Diodes Incorporated PI5C3126LE

Overview

PI5C3126LE from Pericom Semiconductor is a 4-bit bus switch IC with four individually controllable active-HIGH enable inputs, 5Ω on-resistance switches, near-zero propagation delay (0.25 ns), and ultra-low quiescent current (0.1 µA typical), used for bidirectional signal routing in notebook and low-power embedded bus isolation applications.

For engineers reviewing the PI5C3126LE datasheet, PI5C3126LE pinout, PI5C3126LE application, or PI5C3126LE equivalent, key selection criteria include individual enable polarity, ON-resistance tolerance at 5V, high-impedance isolation leakage, bus disable timing (tPHZ/tPLZ ≤ 4.7 ns), and QSOP-16 thermal and mechanical compatibility.

Technical Context

The PI5C3126LE implements four independent analog bus switches using NMOS pass-transistor topology, each controlled by a dedicated active-HIGH BE pin. It operates at VCC = 4.5–5.5 V, supports bidirectional DC-coupled signal flow between A and B ports, and introduces no logic-level translation or added propagation delay beyond RC time constant of Ron and load capacitance.

Its control logic requires no external pull-up for power-up stability (unlike PI5C3125), and all A/B I/O pins tolerate –0.5 V to +7.0 V, enabling hot-swap and mixed-voltage domain interfacing. The device draws only 0.1 µA ICC in static state and exhibits 6 pF input capacitance and 8 pF ON-state A/B capacitance.

Key Specifications

Pinout & Package

PI5C3126LE is housed in a 16-pin QSOP (Q) package with 150-mil body width, JEDEC MO-137B-compliant leadform, and Pb-free/Green construction (E suffix). Pin 1 is VCC; Pin 16 is GND; Pins 9–12 and 14–15 are functional I/O; Pin 13 is NC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3126PW and PI5C3125LE, PI5C3126LE offers the lowest quiescent current for battery-sensitive designs while retaining identical pinout and switching performance-making it optimal for portable systems requiring long idle duration.

Availability

PI5C3126LE is available at Aetrix Electronics and suitable for notebook platform design, LPC bus expansion, PCIe lane management, and industrial backplane isolation requiring stable component supply and long-term lifecycle support.

Supply support for PI5C3126LE 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, timing, and signal-integrity solutions for computing, communications, and consumer electronics before its 2017 acquisition.

The PI5C3126LE belongs to Pericom's 5C-series low-power bus switch product line, engineered specifically for zero-delay, low-leakage signal routing in space-constrained and power-sensitive portable platforms.

FAQ

What is the maximum allowable voltage on A/B pins relative to GND?

The A and B pins tolerate –0.5 V to +7.0 V regardless of VCC state, enabling robust hot-swap operation and mixed-voltage domain interfacing. This rating is absolute and applies even when the device is unpowered, provided VCC remains within –0.5 V to +7.0 V.

Does PI5C3126LE require external pull-up resistors on BE pins?

No. Unlike the PI5C3125 (active-LOW), the PI5C3126LE's active-HIGH BE inputs do not require external pull-ups for power-up default isolation. Internal circuitry ensures high-impedance state at power-on if BE pins float, though tying them to GND or VCC via MCU GPIO is recommended for deterministic behavior.

Can PI5C3126LE be used with 3.3V logic systems?

Yes. While optimized for 5V VCC operation, the device accepts 3.3V control signals on BE pins (Vih = 2.0 V min) and passes 3.3V signals bidirectionally on A/B ports. Its –0.5 V to +7.0 V I/O tolerance allows direct connection to 3.3V peripherals without level shifters, provided VCC = 5V is supplied.

Is there a thermal derating requirement for continuous 120mA output current?

No. The 120mA DC output current rating is absolute maximum-not sustained. Continuous current must be limited by power dissipation: at 5Ω Ron and 120mA, power per switch is 72mW. With four switches active simultaneously, total die power must stay below 0.5W (max rated), requiring board-level thermal management above ~60mA average per channel in enclosed environments.