SN74BCT29844
9-BIT BUS-INTERFACE D-TYPE LATCH
WITH 3-STATE OUTPUTS

SCBS077A - SEPTEMBER 1991 - REVISED NOVEMBER 1993

features

• State-of-the-Art BiCMOS Design Significantly Reduces I_CCZ
• ESD Protection Exceeds 2000 V Per MIL-STD-883C, Method 3015; Exceeds 200 V Using Machine Model (C = 200 pF, R = 0)
• Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic 300-mil DIPs (NT)

description

The SN74BCT29844 features 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. It is particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.

The nine latches are transparent D-type latches. When the latch-enable (LE) input is high, the Q outputs are complementary to the inverting data (D\) inputs.

A buffered output-enable () input can be used to place the nine outputs in either a normal logic state (high or low 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 pull-up components.

The output enable () 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 SN74BCT29844 is characterized for operation from 0°C to 70°C.