SN74ALVCH16823
18-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS

SCES038A - JULY 1995 - REVISED NOVEMBER 1996

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

features

• Member of the Texas Instruments Widebus ^TM Family
• EPIC^TM (Enhanced-Performance Implanted CMOS) Submicron Process
• ESD Protection Exceeds 2000 V Per MIL-STD-883, Method 3015; Exceeds 200 V Using Machine Model (C = 200 pF, R = 0)
• Latch-Up Performance Exceeds 250 mA Per JEDEC Standard JESD-17
• Bus Hold on Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors
• Package Options Include Plastic 300-mil Shrink Small-Outline (DL) and Thin Shrink Small-Outline (DGG) Packages

  EPIC and Widebus are trademarks of Texas Instruments Incorporated.

description

This 18-bit bus-interface flip-flop is designed for 2.3-V to 3.6-V V_CC operation.

The SN74ALVCH16823 features 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. This device is particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.

The SN74ALVCH16823 can be used as two 9-bit flip-flops or one 18-bit flip-flop. With the clock-enable () input low, the D-type flip-flops enter data on the low-to-high transitions of the clock. Taking high disables the clock buffer, thus latching the outputs. Taking the clear () input low causes the Q outputs to go low independently of the clock.

A buffered output-enable () input can be used to place the nine outputs in either a normal logic state (high or low logic levels) 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 need for interface or pullup components.

The output-enable () input 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.

To ensure the high-impedance state during power up or power down, 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.

The SN74ALVCH16823 is available in TI's shrink small-outline (DL) and thin shrink small-outline (DGG) packages, which provide twice the I/O pin count and functionality of standard small-outline packages in the same printed circuit board area.

The SN74ALVCH16823 is characterized for operation from -40°C to 85°C.