Diodes Incorporated PI3C3861QE

Overview

PI3C3861QE from Pericom Semiconductor is a 10-bit, dual-port, low-ON-resistance (5 Ω) bus switch operating at 2.5 V or 3.3 V supply, with rail-to-rail signal switching, 5 V I/O tolerance, and hot-insertion support. It enables high-bandwidth (>400 MHz) signal routing in backplane and docking interfaces by connecting A0–A9 to B0–B9 under active-low BE control.

For engineers reviewing the PI3C3861QE datasheet, PI3C3861QE pinout, PI3C3861QE application, or PI3C3861QE equivalent, key selection criteria include ON-resistance (5 Ω typ), propagation delay (<0.25 ns), bus enable/disable timing (1.5–6.5 ns), 5 V I/O tolerance, and QSOP-24 packaging for space-constrained PCB layouts.

Technical Context

The PI3C3861QE implements a passive analog switch matrix with no internal logic or level-shifting circuitry-signal integrity relies entirely on low R_ON (5–7 Ω) and minimal parasitic capacitance (C_IN = 3.5 pF, C_ON = 10 pF). Its BE-controlled switching path operates bidirectionally between two 10-bit buses without adding propagation delay beyond RC time constant (≈0.25 ns @ 50 pF).

It supports hot-insertion via power sequencing tolerance: V_CC can be applied before or after A/B signals, and inputs remain 5 V tolerant regardless of V_CC state. The device draws only 260–500 μA quiescent current and exhibits no ground bounce noise due to absence of internal drivers or charge pumps.

Key Specifications

Pinout & Package

PI3C3861QE is housed in a Pb-free, green-compliant 24-pin QSOP (150-mil width) package with standard 0.65 mm pitch. Pin 1 is marked by a notch or dot; thermal pad is not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3384APW and PI3CH481Q, PI3C3861QE uniquely delivers 10-bit width, 5 V I/O tolerance, and sub-0.25 ns delay in a single 24-pin QSOP-making it optimal for high-density, mixed-voltage, hot-plug-critical systems.

Availability

PI3C3861QE is available at Aetrix Electronics and suitable for PCI Express slot multiplexing, hot-swappable backplane interfaces, and DDR memory address bus sharing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for PI3C3861QE 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-speed interface and signal-integrity solutions for computing, communications, and consumer electronics before its 2016 acquisition.

The PI3C3861 series was designed specifically for high-bandwidth, hot-insertion-capable bus switching in server backplanes, docking stations, and memory subsystems-emphasizing low R_ON, zero-delay analog routing, and robust I/O tolerance.

FAQ

Is PI3C3861QE compatible with 2.5 V and 3.3 V logic simultaneously?

No-it operates from a single V_CC rail (either 2.5 V or 3.3 V), but all A/B I/O pins are 5 V tolerant regardless of V_CC level. This allows connection to 2.5 V, 3.3 V, or 5 V drivers/receivers without level shifters, provided V_CC is set to match the control logic voltage (e.g., BE input).

What is the maximum capacitive load the PI3C3861QE can drive reliably?

The device is characterized up to 50 pF load capacitance with guaranteed <0.25 ns propagation delay. For loads exceeding 50 pF, signal rise/fall times degrade predictably per τ = R_ON × C_L; at 100 pF, RC time constant remains ~0.5 ns-still within most high-speed digital timing budgets.

Does PI3C3861QE require external pull-up or pull-down resistors on BE?

Yes-BE is an active-low, CMOS-compatible input with no internal termination. A pull-up resistor (typically 4.7 kΩ to V_CC) is required to ensure defined HIGH state during power-up or when unasserted, preventing unintended bus connection during initialization.

Can PI3C3861QE be used in bidirectional data paths like I²C or SMBus?

No-it lacks built-in bus arbitration or slew-rate control required for open-drain protocols. While electrically bidirectional, it cannot handle the wired-AND behavior or clock stretching of I²C. Use dedicated I²C switches (e.g., PI3USB30/32) instead.