M74HC242 Datasheet | STMicroelectronics

DESCRIPTION The M54/74HC242/243 are high speed CMOS QUAD BUS TRANSCEIVER (3-STATE) FABRICATED IN SILICON GATE C2MOS technology. They have the same high speed performance of LSTTL bined with true CMOS low power consumption. The HC242/243 are 3 STATE bi-directional inverting and non-inverting buffers and are intended for two-way asynchronous munication between data buses. They are high drive current outputs which enable high speed operation when driving large bus capacitances. Each device has one active high enable (GBA), and one active low enable (GAB). GBA enables the A outputs and GAB enables the B outputs. All inputs are equipped with protection circuits against static discharge and transient excess voltage. INPUT AND OUTPUT EQUIVALENT CIRCUIT ORDER CODES : M54HCXXXF1R M74HCXXXM1R M74HCXXXB1R M74HCXXXC1R PIN CONNECTIONS (top view) HC242 HC243 NC = No Internal Connection October 1993 1/11 M54/M74HC242/243 CHIP CARRIER TRUTH TABLE INPUTS GAB GBA H L H L H L L H FUNCTION A BUS B BUS OUTPUT INPUT OUTPUTS HC242 HC243 A=B A=B B=A Z Z PIN DESCRIPTION PIN No 1 2, 12 3, 4, 5, 6 11, 10, 9, 8 13 7 14 SYMBOL GAB NC 1A to 4A 1B to 4B GBA GND VCC NAME AND FUNCTION Output Enable Input (active LOW) Not connected Data Inputs/Outputs Data Inputs/Outputs Output Enable Input Ground (0V) Positive Supply Voltage INPUT OUTPUT B = A HIGH IMPEDANCE Z HIGH IMPEDANCE Z IEC LOGIC SYMBOLS HC242 HC243 2/11 M54/M74HC242/243 CIRCUIT DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol VCC VI VO IIK IOK IO ICC or IGND PD Tstg TL Supply Voltage DC Input Voltage DC Output Voltage DC Input Diode Current DC Output Diode Current DC Output Source Sink Current Per Output Pin DC VCC or Ground Current Power Dissipation Storage Temperature Lead Temperature (10 sec) Parameter Value -0.5 to +7 -0.5 to VCC + 0.5 -0.5 to VCC + 0.5 ± 20 ± 20 ± 35 ± 70 500 (- ) -65 to +150 300 Unit V V V m A m A m A m A m W o C o Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional...