HD74HC251 Datasheet | Hitachi Semiconductor

Description This multiplexer features both true (Y) and plement (W) outputs as well as a strobe input. The strobe must be at a low logic level to enable this device. When the strobe input is high, both outputs are in the high impedance state. When enabled, address information on the data select inputs determines which data input is routed to the Y and W outputs. Features - - - - - High Speed Operation: tpd (A, B, C to Y) = 20 ns typ (C L = 50 p F) 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 Select C X L L L L H H H H B X L L H H L L H H A X L H L H L H L H Strobe S H L L L L L L L L Outputs Y Z D0 D1 D2 D3 D4 D5 D6 D7 W Z D0 D1 D2 D3 D4 D5 D6 D7 Notes 1. H: high level, L: low level, X: irrelevant 2. Z; high impedcance (off-state) 3. D0 through D7; the level of the respective D input. Pin Arrangement 3 2 Data inputs 1 0 Y Outputs W Strobe GND 1 2 3 4 5 6 7 8 D2 D1 D0 Y W S C D3 D4 D5 D6 D7 A B 16 VCC 15 4 14 5 Data inputs 13 6 12 7 11 A 10 B 9 C Data select (Top view) Block Diagram D0 D1 D2 Strobe D3 D4 D5 VCC D6 W D7 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 ±5.0 ±1.0 40 µA µA µA I OL = 4 m A I OL = 5.2 m A Vin = VIH or VIL, Vout = VCC or GND Vin = VCC or GND Vin = VCC or GND, Iout = 0 µA V I OH = - 4 m A I OH = - 5.2 m A Vin = VIH or VIL I OL = 20 µA V Vin = VIH or VIL I OH = - 20 µA V Unit V Test Conditions VCC (V) Min Typ Max Min 2.0 4.5 6.0 1.5 - 3.15 - 4.2 - - - -...