Diodes Incorporated PI3B3245LEX

Overview

PI3B3245LEX from Diodes Incorporated is a 3.3V, 8-bit, 2-port bus switch with active-low Bus Enable (BE), 5Ω on-resistance, 4.5ns max switching time, and ultra-low quiescent current (0.2μA typical), designed for hot-insertion in notebook and portable computing systems.

For engineers reviewing the PI3B3245LEX datasheet, PI3B3245LEX pinout, PI3B3245LEX application, or PI3B3245LEX equivalent, key selection criteria include TTL-compatible control logic, rail-to-rail input tolerance up to +3.6V, near-zero propagation delay contribution, and support for high-impedance isolation during hot-swap events.

Technical Context

The PI3B3245LEX implements an array of eight independent bilateral analog switches controlled by a single active-low BE signal, enabling simultaneous connection or disconnection between two 8-bit parallel buses (A0–A7 and B0–B7). Each switch exhibits matched 5Ω on-resistance and <0.25ns intrinsic propagation delay under 50pF load.

It operates within –40°C to +85°C ambient, supports 3.3V ±10% supply, tolerates input voltages up to +3.6V regardless of VCC, and integrates ESD protection rated at 2kV HBM and 200V MM - critical for system-level hot-plug robustness in mobile platforms.

Key Specifications

Pinout & Package

PI3B3245LEX is packaged in a 20-pin TSSOP (173mil wide) with exposed thermal pad not present - unlike the W-QFN variant. Pin 10 is GND, Pin 20 is VCC, Pin 19 is active-low BE, Pins 2–9 are bidirectional A0–A7, Pins 11–18 are bidirectional B0–B7, and Pin 1 is NC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit bus switch applications.

Compared with SN74CBT3245APW and PI3CH4812LE, the PI3B3245LEX uniquely combines true bidirectionality, hot-insertion readiness, and sub-5Ω on-resistance in a 3.3V package - making it optimal for space-constrained, battery-sensitive notebook and docking applications requiring zero-latency bus gating.

Availability

PI3B3245LEX is available at Aetrix Electronics and suitable for notebook memory expansion, hot-swappable docking stations, LPC bus isolation, and PCIe sideband routing requiring stable component supply and long-term lifecycle assurance.

Supply support for PI3B3245LEX 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 PI3B3245LEX belongs to Diodes' Pericom® NanoSwitch™ product line, engineered specifically for low-latency, low-power, hot-pluggable signal routing in portable and embedded computing platforms.

FAQ

What is the maximum recommended load capacitance for reliable PI3B3245LEX switching?

The datasheet specifies guaranteed performance with CL = 50pF and RL = 500Ω. Measured tPLH/tPHL remain ≤0.25ns under this condition. For loads exceeding 50pF, propagation delay increases linearly with RC time constant (RON × CL); design margin should maintain total delay <1ns for 100MHz-equivalent edge rates.

Can PI3B3245LEX operate with VCC = 2.5V?

No - the PI3B3245LEX is specified only for 3.3V ±10% (2.97V to 3.63V). At 2.5V, VIH/VIL thresholds become undefined, RON rises significantly (>15Ω), and ESD clamps may not activate properly. Use PI3B3126 or PI3CH4812 for 2.5V-compatible alternatives.

Is the NC pin (Pin 1) required to be left floating or grounded?

Pin 1 is marked NC (No Connect) in both QSOP and TSSOP packages and must remain unconnected - neither grounded nor tied to VCC. Internal circuitry has no bond wire or silicon connection to this pin; soldering or routing to it may cause mechanical stress or unintended coupling.

Does PI3B3245LEX support partial power-down (e.g., VCC off while I/Os active)?

No - the device requires VCC to be present and stable before applying any signals to A/B or BE pins. Applying inputs with VCC = 0V violates absolute maximum ratings and risks latch-up or permanent damage. Power sequencing must follow VCC→GND→inputs order per datasheet guidelines.