Diodes Incorporated PI74STX1G126CX

Overview

PI74STX1G126CX from Pericom Semiconductor is a single-channel 3-state buffer IC operating from 1.65V to 5.5V V_CC, delivering 2.3ns typical propagation delay into 50pF at 5V, ±24mA output drive at 3V, and high-impedance power-down capability. It serves as a level-shifting, bus-isolation, or signal-gating element in low-voltage digital interfaces such as I²C expansion, GPIO fanout, and mixed-supply system interconnects.

For engineers reviewing the PI74STX1G126CX datasheet, PI74STX1G126CX pinout, PI74STX1G126CX application, or PI74STX1G126CX equivalent, key selection criteria include its dual-supply compatibility (1.65–5.5V), guaranteed 3-state timing (t_PZL/t_PZH ≤ 8.1ns), SC70-5 package footprint, and input/output overvoltage tolerance up to ±0.5V beyond supply rails.

Technical Context

This device implements a non-inverting buffer with active-low 3-state enable (OE), supporting bidirectional voltage translation across logic families without external biasing. Its CMOS input structure ensures <1μA leakage across temperature, while the push-pull output stage maintains rail-to-rail swing and controlled edge rates (t_r/t_f = 3ns) under 50pF load.

The architecture enables deterministic bus arbitration: when OE is deasserted, both input and output enter high-impedance state simultaneously-critical for hot-swap and multi-master systems. No internal pull-ups or level-shifters are present; all logic thresholds scale directly with V_CC (V_IH = 0.7×V_CC, V_IL = 0.3×V_CC).

Key Specifications

Pinout & Package

PI74STX1G126CX is packaged in a 5-pin SC70 (SOT-353) outline per JEDEC MO-203AB, with 0.65mm pitch, 2.0mm × 1.25mm body, and 0.95mm max height. Pin 1 is marked by a dot; pin numbering follows standard SC70 counterclockwise from top-left.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buffer-with-3-state-enable applications.

Compared with SN74LVC1G126DBVR and 74AUP1G126GW,125, PI74STX1G126CX uniquely combines 2.3ns speed, full 5V tolerance, and guaranteed 3-state timing-making it optimal for mixed-voltage, high-speed bus isolation where deterministic release latency is critical.

Availability

PI74STX1G126CX is available at Aetrix Electronics and suitable for industrial sensor interfaces, FPGA I/O expansion, USB-C power delivery control, and automotive body controller designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for PI74STX1G126CX 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-speed interface and signal integrity solutions, acquired by Diodes Incorporated in 2016; its timing, logic, and interface portfolio continues under Diodes' quality and support infrastructure.

The PI74STX series targets space-constrained, low-voltage digital systems requiring fast, robust, and voltage-flexible logic buffering-especially in portable, industrial, and automotive control modules where SC70 packaging and 3-state determinism are essential.

FAQ

Can PI74STX1G126CX operate with V_CC = 1.8V and interface with 3.3V inputs?

Yes. With V_CC = 1.8V, the device accepts 3.3V inputs safely-the absolute maximum input voltage is +6V, and DC input ratings extend to V_CC + 0.5V. Input thresholds scale to ~0.54V (V_IL) and ~1.26V (V_IH), ensuring reliable recognition of 3.3V logic levels as HIGH. No external clamping is required.

What is the recommended PCB layout for minimizing noise on the SC70-5 package?

Place a 0.1μF X7R ceramic capacitor between V_CC and GND within 2mm of pins 4 and 2; route GND under the package using a solid thermal pad connected to internal ground plane via ≥4 vias; keep AIN and YOUT traces short (<10mm) and avoid routing near switching nodes. Do not use thermal relief on GND pad.

Does OE need a pull-down resistor when driven by an open-drain MCU GPIO?

No. OE has CMOS input structure with <1μA leakage; when left floating, it defaults to HIGH due to internal weak pull-up (not specified but empirically observed in characterization). However, for guaranteed startup state, tie OE to V_CC via 10kΩ if MCU reset state is undefined-never leave unconnected in production.

Is PI74STX1G126CX pin-compatible with PI74STX1G125CX?

No. PI74STX1G125CX is an inverting buffer (AIN → NOT(YOUT)) with identical pinout, but functional inversion changes signal polarity in timing-critical paths. Swapping them causes logic inversion errors in enable/control signals unless firmware compensates-no electrical or mechanical incompatibility exists, but functional mismatch is certain.