STMicroelectronics 74LVCZ161284ATTR

Overview

74LVCZ161284ATTR from STMicroelectronics is a low-voltage, high-speed IEEE 1284-compliant bidirectional parallel transceiver with auto power-up logic, 3.0–3.6 V operation, 9 ns max propagation delay (B→A), and integrated pull-up resistors on all open-drain outputs-designed for ECP-mode printer interface between PC host and peripheral devices.

For engineers reviewing the 74LVCZ161284ATTR datasheet, 74LVCZ161284ATTR pinout, 74LVCZ161284ATTR application, or 74LVCZ161284ATTR equivalent, key selection criteria include direction-controlled bidirectional data flow (DIR), high-drive totem-pole capability (14 mA sink/source on B/Y ports), error-free power-up behavior, IEEE 1284 Level 1/2 compliance, and 3.3 V–5 V translation support across cable-side signals.

Technical Context

This device implements dual-port buffering with eight A↔B bidirectional buffers (A1–A8 ↔ B1–B8), five A→Y unidirectional buffers (A9–A13 → Y9–Y13), and four C↔A control-path buffers (C14–C17 ↔ A14–A17), plus dedicated PLI/PLO and HLI/HLO logic paths-all operating under IEEE 1284 signaling protocol timing constraints.

The HD input enables high-drive totem-pole mode (14 mA) on B/Y outputs, while DIR controls directionality; an active-input detection circuit holds Y9–Y13 high at power-up until any of A9–A13 transitions high, preventing spurious BUSY deassertion in printer systems.

Key Specifications

Pinout & Package

Package: TSSOP-48 (4.4 mm × 12.5 mm body, 0.5 mm pitch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar IEEE 1284 transceiver applications.

Compared with 74LVCZ161284ATTR, the 74LVC1284ADTR lacks integrated pull-ups and power-up safety logic-increasing BOM and risk of printer errors-while SN74LVC161284DGGR offers drop-in compatibility with a 1 ns timing penalty requiring design margin verification.

Availability

74LVCZ161284ATTR is available at Aetrix Electronics and suitable for printer interface modules, industrial ECP adapters, and embedded diagnostic port implementations requiring stable component supply, long-term lifecycle support, and guaranteed IEEE 1284 compliance.

Supply support for 74LVCZ161284ATTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer applications.

The 74LVCZ series targets low-voltage, high-speed interface solutions for legacy protocol bridging-specifically engineered to replace obsolete 5 V TTL transceivers while maintaining backward compatibility and reducing system power.

FAQ

What is the purpose of the HD pin?

The HD (High Drive) pin enables totem-pole output mode on B-port and Y-port drivers, allowing ±14 mA drive capability instead of open-drain operation. When HD is HIGH, these outputs actively drive high/low states-critical for driving heavy capacitive loads on long parallel cables without external buffers.

Does this device support 5 V logic on the cable side?

Yes-the B1–B8 and Y9–Y13 pins are 5 V-tolerant with VIH up to 5.5 V and VOH specified at 2.0 V (IO = –14 mA) when VCCcable = 4.5 V. This allows direct interfacing with legacy 5 V printer peripherals without external level translators.

How does the auto power-up feature prevent printer errors?

At power-on, Y9–Y13 outputs are held HIGH until any of A9–A13 transitions HIGH. This prevents premature deassertion of the BUSY signal-a common cause of "printer not ready" errors-by ensuring the peripheral sees valid handshake states before host software begins communication.

Can the DIR and HD pins be tied together?

No-DIR controls data direction (A↔B), while HD controls output drive strength (open-drain vs totem-pole) on B/Y ports. Tying them would force simultaneous direction and drive mode changes, violating IEEE 1284 timing and risking bus contention or incorrect status reporting during handshaking sequences.