74LVCH244AD,118

Overview

The Nexperia 74LVCH244AD,118 is an octal buffer and line driver featuring three-state outputs. It operates within a supply voltage range of 1.2 V to 3.6 V and supports input voltages up to 5.5 V. The device includes IOFF circuitry for partial power-down mode operation and bus hold functionality on all data inputs. It complies with JEDEC standards JESD8-7A, JESD8-5A, and JESD8-C/JESD36. The component is specified for ambient temperatures from -40 °C to +125 °C and utilizes the SO20 plastic small outline package (SOT163-1).

Feature Summary

• Features two independent output enables controlling four 3-state outputs each.
• Includes IOFF circuitry to prevent damaging backflow current during partial power-down.
• Provides bus hold capability on all data inputs to maintain stable logic states.
• Inputs are overvoltage tolerant up to 5.5 V, enabling direct interface with TTL levels.

Applications

• Mixed 3.3 V and 5 V voltage translation environments
• Partial power-down applications requiring IOFF protection
• Bus holding in high-noise or floating input scenarios

Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the 74LVCH244A series is available in multiple configurations including TSSOP and QFN variants. Confirm the temperature grade corresponds to the operational requirements, noting that the AD suffix indicates the -40 °C to +125 °C range. Ensure compatibility with JEDEC standards relevant to the target application environment before finalizing procurement.

Selection Notes

Select this component when designing systems requiring octal buffering with independent control over output states. The inclusion of bus hold features makes it suitable for noisy environments where input stability is critical. Verify that the 5.5 V input tolerance aligns with the driving source voltages. Consider the thermal dissipation characteristics if operating near the upper limits of the recommended temperature range.

Part Context

This part belongs to the 74LVC/LVCH244A family of octal buffers and line drivers. The 'H' designation specifically denotes the addition of bus hold circuitry on the data inputs compared to the standard 74LVC244A variant. Both devices share identical electrical characteristics regarding speed, drive strength, and power consumption, differing primarily in input state retention capabilities.

Replacement Considerations

The 74LVC244AD,118 serves as a functional substitute for the 74LVCH244AD,118, provided that bus hold functionality is not required by the design. Designers must verify that the absence of bus hold circuits in the LVC variant does not compromise signal integrity in the specific application context.

FAQ

Does the 74LVCH244AD include bus hold circuitry?

Yes, the 74LVCH244A variant includes bus hold circuitry on all data inputs, which maintains the input state even when the driving signal is removed or floats.

How does the IOFF circuitry function?

The IOFF circuitry disables the outputs when the device is powered down, preventing potentially damaging backflow current through the device when VCC is 0 V but inputs or outputs are at 5.5 V.

What is the maximum input voltage supported?

The inputs are overvoltage tolerant and can accept voltages up to 5.5 V, allowing direct interfacing with 5 V devices even when the supply voltage is lower.