20-ch, 4.5-V to 5.5-V buffers with TTL-compatible CMOS inputs and 3-state outputs

The ’ABT162827A devices are noninverting 20-bit buffers composed of two 10-bit buffers with separate output-enable signals. For either 10-bit buffer, the two output-enable (1OE1\ and 1OE2\, or 2OE1\ and 2OE2\) inputs must both be low for the corresponding Y outputs to be active. If either output-enable input is high, the outputs of that 10-bit buffer are in the high-impedance state.

The outputs, which are designed to source or sink up to 12 mA, include equivalent 25- series resistors to reduce overshoot and undershoot.

These devices are fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.

To ensure the high-impedance state during power up or power down, OE\ shall be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.