Diodes Incorporated PI5C3251LE

Overview

PI5C3251LE from Diodes Incorporated is an 8:1 analog multiplexer/demultiplexer bus switch with three-state output, pin-compatible with 74F251 and 74ALS/AS/LS251 logic families. It features 5Ω on-resistance, near-zero propagation delay (0.25 ns), ultra-low quiescent current (0.2 µA typical), and operates over –40°C to +85°C ambient with 5V ±5% supply. It enables high-fidelity signal routing in notebook I/O expansion and low-power embedded data buses.

For engineers reviewing the PI5C3251LE datasheet, PI5C3251LE pinout, PI5C3251LE application, or PI5C3251LE equivalent, key selection criteria include guaranteed 5Ω R_ON, sub-nanosecond t_IY, 3-state enable control (E), 8-channel select logic (S2–S0), and QSOP-16 packaging for space-constrained PCB layouts.

Technical Context

The PI5C3251LE implements a single-pole, eight-throw (SP8T) analog switch architecture using NMOS pass transistors with integrated level-shifting control logic. All eight inputs (I0–I7) connect directly to the shared output Y when enabled, with no internal buffering or voltage translation - preserving signal integrity and minimizing ground bounce.

Switching is controlled by three binary select lines (S2, S1, S0) and an active-low enable (E). When E is high, Y enters high-impedance state regardless of select inputs. Propagation delay is dominated solely by RC time constant of R_ON (5 Ω) and load capacitance (e.g., 50 pF → 0.25 ns), not internal logic gates.

Key Specifications

Pinout & Package

PI5C3251LE is housed in a 16-pin, 150-mil wide QSOP (Q) package with gull-wing leads, RoHS-compliant and halogen-free per Diodes' Green specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3251PWR and 74LVC1G3157GW, PI5C3251LE delivers superior low-power performance (0.2 µA vs. 10 µA), tighter R_ON matching, and true 8:1 integration - making it optimal for space- and energy-constrained notebook and dock I/O subsystems.

Availability

PI5C3251LE is available at Aetrix Electronics and suitable for notebook docking stations, industrial sensor hubs, legacy parallel port adapters, and USB peripheral multiplexers requiring stable component supply and long-term lifecycle support.

Supply support for PI5C3251LE 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, energy-efficient solutions for consumer, industrial, and automotive markets.

The PI5C3251LE belongs to Diodes' Pericom-branded analog switch product line, engineered specifically for low-latency, low-power signal routing in portable computing and embedded I/O expansion applications.

FAQ

What is the maximum signal frequency supported by PI5C3251LE?

The PI5C3251LE supports signals up to 100 MHz with minimal degradation, based on its 5 Ω R_ON and 54 pF C_I(ON) - yielding a -3 dB bandwidth of ~600 MHz under ideal 50 Ω conditions. Real-world USB 2.0 (480 Mbps) and LPC bus operation is fully validated per Diodes' application notes.

Can PI5C3251LE operate with 3.3V logic control signals while switching 5V analog signals?

Yes - the control inputs (S2:S0, E) are 5V-tolerant and accept 3.3V logic levels when V_CC = 5V. VIH is guaranteed ≥2.0 V, and VIL ≤0.8 V, allowing direct interfacing with 3.3V microcontrollers without level shifters, while passing 5V analog signals with full R_ON spec compliance.

Is thermal derating required for continuous 120 mA current through the switch?

No - the 120 mA absolute maximum rating applies per pin under short-duration pulse conditions. For continuous DC operation, the 0.5 W power dissipation limit governs: at 5 Ω R_ON, max continuous current is √(0.5 W / 5 Ω) ≈ 100 mA. Derating is not needed below this threshold at TA ≤ +85°C with standard PCB copper pour.

Does PI5C3251LE require external pull-up or pull-down resistors on control pins?

No - the control inputs have CMOS-compatible thresholds and negligible leakage (±1 µA IIH/IIL), so they retain valid logic states without external biasing. However, pull-downs on E are recommended in systems where power sequencing may leave E floating during startup to prevent unintended switch activation.