74ACT16821 Datasheet | Texas Instruments

description These 20-bit 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, parity bus interfacing, and working registers. The ’ACT16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. On the positive transition of the clock (CLK) input, the Q outputs follow the data (D) inputs. Each 10-bit flip-flop section has a buffered output-enable (1OE or 2OE) input that can be used to place the ten outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. 54ACT16821 . . . WD PACKAGE 74ACT16821 . . . DL PACKAGE (TOP VIEW) 1OE 1Q1 1Q2 GND 1Q3 1Q4 VCC 1Q5 1Q6 1Q7 GND 1Q8 1Q9 1Q10 2Q1 2Q2 2Q3 GND 2Q4 2Q5 2Q6 VCC 2Q7 2Q8 GND 2Q9 2Q10 2OE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 56 1CLK 55 1D1 54 1D2 53 GND 52 1D3 51 1D4 50 VCC 49 1D5 48 1D6 47 1D7 46 GND 45 1D8 44 1D9 43 1D10 42 2D1 41 2D2 40 2D3 39 GND 38 2D4 37 2D5 36 2D6 35 VCC 34 2D7 33 2D8 32 GND 31 2D9 30 2D10 29 2CLK 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 74ACT16821 is packaged in the TI shrink small-outline package, which provides twice the I/O pin count and functionality of standard small-outline packages in the same printed-circuit-board area. The 54ACT16821 is characterized for operation over the full military temperature range of - 55°C to 125°C. The 74ACT16821 is characterized for operation from - 40°C to 85°C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. EPIC and Widebus are...