These 10-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 ten flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are true to the data (D) input.
A buffered output-enable (
) input can be used to place the ten 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
interface or pullup components.
does not affect
the internal operation of the flip-flops. Previously stored data can
be retained or new data can be entered while the outputs are in the
high-impedance state.
The SN54AS821A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74AS821A is characterized for operation from 0°C to 70°C.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | 10-Bit Bus Interface Flip-Flops With 3-State Outputs datasheet (Rev. A) | 01 Aug 1995 | |
| * | SMD | SN54AS821A SMD 5962-90780 | 21 Jun 2016 | |
| Application note | Power-Up Behavior of Clocked Devices (Rev. B) | PDF | HTML | 15 Dec 2022 | |
| Selection guide | Logic Guide (Rev. AB) | 12 Jun 2017 | ||
| Application note | Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) | 02 Dec 2015 | ||
| User guide | LOGIC Pocket Data Book (Rev. B) | 16 Jan 2007 | ||
| Application note | Semiconductor Packing Material Electrostatic Discharge (ESD) Protection | 08 Jul 2004 | ||
| Application note | TI IBIS File Creation, Validation, and Distribution Processes | 29 Aug 2002 | ||
| Application note | Designing With Logic (Rev. C) | 01 Jun 1997 | ||
| Application note | Advanced Schottky Load Management | 01 Feb 1997 | ||
| Application note | Input and Output Characteristics of Digital Integrated Circuits | 01 Oct 1996 | ||
| Application note | Live Insertion | 01 Oct 1996 | ||
| Application note | Advanced Schottky (ALS and AS) Logic Families | 01 Aug 1995 |
For additional terms or required resources, click any title below to view the detail page where available.
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| CDIP (JT) | 24 | Ultra Librarian |
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