Diodes Incorporated PI5C3125WE

Overview

PI5C3125WE from Pericom Semiconductor is a 4-bit bus switch IC with four independent active-low enable-controlled 5Ω analog switches, designed for bidirectional signal routing in 5V TTL/CMOS systems. It features near-zero propagation delay (0.25 ns), ultra-low quiescent current (0.1 µA typical), and direct A-to-B bus connection with high-impedance isolation when disabled - used in notebook I/O expansion and system-level address/data bus gating.

For engineers reviewing the PI5C3125WE datasheet, PI5C3125WE pinout, PI5C3125WE application, or PI5C3125WE equivalent, key selection criteria include individual enable control logic, on-resistance consistency across channels, thermal performance at 85°C ambient, and QSOP-16 footprint compatibility with legacy 74XX125 layouts.

Technical Context

The PI5C3125WE implements four independent CMOS transmission-gate-based bus switches, each controlled by a dedicated active-low BE_n input. Its architecture eliminates added propagation delay beyond RC time constant (R_ON × C_L), with no ground bounce generation during switching.

It operates strictly within 4.5V–5.5V V_CC, supports ±120mA DC output current per channel, and maintains guaranteed logic thresholds (V_IH ≥ 2.0V, V_IL ≤ 0.8V) over –40°C to +85°C ambient range - enabling reliable use in portable computing power-constrained environments.

Key Specifications

Pinout & Package

Package: 16-pin QSOP (150-mil wide), Pb-free & RoHS-compliant (Q suffix), body dimensions 3.99 mm × 4.80 mm × 1.35 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit bus switch applications.

Compared with SN74CBT3125PW and 74LVC1G3157GW, the PI5C3125WE offers native active-low enable alignment with legacy 74-series designs, lowest R_ON among QSOP-packaged 4-bit switches, and proven thermal stability up to +85°C - making it optimal for cost-sensitive, high-volume notebook and industrial control deployments.

Availability

PI5C3125WE is available at Aetrix Electronics and suitable for mobile notebook I/O expansion, LPC bus isolation, and PCIe sideband signal multiplexing requiring stable component supply and long-term manufacturing continuity.

Supply support for PI5C3125WE 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-performance interface, timing, and signal integrity solutions, acquired by Diodes Incorporated in 2016; its legacy portfolio remains widely deployed in computing and communications infrastructure.

The PI5C3125WE belongs to Pericom's 5C-series low-power bus switch family, engineered specifically for energy-efficient signal routing in portable and embedded systems operating at 5V with strict thermal and EMI constraints.

FAQ

What is the maximum continuous current rating per channel on the PI5C3125WE?

The PI5C3125WE supports up to ±120mA DC output current per A/B channel, verified under maximum ratings conditions. This allows safe operation with typical 5V TTL loads drawing ≤24mA per line while maintaining R_ON-limited voltage drop below 100mV. Exceeding this current risks thermal shutdown or permanent damage due to localized heating in the QSOP package.

Does the PI5C3125WE require external pull-up resistors on its BE pins?

Yes - the BE0–BE3 pins are active-low and lack internal pull-ups. A 10kΩ external pull-up resistor to V_CC is required on each BE pin to ensure all switches default to high-impedance (disabled) state during power-up or reset. Omitting these resistors may cause unintended bus contention or signal corruption before firmware initializes control logic.

Can the PI5C3125WE operate reliably at 3.3V V_CC?

No - the PI5C3125WE is specified only for 4.5V to 5.5V operation. At 3.3V, R_ON increases significantly (>25Ω), V_IH/V_IL thresholds become non-compliant, and quiescent current rises unpredictably. For 3.3V systems, consider Diodes Inc.'s PI3CH400 series or ON Semiconductor's NLAS3125, both rated for 2.5–3.6V operation.

Is the PI5C3125WE pin-compatible with the obsolete 74F125?

Yes - the PI5C3125WE uses the industry-standard 74XX125 pinout in QSOP-16, matching pin-for-pin with 74F125, 74LS125, and 74HC125. All A/B/BE/V_CC/GND assignments align exactly, enabling drop-in replacement without PCB modification - provided V_CC remains at 5V and thermal design accommodates the QSOP package's lower power dissipation (0.5W max).