74LVC1284D,118

Overview

The 74LVC1284D,118 is a 3.3V parallel printer interface transceiver and buffer designed for asynchronous, 4-bit bi-directional data transmission between personal computers and peripherals. It complies with IEEE 1284 standards (Level 1 & 2) and includes three additional lines for handshaking signals. The device features TTL-compatible inputs with at least 300mV hysteresis at VCC = 3.3V. It operates within a supply voltage range of 3.0V to 3.6V and supports an operating temperature range of 0°C to +70°C. The component is housed in a 20-pin plastic SO package.

Feature Summary

• Provides asynchronous, 4-bit bi-directional parallel printer interface functionality compliant with IEEE 1284 Level 1 and 2 standards.
• Includes three additional buffer/driver lines specifically dedicated to providing handshaking signals between host and peripheral devices.
• Features TTL-compatible inputs with input hysteresis exceeding 300mV at the nominal 3.3V supply voltage.
• Offers overvoltage protection on the B side outputs and ESD protection exceeding 1000V per MIL STD 883 Method 3015.

Applications

• Asynchronous parallel printer interfaces for personal computers
• Bi-directional data transmission between host systems and peripheral devices
• Handshaking signal routing in IEEE 1284 compliant communication links

Procurement Notes

Verify that the ordering code matches the specific package type required, as the 74LVC1284 family is available in multiple configurations including 20-pin plastic SO, SSOP Type II, and TSSOP Type I. Confirm the temperature range aligns with system requirements, noting that the standard D suffix indicates operation from 0°C to +70°C. Ensure compatibility with the target PCB footprint for the selected package variant before procurement.

Selection Notes

Select this component when designing an asynchronous 4-bit parallel interface requiring IEEE 1284 compliance. It is suitable for applications needing TTL-compatible inputs and robust ESD protection. Consider the B-side output drive capabilities and the availability of high-drive enable options if stronger output currents are necessary. Verify that the 3.3V supply voltage range meets the system power architecture constraints.

Part Context

The 74LVC1284 belongs to the LVC logic family, which is optimized for low-voltage operation. This specific part number represents the 20-pin plastic Small Outline (SO) package version. It serves as a specialized interface solution distinct from general-purpose bus drivers by integrating dedicated control lines for printer protocol handshaking directly into the transceiver structure.

Replacement Considerations

Direct pin-to-pin replacements within the same package must maintain IEEE 1284 compliance and 4-bit bidirectional capability. Other variants such as 74LVC1284DB or 74LVC1284PW offer identical electrical functions but utilize different physical packages (SSOP or TSSOP). Cross-package substitution requires verifying mechanical fit and thermal characteristics.

FAQ

What is the maximum input voltage allowed on the A side?

The DC input voltage on the A side can range from -0.5V to VCC + 0.5V.

How does the HD pin affect the B/Y side outputs?

The HD pin enables or disables the high drive mode for the B/Y side outputs, allowing them to operate in either totem pole or open drain style depending on its state.

Is the device compatible with TTL logic levels?

Yes, all inputs are TTL compatible and feature at least 300mV of input hysteresis at VCC = 3.3V.