The CD74FCT843A is a 9-bit, bus-interface, D-type latch with 3-state outputs, designed specifically for driving highly capacitive or relatively low-impedance loads. It is particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.
The device uses a small-geometry BiCMOS technology. The output stage is a combination of bipolar and CMOS transistors that limits the output high level to two diode drops below VCC. This resultant lowering of output swing (0 V to 3.7 V) reduces power-bus ringing [a source of electromagnetic interference (EMI)] and minimizes VCC bounce and ground bounce and their effects during simultaneous output switching. The output configuration also enhances switching speed and is capable of sinking 48 mA.
The CD74FCT843A outputs are transparent to the inputs when the latch-enable (LE) input is high. The latches are transparent D-type latches. When LE goes low, the data is latched. The output-enable (OE\) input controls the 3-state outputs. When OE\ is high, the outputs are in the high-impedance state. The latch operation is independent of the state of the output enable. This device, having preset (PRE\) and clear (CLR\), are ideal for parity-bus interfacing. When PRE\ is low, the outputs are high if OE\ is low. PRE\ overrides CLR\. When CLR\ is low, the outputs are low if OE\ is low. When CLR\ is high, data can be entered into the latch. The device provides noninverted outputs.
OE\ does not affect the internal operations of the latch. Previously stored data can be retained or new data can be entered while the outputs are in the high-impedance state.
The CD74FCT843A is characterized for operation from 0°C to 70°C.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | BiCMOS 9-Bit Bus-Interface D-Type Latch With 3-State Outputs datasheet | 02 Jul 2000 | |
| 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 | Selecting the Right Level Translation Solution (Rev. A) | 22 Jun 2004 | ||
| Selection guide | Advanced Bus Interface Logic Selection Guide | 09 Jan 2001 |
For additional terms or required resources, click any title below to view the detail page where available.
The 14-24-LOGIC-EVM evaluation module (EVM) is designed to support any logic device that is in a 14-pin to 24-pin D, DW, DB, NS, PW, DYY or DGV package,
| Package | Pins | Download |
|---|---|---|
| SOIC (DW) | 24 | View options |
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.