These 18-bit bus-interface flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
The ABT162823A devices can be used as two 9-bit flip-flops or one 18-bit flip-flop. With the clock-enable (CLKEN)\ input low, the D-type flip-flops enter data on the low-to-high transitions of the clock. Taking CLKEN\ high disables the clock buffer, thus latching the outputs. Taking the clear (CLR)\ input low causes the Q outputs to go low independently of the clock.
A buffered output-enable (OE)\ input places the nine outputs in either a normal logic state (high or low level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without interface or pullup components. OE\ does 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.
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.
Products containing the "SN74ABT162823A" keyword are: SN74ABT162823ADL , SN74ABT162823ADL , SN74ABT162823ADLR , SN74ABT162823ADLRWidebus is a trademark of Texas Instruments.
Status | ACTIVE |
SubFamily | D-type flip-flop |
Technology Family | ABT |
VCC | 5.5 |
Bits | 18 |
Voltage | 5 |
F @ nom voltage | 150 |
ICC @ nom voltage | 80 |
tpd @ Nom Voltage | 7.5 |
3-state output | Yes |
Rating | Catalog |
Operating temperature range | -40 to 85 |
Package Group | SSOP|56 |
Package size: mm2:W x L (PKG) | [pf]56SSOP[/pf]: 191 mm2: 10.35 x 18.42 (SSOP|56) |
Approx. price | 1.53 | 1ku |