Diodes Incorporated PI5C32X245B

Overview

PI5C32X245B from Pericom Semiconductor is a 16-bit, 2-port bus switch with dual active-low enable inputs (BE1, BE2), 5Ω on-resistance, near-zero propagation delay (0.25 ns), and ultra-low quiescent current (0.2 µA typical), deployed in high-speed notebook memory expansion interfaces.

For engineers reviewing the PI5C32X245B datasheet, PI5C32X245B pinout, PI5C32X245B application, or PI5C32X245B equivalent, key selection criteria include bus isolation timing, bidirectional signal integrity at 5V TTL levels, dual-enable control logic, and BQSOP-40 thermal and routing constraints.

Technical Context

The PI5C32X245B implements a passive FET-based analog switch architecture-no internal logic or level-shifting-enabling true bidirectional, rail-to-rail signal pass-through between Bus A (A0–A15) and Bus B (B0–B15). Each switch channel exhibits matched 5Ω on-resistance and <12 pF on-capacitance.

Two independent enable pins (BE1, BE2) control separate 8-bit segments: BE1 enables A0–A7 ↔ B0–B7; BE2 enables A8–A15 ↔ B8–B15. Propagation delay is dominated solely by RC time constant (RON × CL), not internal logic, yielding sub-nanosecond system-level latency under 50 pF load.

Key Specifications

Pinout & Package

Package: 40-pin BQSOP (150-mil wide, Pb-free & Green option available as PI5C32X245BE).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit bidirectional bus switch applications.

Compared with QS32X245 and SN74CBT3245A, the PI5C32X245B delivers the lowest quiescent current and strongest noise immunity on enable inputs - critical for battery-powered and electrically harsh applications where reliability trumps marginal cost savings.

Availability

PI5C32X245B is available at Aetrix Electronics and suitable for notebook memory expansion, docking station signal routing, PCI bus extension, and industrial backplane isolation requiring stable component supply and long-term lifecycle support.

Supply support for PI5C32X245B 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 timing solutions for computing and communications infrastructure.

The PI5C32X245B belongs to Pericom's 32X-series bus switch family, engineered for zero-delay, low-power, bidirectional signal isolation in 5V memory and peripheral interconnects.

FAQ

What is the maximum capacitive load the PI5C32X245B can drive while maintaining 0.25 ns propagation delay?

The 0.25 ns propagation delay specification assumes a 50 pF load capacitance with 500 Ω termination. At higher loads (e.g., >100 pF), delay increases linearly per RC time constant (RON × CL); actual system delay must be validated with board-level simulation using 5 Ω RON and measured trace capacitance.

Can BE1 and BE2 be tied together for single-enable operation?

Yes - BE1 and BE2 may be paralleled to operate all 16 bits simultaneously. Doing so eliminates independent segment control but simplifies logic design. Ensure combined fan-out does not exceed driving gate's output capability; a 74LVC1G04 inverter is sufficient for most 3.3V control sources.

Does the PI5C32X245B support mixed-voltage operation (e.g., 3.3V logic controlling a 5V bus)?

No - the device operates only at VCC = 5 V ±10%. Input thresholds (VIH = 2.0 V, VIL = 0.8 V) are TTL-compatible but require VCC = 5 V. Driving BE inputs from 3.3V logic is acceptable if VIL/VIH margins are met, but A/B signal levels must remain within 0–5V.

Is there a recommended PCB layout practice to minimize crosstalk between adjacent A/B pairs?

Route A0–A15 and B0–B15 as tightly coupled differential-length pairs with ground guard traces between channels. Maintain ≥10 mil spacing between switch channels, place decoupling capacitors (100 nF X7R) within 5 mm of each VCC pin, and avoid routing BE traces parallel to high-speed A/B lines.