Diodes Incorporated PI3B34X245BEX

Overview

PI3B34X245BEX from Pericom Semiconductor is a 3.3V, 32-bit, 2-port bus switch with four independent active-low enable inputs (BE1–BE4), 5 Ω on-resistance, 4.5 ns max bus disable time, and ultra-low quiescent current (1.0 µA typical), used for high-speed bidirectional data routing in notebook memory expansion subsystems.

For engineers reviewing the PI3B34X245BEX datasheet, PI3B34X245BEX pinout, PI3B34X245BEX application, or PI3B34X245BEX equivalent, key selection criteria include TTL-compatible control logic, near-zero propagation delay, rail-to-rail input tolerance up to +3.6V, industrial temperature range (–40°C to +85°C), and Pb-free 80-pin BQSOP packaging.

Technical Context

The PI3B34X245BEX implements four independent 8-bit switch banks (BE1–BE4), each connecting corresponding A- and B-side 32-bit buses bidirectionally when enabled. Each bank supports 5 Ω R_ON at V_CC = 3.3V and I_ON = 48 mA, with COFF = 8.0 pF and CON = 16.0 pF.

It uses CMOS transmission-gate architecture with no internal latching or buffering-signals pass through with only RC delay (<0.25 ns time constant into 50 pF load). Control inputs tolerate 0–3.6V regardless of V_CC, enabling mixed-voltage interface bridging without level shifters.

Key Specifications

Pinout & Package

Package: 80-pin, 150-mil wide plastic BQSOP (Pb-free & Green), 5.80–6.20 mm width, 20.40–20.60 mm length, 0.803–0.811 mm thickness per JEDEC MO-154C/BC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 32-bit bidirectional bus switch applications.

Compared with SN74CBT3245APM and PI3CH485BEX, the PI3B34X245BEX uniquely delivers 32-bit width, 5 Ω R_ON, and 4 independent enables in a single BQSOP package-making it optimal for notebook memory expansion where density, speed, and low standby power are jointly constrained.

Availability

PI3B34X245BEX is available at Aetrix Electronics and suitable for notebook memory expansion, PCIe sideband routing, embedded debug trace multiplexing, and industrial CPU bus isolation requiring stable component supply and long-term lifecycle support.

Supply support for PI3B34X245BEX 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 (acquired by Diodes Incorporated in 2016) specialized in high-speed interface ICs, clock management, and signal-integrity solutions for computing and communications markets.

The PI3B34X245 belongs to Pericom's NanoSwitch™ family-designed specifically for low-latency, low-power, bidirectional bus switching in portable and embedded systems with strict thermal and footprint constraints.

FAQ

What is the maximum allowable input voltage on control pins when V_CC = 3.3V?

The PI3B34X245BEX control inputs (BEn) tolerate –0.5 V to +3.6 V regardless of V_CC level. This rail-to-rail input specification allows safe interfacing with 3.3V logic families even under transient overvoltage conditions, eliminating the need for external clamping diodes or level shifters in standard notebook designs.

Does the device introduce measurable propagation delay in signal paths?

No-the PI3B34X245BEX contributes no intrinsic propagation delay beyond the RC time constant of its 5 Ω R_ON and load capacitance. With a 50 pF load, this time constant is ~0.25 ns, which is significantly smaller than typical driver rise/fall times; measured t_PLH/t_PHL is 0.25 ns max, confirming near-zero added latency.

Can all 32-bit channels be enabled simultaneously using a single BE signal?

No-BE1–BE4 are independent enables, each controlling an 8-bit segment (BE1: A0–A7/B0–B7; BE2: A8–A15/B8–B15; etc.). To enable all 32 bits, all four BE pins must be driven LOW. There is no global enable; this segmentation allows partial bus isolation for power gating or fault containment.

Is the PI3B34X245BEX compatible with hot-plug insertion of memory modules?

Yes-its rail-to-rail input tolerance, high-impedance OFF-state (Hi-Z), and fast disable time (1.0–4.5 ns) meet hot-plug requirements. When BE is HIGH, A/B ports present 8.0 pF C_OFF and ±1 µA leakage, preventing back-driving or latch-up during live insertion of SO-DIMMs in notebook platforms.