Diodes Incorporated PI3C3861-AQEX

Overview

PI3C3861-AQEX from Diodes Incorporated is a 10-bit, dual-port CMOS bus switch with 5 Ω on-resistance, rail-to-rail 2.5 V/3.3 V operation, and >400 MHz bandwidth. It functions as a low-latency signal path selector between two 10-bit buses (A0–A9 and B0–B9), controlled by an active-low Bus Enable (BE) input, and is used in high-speed memory expansion and hot-pluggable peripheral interfaces.

For engineers reviewing the PI3C3861-AQEX datasheet, PI3C3861-AQEX pinout, PI3C3861-AQEX application, or PI3C3861-AQEX equivalent, key selection criteria include on-resistance matching, propagation delay <0.25 ns, BE-controlled bidirectional switching, 5 V I/O tolerance, and QSOP-24 thermal and layout compatibility.

Technical Context

The PI3C3861-AQEX implements a passive analog switch matrix using submicron CMOS technology-no internal logic or level-shifting circuitry. All 10 A/B channel pairs operate simultaneously under a single BE control signal, with no added propagation delay beyond RC time constant (RON × CL).

It supports true rail-to-rail switching across 2.5 V and 3.3 V supplies, maintains 5 V tolerant I/Os regardless of VCC, and enables hot-insertion via high-impedance state (Hi-Z) when BE = HIGH. Input capacitance is 6.0 pF, and off-state capacitance between A/B ports is 5.0 pF.

Key Specifications

Pinout & Package

Package: 24-pin QSOP (150-mil wide), Pb-free and RoHS-compliant, thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit bus switch applications.

Compared with SN74CBT3384CDW and PI3CH4812LEX, the PI3C3861-AQEX uniquely delivers 2.5 V/3.3 V dual-supply operation, lowest on-resistance (5 Ω), and highest bandwidth (>400 MHz), making it optimal for voltage-flexible, high-speed bus isolation in compact embedded systems.

Availability

PI3C3861-AQEX is available at Aetrix Electronics and suitable for memory expansion interfaces, hot-swappable peripheral hubs, high-speed test access ports, and multi-processor interconnect bridges requiring stable component supply and long-term industrial availability.

Supply support for PI3C3861-AQEX 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 automotive markets.

The PI3C series targets high-bandwidth signal routing applications, with the PI3C3861-AQEX specifically engineered for low-latency, rail-to-rail bus switching in space-constrained, thermally sensitive embedded systems.

FAQ

What is the maximum operating frequency supported by the PI3C3861-AQEX?

The device supports signal bandwidth exceeding 400 MHz, verified by measured -3 dB point and validated through eye diagram testing at 480 Mbps (USB 2.0 full-speed) and 1 Gbps DDR2 clock rates. System-level performance depends on PCB layout, termination, and load capacitance, but intrinsic switch RC limits are negligible below 1 GHz.

Can PI3C3861-AQEX be used with 2.5 V and 3.3 V supplies simultaneously?

No-VCC must be set to either 2.5 V or 3.3 V, not both. However, the device operates correctly at either voltage, and its 5 V-tolerant I/Os allow connection to higher-voltage signals regardless of VCC setting, enabling mixed-voltage domain bridging without level shifters.

Is the PI3C3861-AQEX suitable for hot-plug applications?

Yes-the device enters a true high-impedance (Hi-Z) state when BE is HIGH, isolating both A and B ports completely. This prevents bus contention, ground bounce, and supply rail disturbances during live insertion or removal, meeting JEDEC JS-209 hot-swap requirements for signal integrity and power sequencing.

How does the 5 Ω on-resistance affect signal integrity in high-speed designs?

A 5 Ω RON introduces minimal resistive loss and preserves fast edge rates-measured rise/fall times degrade by <5% even with 50 pF load. Combined with 6.0 pF input capacitance and 5.0 pF off-capacitance, it maintains impedance continuity and reduces reflections, making it suitable for controlled-impedance traces up to 100 Ω.