Diodes Incorporated PI3B3861QEX

Overview

PI3B3861QEX from Pericom Semiconductor is a 3.3V, 10-bit, 2-port bus switch with 5 Ω on-resistance, active-low bus enable (BE), and 4.5 ns max switching time. It connects A0–A9 to B0–B9 bidirectionally with near-zero propagation delay and 0.1 μA typical quiescent current, used in high-speed notebook memory/data bus isolation.

For engineers reviewing the PI3B3861QEX datasheet, PI3B3861QEX pinout, PI3B3861QEX application, or PI3B3861QEX equivalent, key selection criteria include low on-resistance matching, BE-active-low timing compatibility, QSOP-24 footprint constraints, and 3.3V-only supply operation without level-shifting capability.

Technical Context

This device implements a CMOS-based analog bus switch architecture with rail-to-rail logic inputs tolerant up to +3.6V independent of VCC. All 10 bidirectional A/B channels are simultaneously controlled by a single active-low BE signal, eliminating internal latching or clocking logic.

Switching behavior is purely resistive-no propagation delay is added beyond RC time constant (≤0.25 ns for 50 pF load). The 5–8 Ω RON is measured at 0 V or 2.4 V input, with COFF = 8.0 pF and CON = 16.0 pF confirming low capacitive loading in both states.

Key Specifications

Pinout & Package

PI3B3861QEX is housed in a Pb-free, green 24-pin QSOP (150-mil wide) package with standard JEDEC MO-137B/AE dimensions: 8.74 mm × 3.99 mm × 1.75 mm height, 0.635 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3384CPWR and PI3CH480QE, PI3B3861QEX provides exact 10-bit width and lowest RON at 3.3V-only operation-ideal for compact, single-rail notebook bus isolation where voltage translation is unnecessary and bit count is fixed.

Availability

PI3B3861QEX is available at Aetrix Electronics and suitable for notebook memory isolation, display interface routing, PCIe lane sharing, and embedded controller interconnect requiring stable component supply across long-life industrial and consumer programs.

Supply support for PI3B3861QEX 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 was a fabless provider of high-speed signal integrity solutions, acquired by Diodes Incorporated in 2016; its legacy timing, switching, and interface products remain in active production and support.

The NanoSwitch™ product line delivers low-RON, low-capacitance analog bus switches for portable computing and communications equipment where power, size, and signal fidelity are co-constrained.

FAQ

Can PI3B3861QEX operate with 5V logic signals on its A/B pins?

Yes-its inputs tolerate –0.5 V to +3.6 V regardless of VCC, so 3.3V logic signals are fully compatible. However, it cannot drive 5V-tolerant loads since output swing is limited to VCC (3.3V). Applying >3.6V to any pin violates absolute maximum ratings and risks permanent damage.

Is PI3B3861QEX pin-compatible with PI3B3245QEX?

No-PI3B3245QEX is an 8-bit switch in 20-pin QSOP with different pinout: BE is on pin 1, A0–A7 occupy pins 2–9, B0–B7 occupy pins 12–19, and VCC/GND are on pins 10/20. PI3B3861QEX uses 24-pin QSOP with BE on pin 11, A0–A9 on pins 3–12, B0–B9 on pins 13–22, and VCC/GND on pins 23/24.

Does PI3B3861QEX support hot-swap or live-insertion?

It supports hot-swap only with strict power sequencing: VCC and GND must be stable before applying any signal to BE, A, or B pins. Violating this sequence may cause latch-up or excessive current draw. No internal hot-swap controllers or current limiting are integrated.

What is the maximum capacitive load PI3B3861QEX can drive reliably?

Based on switching characterization, PI3B3861QEX maintains 4.5 ns max tPZH/tPLZ with CL = 50 pF. For loads >50 pF, propagation delay increases linearly with RC time constant (RON × CL); at 100 pF, expected delay is ~0.5 ns additional. Signal integrity verification is required for loads exceeding 75 pF.