SN74ABT16821 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, bidirectional bus drivers with parity, and working registers. The ’ABT16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The 20 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. SN54ABT16821 . . . WD PACKAGE SN74ABT16821 . . . DGG OR DL PACKAGE (TOP VIEW) 1OE 1 1Q1 2 1Q2 3 GND 4 1Q3 5 1Q4 6 VCC 7 1Q5 8 1Q6 9 1Q7 10 GND 11 1Q8 12 1Q9 13 1Q10 14 2Q1 15 2Q2 16 2Q3 17 GND 18 2Q4 19 2Q5 20 2Q6 21 VCC 22 2Q7 23 2Q8 24 GND 25 2Q9 26 2Q10 27 2OE 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 A buffered output-enable (OE) input can be used to place the ten outputs in either a normal logic state (high or low logic 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 ponents. 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. The SN54ABT16821 is characterized for operation over the full military temperature range of - 55°C to 125°C. The SN74ABT16821 is characterized for operation from - 40°C to 85°C. Please be aware that an important notice concerning...