Diodes Incorporated PI3B3251QE

Overview

PI3B3251QE from Diodes Incorporated is a 3.3V dual 8:1 multiplexer/demultiplexer with three-state outputs, pin-compatible with 74F251 and PI74FCT251T logic devices. It features 5Ω on-resistance, near-zero propagation delay (0.25 ns typ.), ultra-low quiescent current (0.1 µA typ.), and operates across –40°C to +85°C ambient. Used in high-speed data routing for notebook and embedded computing systems.

For engineers reviewing the PI3B3251QE datasheet, PI3B3251QE pinout, PI3B3251QE application, or PI3B3251QE equivalent, key selection criteria include low on-resistance switching, rail-to-rail logic input tolerance up to +3.6V, TSSOP-16 packaging, and compatibility with legacy 74-series bus architectures.

Technical Context

The PI3B3251QE implements a CMOS-based analog bus switch architecture with independent enable and 3-bit select control (S0–S2), supporting bidirectional signal routing between eight inputs (I0–I7) and one output (Y). Its near-zero propagation delay arises from passive FET-switch topology-not active logic-eliminating gate delay and minimizing RC-induced skew.

All logic inputs tolerate voltages up to +3.6V regardless of VCC = 3.3V ±10%, enabling mixed-voltage interfacing. The device draws only 0.1 µA quiescent current and exhibits no ground bounce noise during switching due to absence of internal latching or clocked logic.

Key Specifications

Pinout & Package

PI3B3251QE is housed in a 16-pin, 173-mil wide thin shrink small outline package (TSSOP) with exposed pad not present and standard JEDEC-compliant footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8:1 analog/digital multiplexer applications.

Compared with SN74CBT3251PWR and PI74FCT251TQEX, PI3B3251QE delivers superior low-power performance (0.1 µA vs. 5 µA), lower on-resistance (5 Ω vs. 7 Ω), and true rail-to-rail input tolerance-making it uniquely suited for battery-sensitive and mixed-voltage analog/digital multiplexing where signal fidelity and quiescent draw are critical.

Availability

PI3B3251QE is available at Aetrix Electronics and suitable for notebook system design, embedded test instrumentation, industrial PLC I/O expansion, and high-speed logic analyzer probe multiplexing requiring stable component supply and long-term lifecycle assurance.

Supply support for PI3B3251QE 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 components for consumer, industrial, and automotive markets.

The PI3B3251QE belongs to Diodes' NanoSwitch™ bus switch product line, engineered specifically for zero-delay, low-RON signal routing in portable and space-constrained electronics where power efficiency and voltage-domain flexibility are essential.

FAQ

Is PI3B3251QE suitable for analog signal switching?

Yes. Its 5 Ω on-resistance, 72 pF on-capacitance, and absence of internal logic gates make it appropriate for DC-coupled analog signals up to ~100 MHz bandwidth. Signal distortion is dominated by external RLC loading, not internal switching artifacts.

Does PI3B3251QE require external pull-up or pull-down resistors on control pins?

No. The S0–S2 and E inputs have CMOS-compatible thresholds and do not require external biasing. However, floating control pins must be avoided; tie unused selects to GND or VCC to prevent metastability and leakage current increase.

Can PI3B3251QE operate with VCC = 2.5V?

No. The device is specified only for VCC = 3.3V ±10% (2.97V–3.63V). Operation outside this range violates Absolute Maximum Ratings and may cause undefined switching behavior or increased RON beyond 8 Ω.

What is the maximum capacitive load PI3B3251QE can drive reliably?

It supports up to 50 pF load capacitance while maintaining ≤0.25 ns propagation delay. For loads >50 pF, delay increases linearly with CLOAD × RON; signal integrity should be verified via SPICE simulation or bench measurement at target frequency.