器件名称:
74HC148
功能描述:
8 TO 3 LINE PRIORITY ENCODER
文件大小:
252.34KB 共11页
简 介:
M54HC148 M74HC148 8 TO 3 LINE PRIORITY ENCODER . . . . . . . . HIGH SPEED tPD = 15 ns (TYP.) AT VCC = 5 V LOW POWER DISSIPATION ICC = 4 A (MAX.) AT TA = 25 °C HIGH NOISE IMMUNITY VNIH = VNIL = 28 % VCC (MIN.) OUTPUT DRIVE CAPABILITY 10 LSTTL LOADS SYMMETRICAL OUTPUT IMPEDANCE IOH = IOL = 4 mA (MIN.) BALANCED PROPAGATION DELAYS tPLH = tPHL WIDE OPERATING VOLTAGE RANGE VCC (OPR) = 2 V TO 6 V PIN AND FUNCTION COMPATIBLE WITH 54/74LS148 B1R (Plastic Package) F1R (Ceramic Package) M1R (Micro Package) C1R (Chip Carrier) ORDER CODES : M54HC148F1R M74HC148M1R M74HC148B1R M74HC148C1R DESCRIPTION The M54/74HC148 is a high speed CMOS 8-TO-3 LINE PRIORITY ENCODER fabricated in silicon gate C2MOS technology. It has the same high speed performance for LSTTL combined with true CMOS low power consumption. The M54/74HC148 encodes eight data lines to three-line (4-2-1) binary (octal). Cascading circuitry (enable input EI and enable output EO) has been provided to allow octal expansion without the need for external circuitry. Data inputs are active at the low logic level. All inputs are equipped with protection circuits against static discharge and transient excess voltage. INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN CONNECTIONS (top view) NC = No Internal Connection October 1992 1/11 M54/M74HC148 TRUTH TABLE INPUTS E1 H L L L L L L L L L X: Don’t Care OUTPUTS 4 X H X X X L H H H H 5 X H X X L H H H H H 6 X H X L H H H H H H 7 X H L H H H H H H H A2 H H L L L L H H H H A1 H H L L H H……
