Diodes Incorporated PI74LVC4245ALE

Overview

PI74LVC4245ALE from Pericom Semiconductor is an 8-bit non-inverting dual-supply bidirectional bus transceiver with 3-state outputs, enabling asynchronous level translation between 5V (A-port, VCCA = 4.5–5.5V) and 3.3V (B-port, VCCB = 2.7–3.6V) buses. Direction is controlled by DIR; OE enables/disables both ports simultaneously. Used in mixed-voltage system interconnects such as FPGA-to-microcontroller data bridges.

For engineers reviewing the PI74LVC4245ALE datasheet, PI74LVC4245ALE pinout, PI74LVC4245ALE application, or PI74LVC4245ALE equivalent, key selection criteria include dual-rail voltage tolerance, propagation delay ≤6.1 ns (B→A), 3-state isolation timing (tPZL/tPLZ ≤8 ns), and industrial temperature support (–40°C to +85°C).

Technical Context

The PI74LVC4245ALE implements true bidirectional voltage translation via separate A- and B-port power domains, with direction determined solely by the DIR input-no internal arbitration or auto-sensing. Control logic operates referenced to VCCA, ensuring robust timing for 5V-side command signals.

It supports simultaneous high-impedance isolation of both ports when OE is HIGH, eliminating bus contention during power sequencing or state transitions. Propagation delays are asymmetric: tPHL/tPLH from A→B range 5.5–5.7 ns, while B→A are slightly higher at 5.9–6.1 ns under CL = 50 pF conditions.

Key Specifications

Pinout & Package

PI74LVC4245ALE is packaged in a Pb-free, green 24-pin TSSOP (173-mil width, JEDEC MO-153), with 0.65 mm lead pitch and exposed thermal pad option not included. Pin numbering follows standard TSSOP convention (pin 1 marked by dot or bevel).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional level translation applications.

Compared with SN74LVC4245APWR and 74AVC4245PW,118, the PI74LVC4245ALE uniquely supports 5V A-port operation with guaranteed 2.7V minimum VCCB, making it the sole fit for legacy 5V ↔ modern 3.3V industrial backplane interconnects where voltage margins are constrained.

Availability

PI74LVC4245ALE is available at Aetrix Electronics and suitable for industrial PLC backplanes, FPGA I/O expansion bridges, automotive body control modules, and automated test equipment digital I/O cards requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for PI74LVC4245ALE 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-performance interface, timing, and signal-integrity solutions for communications, computing, and industrial markets.

The PI74LVC4245ALE belongs to Pericom's LVC logic family, engineered specifically for robust, low-skew bidirectional voltage translation in mixed-supply embedded systems with stringent ESD and thermal requirements.

FAQ

What is the recommended power-up sequence for PI74LVC4245ALE?

Ground must be connected first. Then apply VCCA (A-port supply) before or concurrently with VCCB (B-port supply). OE should ramp with or ahead of VCCA to prevent bus contention; DIR may be held LOW until VCCA stabilizes, then set per required data direction. This sequence avoids latch-up and ensures predictable 3-state behavior during startup.

Can PI74LVC4245ALE translate between 5V and 1.8V logic levels?

No. The B-port is specified for VCCB = 2.7V to 3.6V only. Applying 1.8V to VCCB violates the absolute maximum rating (VCCB ≥2.7V) and risks undefined output behavior, increased leakage, and potential damage. For 1.8V interfaces, use a dedicated 1.8V-tolerant transceiver such as the SN74LVC4245A with extended VCCB range.

Is the PI74LVC4245ALE pin-compatible with other 24-pin TSSOP bus transceivers?

Yes - the PI74LVC4245ALE shares identical pinout and footprint with industry-standard 24-pin TSSOP 8-bit transceivers including SN74LVC4245APWR and 74LVC4245AD. However, electrical behavior differs: DIR/OE thresholds, propagation delays, and VCCB minima vary, so functional substitution requires validation against system timing and voltage margin requirements.

Does PI74LVC4245ALE require external pull-up or pull-down resistors on A/B ports?

No external biasing is required for normal push-pull operation. However, if either port is left floating during OE = HIGH (3-state), external pull-ups/downs may be needed to prevent indeterminate logic states in downstream receivers. For unused control inputs (DIR, OE), tie to VCCA or GND per recommended operating conditions - never leave floating.