DESCRIPTION

The M54/74HCT157 and the M54/74HCT158 are high speed CMOS QUAD 2-CHANNEL MULTIPLEXERs fabricated with silicon gate C2MOS technology. They achieve the high speed operation similar to equivalent LSTTL while maintaining the CMOS low power dissipation.

These devices consist of four 2-input digital multiplexers with common select and strobe inputs. The HCT158 is an inverting multiplexer while the HCT157 is a non-inverting multiplexer. When the STROBE input is held High, selection of data is in hibited and all the outputs become Low in the M74HCT157 and High in the M74HCT158. The SELECT decoding determines whether the A or B in puts get routed to their corresponding Y outputs. All inputs are equipped with protection circuits against static discharge and transient excess voltage. M54/74HCT devices are designed to directly interface HSC2MOS systems with TTL and NMOS components. They are also plug in replacements for LSTTL devices giving a reduction of power consumption.

■ HIGH SPEED

tPD = 21 ns (TYP.) AT VCC = 5 V

■ LOW POWER DISSIPATION

ICC = 4 μA (MAX.) AT TA = 25 °C

■ COMPATIBLE WITH TTL OUTPUTS

VIH = 2V (MIN.) VIL = 0.8V (MAX)

■ OUTPUT DRIVE CAPABILITY 10 LSTTL LOADS

■ SYMMETRICAL OUTPUT IMPEDANCE

?IOH? = IOL = 4 mA (MIN.)

■ BALANCED PROPAGATION DELAYS

tPLH = tPHL

■ PIN AND FUNCTION COMPATIBLE

WITH 54/74LS157/158