This 20-bit flip-flop is designed specifically for 1.65-V to 3.6-V VCC operation.

The 20 flip-flops of the SN74ALVCH16721 are edge-triggered D-type flip-flops with qualified clock storage. On the positive transition of the clock (CLK) input, the device provides true data at the Q outputs if the clock-enable (CLKEN)\ input is low. If CLKEN\ is high, no data is stored.

A buffered output-enable (OE)\ input places the 20 outputs in either a normal logic state (high or low) or the 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. 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.

To ensure the high-impedance state during power up or power down, OE\ should be tied to VCC 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 SN74ALVCH16721 is characterized for operation from –40°C to 85°C.

• Member of the Texas Instruments Widebus™ Family
• EPIC™ (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 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), Thin Shrink Small-Outline (DGG), and Thin Very Small-Outline (DGV) Packages

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