7 Detailed Description

7.1 Overview

The SNx4ACT244 devices are buffer drivers with separate output enable inputs. The active low output enable

sets the output to high impedance when a logic high is applied. For 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.

7.2 Functional Block Diagram

Figure 7-1. Logic Diagram (Positive Logic)

7.3 Feature Description

The SNx4ACT244 devices are recommended for 4.5 V to 5.5-V VCC range under normal operating conditions.

The inputs are TTL compatible accepting 2-V minimum high at 5-V VCC.

7.4 Device Functional Modes

Table 7-1 lists the functions of the device.

Table 7-1. Function Table (Each Buffer)

INPUTS

OUTPUT

Y

OE

A

L

H

H

L

L

L

H

X

Hi-Z

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SN54ACT244, SN74ACT244

SCAS517G – JUNE 1995 – REVISED MARCH 2024

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Product Folder Links: SN54ACT244 SN74ACT244