Diodes Incorporated PI3USB20LEX

Overview

PI3USB20LEX from Diodes Incorporated (acquired Pericom) is a 4-channel, 2:1 bidirectional USB 2.0 analog multiplexer/demultiplexer switch with 4Ω typical on-resistance, <250ps propagation delay, and 500MHz bandwidth. It routes differential D+/D− signals between a USB host and one of two downstream ports in portable docking stations and multi-peripheral USB hubs.

For engineers reviewing the PI3USB20LEX datasheet, PI3USB20LEX pinout, PI3USB20LEX application, or PI3USB20LEX equivalent, key selection criteria include sub-250ps propagation delay, ≤200ps bit-to-bit skew, –27dB crosstalk at 250MHz, 6pF channel on-capacitance, and 3.0–3.6V VCC operation for high-fidelity 480Mbps USB 2.0 signal integrity.

Technical Context

The PI3USB20LEX implements a CMOS-based analog switch architecture optimized for differential USB 2.0 signaling, supporting bidirectional 480Mbps data flow without signal inversion or level translation. Its low R_ON (4Ω typ.) and matched flatness (1.0Ω max) minimize insertion loss and amplitude imbalance across all four channels.

Control logic uses a single active-high SEL pin to select between two input pairs (0I0/0I1 and 1I0/1I1) for each Yn output, with Hi-Z outputs when disabled. Propagation delay is dominated by RC time constant (R_ON × C_ON ≈ 0.25ns for 10pF load), not gate delay, enabling near-transparent signal routing.

Key Specifications

Pinout & Package

PI3USB20LEX is housed in a Pb-free, green-compliant 16-pin TSSOP (L) package, 4.4mm × 5.0mm body, 0.65mm pitch, with exposed thermal pad (not electrically connected). Pin 1 marked via dot; pin 16 = V_DD, pin 8 = GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB 2.0 analog switch applications.

Compared with TS3USB221E and MAX4989, PI3USB20LEX delivers superior channel density, lowest propagation delay, and tightest R_ON matching-making it optimal for multi-lane, timing-critical USB 2.0 routing where signal fidelity and skew control are primary constraints.

Availability

PI3USB20LEX is available at Aetrix Electronics and suitable for USB-C docking stations, industrial peripheral selectors, embedded test equipment, and multi-port USB 2.0 hubs requiring stable component supply and long-term design-in support.

Supply support for PI3USB20LEX 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 semiconductor company specializing in discrete, analog, and mixed-signal ICs, with broad portfolio coverage in connectivity, power management, and signal integrity solutions.

PI3USB20LEX belongs to Diodes' high-speed analog switch product line, engineered specifically for USB 2.0, HDMI, and DisplayPort signal routing in space-constrained, high-reliability consumer and industrial systems.

FAQ

What is the maximum data rate supported by PI3USB20LEX?

The PI3USB20LEX supports full USB 2.0 high-speed operation at 480Mbps, validated by its 500MHz –3dB bandwidth and <250ps propagation delay. Measured crosstalk of –27dB at 250MHz and 200ps bit-to-bit skew ensure compliance with USB 2.0 eye diagram and jitter specifications under real-world PCB trace conditions.

Does PI3USB20LEX require external biasing or termination resistors?

No. PI3USB20LEX operates as a passive analog switch with no internal biasing circuitry; it requires only a 3.0–3.6V V_DD supply and proper 100nF local decoupling. External 90Ω differential termination is handled by the connected USB transceivers-not the switch-so no additional resistors are needed on the switch path.

Can PI3USB20LEX be used with USB 3.x or SuperSpeed signals?

No. PI3USB20LEX is specified only for USB 2.0 (480Mbps) operation. Its 500MHz bandwidth and lack of SuperSpeed (5Gbps+) equalization or protocol awareness make it incompatible with USB 3.0/3.1/3.2 differential pairs. Using it with SS signals would cause severe signal degradation and link training failure.

How does the SEL pin function in PI3USB20LEX?

The SEL pin is a single active-high digital control input that selects between two input sets: logic low connects each Yn output to corresponding nI0 terminals (e.g., Y0→0I0); logic high connects Yn to nI1 terminals (e.g., Y0→0I1). It has rail-to-rail voltage tolerance (0–3.6V), allowing direct drive from 1.8V, 3.3V, or 5V GPIOs without level shifters.