Diodes Incorporated PI74STX2G4245ZEEX

Overview

PI74STX2G4245ZEEX from Pericom Semiconductor is a 2-bit noninverting level-shifting buffer/transceiver with dual independent supply rails (VDDA: 1.65–3.6V; VDDB: 2.3–5.5V), supporting unidirectional A1→B1 and bidirectional A2↔B2 translation controlled by DIR. It delivers 5ns typical propagation delay into 30pF at 3V, ±12mA drive at 3V VDDA/VDDB, and operates from –40°C to +85°C. Used in mixed-voltage I²C, SMBus, and GPIO interfacing between 1.8V/3.3V logic and 5V peripherals.

For engineers reviewing the PI74STX2G4245ZEEX datasheet, PI74STX2G4245ZEEX pinout, PI74STX2G4245ZEEX application, or PI74STX2G4245ZEEX equivalent, key selection criteria include dual-rail voltage tolerance, DIR-controlled bidirectional capability on A2/B2, guaranteed 5ns max tPLH/tPHL across VDDA/VDDB combinations, industrial temperature support, and TDFN-12 package thermal performance.

Technical Context

The device implements two independent level-shifting paths: A1→B1 is fixed unidirectional, while A2↔B2 direction is actively controlled by the DIR input referenced to VDDB. Both ports support simultaneous operation across non-overlapping voltage domains, enabling seamless interface between sub-1.95V logic (e.g., ARM core I/O) and 5V legacy peripherals.

Internal circuitry includes rail-to-rail input clamping diodes, high-impedance power-down mode (all I/Os tri-stated when disabled), and output drivers rated for ±24mA at 5V VDDB. Propagation delay is characterized down to 1.0ns min and 8ns max depending on VDDA/VDDB pairing and signal direction.

Key Specifications

Pinout & Package

PI74STX2G4245ZEEX is packaged in a Pb-free, RoHS-compliant 12-pin TDFN (Thin Dual Flat No-lead) with 0.5mm pitch, 3mm × 3mm body, and exposed thermal pad for enhanced heat dissipation in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar level-shifting buffer applications.

Compared with TXS0102DCUR and PCA9306DP, PI74STX2G4245ZEEX uniquely supports 5V VDDB operation with ±24mA drive and explicit DIR control-making it the only option among the three qualified for driving 5V TTL loads while maintaining precise direction timing in deterministic systems.

Availability

PI74STX2G4245ZEEX is available at Aetrix Electronics and suitable for industrial automation controllers, embedded computing backplanes, and automotive body control modules requiring stable component supply across extended temperature ranges and dual-voltage interoperability.

Supply support for PI74STX2G4245ZEEX 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 was a fabless analog/mixed-signal IC company specializing in high-speed interface, timing, and signal-integrity solutions before its acquisition by Diodes Incorporated in 2016.

The PI74STX series targets voltage-domain bridging in space-constrained, thermally demanding applications-designed specifically for reliable level shifting in multi-rail embedded systems without external biasing or direction logic.

FAQ

What is the maximum allowable voltage difference between VDDA and VDDB?

VDDA must not exceed VDDB under any operating condition. When VDDA is 1.65V–1.95V, VDDB is limited to ≤3.6V per datasheet note. At higher VDDA (≥2.3V), VDDB may reach 5.5V. This constraint prevents reverse-bias stress on internal ESD structures and ensures correct level translation directionality.

Can the DIR pin be driven from a 1.8V source?

No. The DIR pin is internally referenced to VDDB and requires VIH ≥0.7×VDDB and VIL ≤0.3×VDDB. Driving DIR from 1.8V violates the minimum VIH threshold when VDDB ≥2.5V (e.g., 0.7×2.5V = 1.75V is marginal; 0.7×5V = 3.5V is impossible). DIR must be sourced from the VDDB domain or a compatible level translator.

Is the TDFN-12 package thermally enhanced?

Yes. The PI74STX2G4245ZEEX TDFN-12 includes an exposed thermal pad (pin 5 is GND, but the underside pad is electrically connected to GND and designed for solder attachment to a PCB copper pour). Thermal resistance θJA is reduced by up to 35% versus standard TDFN when the pad is properly soldered and thermally vias are used-critical for sustained ±24mA output operation at +85°C.

Does the device support hot insertion or live swapping between voltage domains?

No. The absolute maximum ratings specify that VDDA and VDDB must be powered within 100ms of each other, and all inputs must be held within –0.5V to VDDx+0.5V before power-up. Applying signal voltage before VDDA/VDDB stabilization risks latch-up or permanent damage due to forward-biased internal diodes-hot insertion requires external sequencing circuitry or dedicated hot-swap ICs.