Diodes Incorporated PI74STX4G4245ZJEX

Overview

PI74STX4G4245ZJEX from Pericom Semiconductor is a 4-bit dual-supply noninverting buffer/transceiver with configurable level-shifting direction control. It features two independent supply rails (VCCA: 1.65–3.6V; VCCB: 2.3–5.5V), unidirectional A1→B1 and bidirectional A2↔B2 channels controlled by the VCCB-supplied xDIR pin, and operates across –40°C to +85°C for industrial interface bridging between 1.8V/3.3V and 2.5V/5V domains.

For engineers reviewing the PI74STX4G4245ZJEX datasheet, PI74STX4G4245ZJEX pinout, PI74STX4G4245ZJEX application, or PI74STX4G4245ZJEX equivalent, key selection criteria include dual-rail voltage tolerance, 5ns typical propagation delay into 30pF, ±24mA B-port drive at 5V, high-impedance power-down mode, and TDFN-16 package compatibility with space-constrained PCB layouts.

Technical Context

This device implements dual-voltage domain translation using separate A- and B-side I/O structures, where xA1/xB1 operate as fixed-direction buffers while xA2/xB2 form a bidirectional channel gated by xDIR referenced to VCCB. The internal logic ensures no bus contention during direction transitions and supports hot-swap capable high-impedance states on power-down.

Electrical isolation between VCCA and VCCB enables robust level shifting without external biasing; input/output voltage ranges extend to VCCx + 0.5V, and absolute maximum ratings support transient overvoltage resilience up to ±50mA diode current. Propagation delay remains stable across VCCA = 1.8V/2.5V/3.3V and VCCB = 2.5V/3.3V/5V combinations.

Key Specifications

Pinout & Package

Package: 16-pin TDFN (ZJ), 3.0mm × 3.0mm, 0.455mm pitch, exposed thermal pad, Pb-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH4T245RGE and TXS0104EPWR, PI74STX4G4245ZJEX uniquely supports 5V B-side operation, includes explicit DIR control for protocol-aligned bidirectional transfers, and offers superior speed and drive capability-making it optimal for industrial and automotive interfaces demanding deterministic timing and wide voltage compatibility.

Availability

PI74STX4G4245ZJEX is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive infotainment head units, and test & measurement equipment requiring stable component supply, long-lifecycle availability, and guaranteed Pb-free/Green compliance.

Supply support for PI74STX4G4245ZJEX 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 provider of high-performance interface, timing, and signal integrity solutions, acquired by Diodes Incorporated in 2016; its portfolio continues under Diodes' Signal Integrity Solutions division.

The PI74STX series targets mixed-voltage system integration, specifically addressing level-shifting challenges in FPGA/CPU-to-peripheral bridges where dual-rail flexibility, low skew, and industrial temperature range are mandatory.

FAQ

Can PI74STX4G4245ZJEX operate with VCCA = 1.8V and VCCB = 5V simultaneously?

Yes. The device is explicitly rated for VCCA = 1.65–3.6V and VCCB = 2.3–5.5V concurrently, with VCCB ≥ VCCA required for proper level translation. At 1.8V/5V, it delivers VOHB ≥ 4.4V and VOLB ≤ 0.55V under 24mA load, meeting 5V TTL thresholds.

What happens to the I/Os during power-down when either VCCA or VCCB is removed?

When either supply is removed or brought below 0.5V, all I/Os enter a high-impedance state with leakage ≤ ±10μA. This prevents back-powering, bus contention, or unintended signal injection into powered domains-critical for hot-swap and partial-power-down systems.

Is the xDIR pin 5V-tolerant when VCCB = 5V?

Yes. xDIR is supplied by VCCB and accepts VIH ≥ 0.7×VCCB and VIL ≤ 0.3×VCCB. At VCCB = 5V, valid logic-high is ≥3.5V and logic-low is ≤1.5V, fully compatible with standard 5V CMOS outputs without external resistive dividers.

Does PI74STX4G4245ZJEX require external pull-up or pull-down resistors on unused pins?

Yes. Per datasheet Note 1, all unused inputs-including xDIR, xA1, and xA2-must be externally tied to VCCA or GND to prevent floating nodes that could cause increased ICC, oscillation, or undefined output states. Unused xB1/xB2 should be left unconnected or terminated per system impedance rules.