74HCT244D,653

Overview

The Nexperia 74HCT244D,653 is an octal buffer and line driver featuring non-inverting 3-state outputs. It operates within a supply voltage range of 4.5 V to 5.5 V and utilizes the HCT logic family for TTL-compatible input levels. The device provides two independent output enable inputs (1OE and 2OE), each controlling four outputs. It is housed in a SO20 plastic small outline package (SOT163-1) with a body width of 7.5 mm. The component supports an operating temperature range from -40 °C to +125 °C.

Feature Summary

• Features two independent output enables (1OE and 2OE) that control four 3-state outputs each, allowing flexible bus interface configurations.
• Includes clamp diodes on all inputs, enabling the use of current limiting resistors to interface inputs to voltages exceeding VCC.
• Provides high noise immunity and low power dissipation characteristics typical of CMOS technology.
• Offers ESD protection meeting ANSI/ESDA/JEDEC JS-001 class 2 standards for Human Body Model and JS-002 class C3 for Charged Device Model.

Applications

• Octal bus interface systems
• Mixed voltage environments requiring level translation
• General-purpose buffering and line driving

Procurement Notes

Verify the specific ordering suffix

Selection Notes

Select this component when designing circuits requiring an 8-bit buffer with tri-state capability and TTL-compatible inputs. Ensure the design accommodates the specified 4.5 V to 5.5 V supply voltage range and the thermal requirements for the SO20 package across the industrial temperature range.

Part Context

This part belongs to the 74HCT series of logic integrated circuits manufactured by Nexperia. The 'D' designation indicates the SO20 surface-mount package variant, while ',653' identifies the specific tape-and-reel packaging configuration. It is functionally compatible with other standard 74HCT244 devices adhering to JEDEC standards.

Replacement Considerations

Check for equivalent parts such as the 74HC244D if CMOS input levels are acceptable, or variants from other manufacturers like SN74HCT244. Verify pinout compatibility and ensure the replacement meets the same electrical specifications and package dimensions.

FAQ

How does the 74HCT244D handle input voltages higher than VCC?

The device includes clamp diodes on its inputs. This feature allows the use of current-limiting resistors to safely interface inputs to voltages exceeding the supply voltage (VCC).

What is the function of the 1OE and 2OE pins?

These are active-low output enable inputs. A HIGH level on either pin causes the corresponding four outputs to assume a high-impedance OFF-state, effectively disconnecting them from the bus.