HD74HC147

HD74HC147 10-to-4-line Priority Encoder Description The HD74HC147 features priority encoding of the inputs to ensure that only the highest order data line is encoded. Nine input lines are encoded to a four line BCD output. The implied decimal zero codition requires no input condition as zero is encoded when all nine data lines are at a high logic level. All data inputs and outputs are active at the low logic level. Features High Speed Operation: tpd = 14.5 ns typ (CL = 50 pF) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Function Table Inputs 1 H X X X X X X X X L 2 H X X X X X X X L H 3 H X X X X X X L H H 4 H X X X X X L H H H 5 H X X X X L H H H H 6 H X X X L H H H H H 7 H X X L H H H H H H 8 H X L H H H H H H H 9 H L H H H H H H H H Outputs D H L L H H H H H H H C H H H L L L L H H H B H H H L L H H L L H A H L H L H L H L H L HD74HC147 Pin Arrangement 4 1 5 2 Inputs 6 3 7 4 8 5 C 6 Outputs B 7 GND 8 B A 9 6 7 8 C D 3 2 1 5 4 16 VCC 15 NC 14 D 13 3 12 2 Inputs 11 1 10 9 9 A Output Output (Top view) 2 HD74HC147 DC Characteristics Ta = 25°C Item Input voltage Symbol VIH Ta = –40 to +85°C Max — — — 0.5 1.35 1.8 — — — — — 0.1 0.1 0.1 0.33 0.33 ±1.0 40 µA µA I OL = 4 mA I OL = 5.2 mA Vin = VCC or GND Vin = VCC or GND, Iout = 0 µA V I OH = –4 mA I OH = –5.2 mA Vin = VIH or VIL I OL = 20 µA V Vin = VIH or VIL I OH = –20 µA V Unit...