HD74ALVCH162831

Notes: Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute maximum rated conditions for extended periods may affect device reliability.
1. The input and output negative voltage ratings may be exceeded if the input and output clamp current ratings are observed.
2. This value is limited to 4.6 V maximum.
3. The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 750 mils.

This HD74ALVCH162831 1-bit to 4-bit address register / driver is designed for 2.3 V to 3.6 V VCC operation. The device is ideal for use in applications in which a single address bus is driving four separate memory locations. The HD74ALVCH162831 can be used as a buffer or a register, depending on the logic level of the select (SEL) input. When SEL is logic high, the device is in the buffer mode. The outputs follow the inputs and are controlled by the two output enable (OE) controls. Each OE controls two groups of nine outputs. When SEL is logic low, the device is in the register mode. The register is an edge triggered D-type flip flop. On the positive transition of the clock (CLK) input, data set up at the A inputs is stored in the internal registers. OE controls operate the same as in buffer mode. When OE is logic low, the outputs are in a normal logic state (high or low logic level). When OE is logic 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 VCC through a pullup registor; the minimum value of the registor is determined by the current sinking capability of the driver. SEL and OE do not affect the internal operation of the flip flops. Old data can be retained or new data can be entered while the outputs are in the high impedance state. Active bus hold circuitry is provided to hold unused or floating data inputs at a valid logic level. All outputs of HD74ALVCH162831 are designed to sink up to 12 mA, include 26 resistors to reduce overshoot and undershoot.