Diodes Incorporated PI3B3257Q

Overview

PI3B3257Q from Diodes Incorporated is a 3.3 V quad 2:1 multiplexer/demultiplexer with three-state outputs, pinout- and function-compatible with 74F257 and 74ALS/AS/LS257 logic families. It features 5 Ω switch on-resistance, 4.8 ns max propagation delay, and 0.1 µA typical quiescent current, enabling low-noise signal routing in notebook and portable computing applications.

For engineers reviewing the PI3B3257Q datasheet, PI3B3257Q pinout, PI3B3257Q application, or PI3B3257Q equivalent, key selection criteria include its rail-to-rail logic input tolerance (0–3.6 V), ultra-low power consumption, QSOP-16 package compatibility, and absence of ground bounce during switching.

Technical Context

The PI3B3257Q implements four independent analog/digital bus switches controlled by a shared select (S) and enable (E) input. Each switch operates as a bidirectional, low-impedance path between one of two inputs (IA0/IA1, IB0/IB1, etc.) and its corresponding output (YA–YD), with no internal logic buffering-only passive FET-based transmission gates.

Its operation requires VCC = 3.3 V ±10%, supports –40°C to +85°C ambient operation, and tolerates input voltages up to 3.6 V regardless of supply level. The device draws only 0.1 µA ICC in quiescent state and exhibits near-zero intrinsic propagation delay dominated solely by RC time constant of 5 Ω RON and load capacitance.

Key Specifications

Pinout & Package

PI3B3257Q is supplied in a 16-pin QSOP (150-mil width) package with exposed thermal pad not present-unlike the ZHD variant. Pin 1 is marked via notch or bevel; GND (Pin 12) and VCC (Pin 11) are adjacent for local decoupling. All I/O pins are bidirectional and electrically symmetrical.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVC257PW and SN74CBT3257PWR, the PI3B3257Q delivers superior signal fidelity (5 Ω vs. ≥7 Ω), broader input voltage margin (0–3.6 V), and lower static power (0.1 µA), making it optimal for portable, mixed-signal, and thermally constrained applications.

Availability

PI3B3257Q is available at Aetrix Electronics and suitable for high-speed notebook data routing, PCIe lane multiplexing, and industrial PLC I/O expansion requiring stable component supply and long-lifecycle availability.

Supply support for PI3B3257Q 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 integrated circuits, specializing in high-performance, energy-efficient solutions for consumer, computing, industrial, and communications markets.

The PI3B3257 belongs to Diodes' NanoSwitch™ bus switch product line, engineered for ultra-low on-resistance and near-zero propagation delay in portable and high-density signal routing applications.

FAQ

Can PI3B3257Q operate with 2.5 V or 5 V supply?

No. The PI3B3257Q is specified only for 3.3 V ±10% operation (2.97–3.63 V). At 2.5 V, RON increases significantly and logic thresholds become unreliable; at 5 V, absolute maximum ratings are exceeded, risking permanent damage. Its rail-to-rail input tolerance (up to 3.6 V) does not extend to VCC.

Is PI3B3257Q suitable for analog audio signal switching?

Yes-within limits. With 5 Ω RON and 3.0 pF CIN, it supports audio-band analog signals up to ~200 kHz with <0.01% THD+N at ≤1 VPP. However, it lacks dedicated audio-grade specifications (e.g., click/pop suppression), so DC-coupled headphone paths require external blocking capacitors and biasing.

What is the thermal pad requirement for PI3B3257Q?

None-the QSOP-16 (Q) package has no exposed thermal pad. Thermal dissipation relies on standard PCB copper area connected to Pins 11 (VCC) and 12 (GND). Unlike the ZHD UQFN variant, PI3B3257Q does not require soldering of an exposed center pad or thermal vias.

Does PI3B3257Q support hot-swap or live-insertion?

Only with proper sequencing: VCC and GND must be applied before any signal or control input. The device itself has no built-in hot-swap protection, but its rail-to-rail input tolerance and high-impedance disable state allow safe insertion into powered backplanes if power rails stabilize first and control lines remain inactive until sequencing completes.