SN74ALVC16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS

SCAS269 - MARCH 1993 - REVISED MARCH 1994

features

• Member of the Texas Instruments Widebus^TM Family
• EPIC^TM (Enhanced-Performance Implanted CMOS) Submicron Process
• Supports Unregulated Battery Operation Down to 2.7 V
• Typical V_OLP (Output Ground Bounce) 0.8 V at V_CC = 3.3 V, T_A = 25°C
• Typical V_OHV (Output V_OH Undershoot) > 2 V at V_CC = 3.3 V, T_A = 25°C
• 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 20-bit bus-interface flip-flop is designed specifically for low-voltage (3.3 V) V_CC operation.

The SN74ALVC16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The twenty flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the device provides true data at the Q outputs.

A buffered output-enable () input can be used to place the ten 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 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.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.

The SN74ALVC16821 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 SN74ALVC16821 is characterized for operation from -40°C to 85°C.