 74hc/hct/hcu/hcmos logic package outlines . fig.5 waveforms showing the input (a n , b n ) to output (b n , a n ) propagation delays and the output transition times. (1) hc : v m = 50%; v i = gnd to v cc . hct : v m = 1.3 v; v i = gnd to 3 v. fig.6 waveforms showing the 3-state enable and disable times. (1) hc : v m = 50%; v i = gnd to v cc . hct : v m = 1.3 v; v i = gnd to 3 v.
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