STMicroelectronics 74LVC161284TTR

Overview

74LVC161284TTR from STMicroelectronics is a 48-pin TSSOP IEEE 1284 Level 1/2 bidirectional parallel transceiver with dual-voltage operation (VCC = 3.0–3.6 V, VCC/CABLE = 3.0–5.5 V), 9 ns max propagation delay, 14 mA high-drive sink/source capability on B-port and Y-outputs, and integrated pull-up resistors (1.15–1.65 kΩ) on all open-drain outputs. It enables ECP-mode peripheral interfacing between host logic and printing peripherals.

For engineers reviewing the 74LVC161284TTR datasheet, 74LVC161284TTR pinout, 74LVC161284TTR application, or 74LVC161284TTR equivalent, key selection criteria include direction-controlled bidirectional data flow (DIR), high-drive enable (HD), cable-side 5 V translation support, open-drain vs. totem-pole output mode switching, and compliance with IEEE Std 1284-I/II for legacy parallel port systems.

Technical Context

This transceiver implements two independent signal paths: A-port (host side, 3.3 V logic) connects to B-port/Y-outputs (cable/peripheral side, 5 V tolerant), with DIR controlling data direction (A→B or B→A). HD enables high-drive totem-pole mode on Y9–Y13 and PLO outputs-delivering 84 mA sink at PLO and 14 mA per Y-output-replacing discrete pull-ups and enabling direct 5 V peripheral drive.

The device integrates PMOS backdrive protection on all signal pins to prevent current injection into VCC or VCC/CABLE when those supplies are absent or grounded. Input hysteresis (0.4–0.8 V) ensures noise immunity on control lines (DIR, HD, PLIN), while output skew ≤2 ns guarantees timing coherence across parallel data lanes in ECP handshaking protocols.

Key Specifications

Pinout & Package

74LVC161284TTR is housed in a 48-lead TSSOP package (JEDEC MO-153, body width 6.0–6.2 mm, lead pitch 0.5 mm), optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC161284DGGR and 74ALVC161284TTR, the 74LVC161284TTR uniquely balances TSSOP compactness, integrated pull-ups, and 9 ns timing-making it optimal for cost-sensitive, space-constrained industrial parallel interface modules where BOM simplification and JEDEC-standard packaging are critical.

Availability

74LVC161284TTR is available at Aetrix Electronics and suitable for printer interface modules, industrial parallel adapters, embedded ECP host controllers, and legacy test equipment interfaces requiring stable component supply and long-term obsolescence management.

Supply support for 74LVC161284TTR 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, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The 74LVC logic family targets low-voltage, high-speed applications in battery-powered and energy-efficient systems, with the 74LVC161284 specifically engineered to replace legacy parallel port transceivers while supporting modern 3.3 V host architectures.

FAQ

What is the maximum allowable voltage on VCC/CABLE relative to VCC?

VCC/CABLE must be ≥ VCC and ≤ +7.0 V absolute maximum. Per datasheet Absolute Maximum Ratings, VCC/CABLE may reach up to +7.0 V transiently (40 ns), but recommended operating range is 3.0–5.5 V. Exceeding VCC by more than 0.5 V during steady-state operation risks violating backdrive protection thresholds and may cause latch-up if VCC/CABLE falls below VCC while signals are active.

Can the 74LVC161284TTR operate with VCC = 2.5 V?

No. The device is specified only for VCC = 3.0–3.6 V. At 2.5 V, VIH minimum (2.0 V) and VOH (2.4 V @ −4 mA) fall outside guaranteed operating margins, and internal logic thresholds become unreliable. STMicroelectronics does not characterize or guarantee functionality below 3.0 V; use 74ALVC161284 only if 2.3–3.6 V operation is required.

How does the HD pin affect PLO output behavior?

When HD = HIGH, PLO switches from open-drain to totem-pole mode, enabling ±50 mA drive and −84 mA sink capability. In this state, PLO can actively drive low (0.95 V @ 84 mA) or high (3.15 V @ −500 µA). When HD = LOW, PLO reverts to open-drain with integrated 1.15–1.65 kΩ pull-up, limiting high-state voltage to VCC/CABLE and disabling active high drive.

Are the A14–A17 pins strictly outputs or bidirectional?

A14–A17 (pins 20–23) are unidirectional outputs only-driven from C14–C17 (pins 26–29) under DIR = LOW (B→A mode). Unlike A1–A8, they lack internal feedback paths and cannot be driven by the A-port. Their function is fixed as host-side status/data outputs synchronized to cable-side handshaking signals.