Diodes Incorporated PI5C3257ZHDEX

Overview

PI5C3257ZHDEX from Diodes Incorporated is a quad 2:1 analog multiplexer/demultiplexer bus switch with three-state outputs, 5Ω on-resistance, 0.25ns propagation delay, and ultra-low quiescent current (0.2µA typical). It operates from 4.5V to 5.5V, supports –40°C to +85°C ambient, and is used in high-speed data routing for notebook and embedded I/O expansion applications.

For engineers reviewing the PI5C3257ZHDEX datasheet, PI5C3257ZHDEX pinout, PI5C3257ZHDEX application, or PI5C3257ZHDEX equivalent, key selection criteria include on-resistance matching, bus enable timing (tPZH/tPLZ ≤ 4.8ns), input hysteresis (150mV), and UQFN-16 thermal performance in space-constrained PCB layouts.

Technical Context

The PI5C3257ZHDEX implements four independent bidirectional 2:1 analog switches controlled by a shared select (S) and enable (E) logic interface. Each switch exhibits near-zero propagation delay due to its low R_ON-C_OFF time constant (~0.25ns for 50pF load), enabling transparent signal pass-through without added jitter or ground bounce.

Its CMOS-compatible control inputs accept TTL/CMOS logic levels (VIH = 2.0V min, VIL = 0.8V max), while the analog path supports rail-to-rail voltage operation (–0.5V to +7.0V) and 120mA output current capability-enabling direct connection to legacy 5V buses without level translation.

Key Specifications

Pinout & Package

PI5C3257ZHDEX is housed in a 16-pin, 3×3 mm UQFN package (ZHD code) with wettable flank leads for automated optical inspection. The package features a center thermal pad connected to GND for enhanced power dissipation in high-density layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2:1 analog switch applications.

Compared with PI74FCT257TQE and SN74CBT3257PW, PI5C3257ZHDEX delivers the lowest on-resistance (5Ω) and quiescent current (0.2µA), making it optimal for thermally constrained, battery-sensitive notebook and embedded applications where signal fidelity and standby power dominate selection criteria.

Availability

PI5C3257ZHDEX is available at Aetrix Electronics and suitable for PCIe lane multiplexing, LPC bus expansion, notebook keyboard/mouse interface, and eSPI host-to-peripheral switching requiring stable component supply and long-term lifecycle assurance.

Supply support for PI5C3257ZHDEX 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and ICs, specializing in high-performance analog, logic, and power management solutions for industrial, computing, and consumer markets.

The PI5C3257 belongs to Diodes' high-speed bus switch product line, designed specifically for low-latency, low-power signal routing in space-constrained computing and embedded platforms where traditional logic-based muxes introduce unacceptable delay or power overhead.

FAQ

What is the maximum capacitive load the PI5C3257ZHDEX can drive while maintaining specified propagation delay?

The device is characterized for CL = 50pF with RL = 500Ω, delivering 0.25ns typical tIY. Driving loads >50pF increases RC delay linearly-e.g., 100pF adds ~0.25ns. For >100pF, add series termination or buffer stages to maintain timing margins in high-speed applications.

Can PI5C3257ZHDEX operate with 3.3V logic control inputs while switching 5V analog signals?

Yes. Control inputs (S, E) meet TTL thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V) at 3.3V, and the analog path supports –0.5V to +7.0V, allowing 3.3V logic to gate 5V signals without level shifters-verified per DC Electrical Characteristics table at VCC = 5V.

Is the thermal pad on the ZHD package electrically connected, and how should it be handled in PCB layout?

Yes, the center thermal pad is internally connected to GND. It must be soldered to a dedicated GND copper pour with ≥4 thermal vias (0.3mm diameter) to inner GND planes. Failure to connect it degrades thermal resistance by >40%, risking junction temperature exceedance above 85°C ambient.

Does PI5C3257ZHDEX support hot-swap or live-insertion on powered buses?

No. While the device tolerates –0.5V to +7.0V on I/Y pins, it lacks built-in hot-swap protection circuitry. Applying signal before VCC stabilization may cause latch-up. Always sequence VCC before analog signals, and use external series resistors or TVS diodes for transient protection in live-insertion scenarios.