HD74ALVCH162836

HD74ALVCH162836 20-bit Universal Bus Driver with 3-state Outputs ADE-205-211 (Z) Preliminary 1st. Edition January 1998 Description This 20-bit universal bus driver is designed for 2.3 V to 3.6 V VCC operation. Data flow from A to Y is controlled by the output enable (O E) input. The device operates in the transparent mode when the latch enable (LE) input is low. When LE is high, the A data is latched if the clock (CLK) input is held at a high or low logic level. If LE is high, the A data is stored in the latch flip flop on the low to high transition of CLK. When OE is high, the outputs are in the high impedance state. To ensure the high impedance state during power up or power down, OE should be tied to V CC through a pullup resistor; the minimum value of the resistor is determined by the current sinking capability of the driver. Active bus hold circuitry is provided to hold unused or floating data inputs at a valid logic level. All outputs, which are designed to sink up to 12 mA, include 26 Ω resistors to reduce overshoot and undershoot. Features VCC = 2.3 V to 3.6 V Typical VOL ground bounce < 0.8 V (@VCC = 3.3 V, Ta = 25°C) Typical VOH undershoot > 2.0 V (@VCC = 3.3 V, Ta = 25°C) High output current ±12 mA (@VCC = 3.0 V) Bus hold on data inputs eliminates the need for external pullup / pulldown resistors All outputs have equivalent 26 Ω series resistors, so no external resistors are required. HD74ALVCH162836 Function Table Inputs OE H L L L L L LE X L L H H ...