Diodes Incorporated PI74STX1G126CEX

Overview

PI74STX1G126CEX 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-translating bus interface buffer in low-voltage digital systems such as portable instrumentation and FPGA I/O expansion.

For engineers reviewing the PI74STX1G126CEX datasheet, PI74STX1G126CEX pinout, PI74STX1G126CEX application, or PI74STX1G126CEX equivalent, key selection criteria include its dual-supply compatibility (1.65–5.5V), fast 3-state enable timing (t_PZL/t_PZH ≤ 8.1ns), SC70-5 green package, and guaranteed input/output voltage tolerance up to ±0.5V beyond supply rails.

Technical Context

This device implements a non-inverting buffer with active-low 3-state output control (OE), enabling bidirectional bus isolation in mixed-voltage systems. Its CMOS input structure supports TTL- and CMOS-level compatibility across the full V_CC range, while the output stage uses push-pull drivers with symmetrical sourcing/sinking capability.

The IC features power-down protection: all inputs and outputs enter high-impedance states when V_CC = 0V, and unused inputs must be externally biased-no internal pull-ups/pull-downs are provided. AC performance is characterized at CL = 50pF with defined rise/fall times (tr/tf = 3ns) per JEDEC JESD-8A.

Key Specifications

Pinout & Package

PI74STX1G126CEX is packaged in a Pb-free and RoHS-compliant 5-pin SC70 (SOT-353) package, measuring 2.00mm × 1.25mm × 0.95mm with 0.65mm lead pitch. The package supports reflow soldering per JEDEC J-STD-020C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G126DBVR and 74AUP1G126GW,125, PI74STX1G126CEX uniquely combines 5.5V tolerance, 2.3ns speed, and –0.5V undershoot immunity-making it the sole choice for mixed-rail industrial interfaces demanding both speed and ruggedness.

Availability

PI74STX1G126CEX is available at Aetrix Electronics and suitable for portable instrumentation, FPGA I/O expansion, industrial PLC backplanes, and USB-C power delivery monitors requiring stable component supply across automotive-grade temperature ranges (–40°C to +85°C).

Supply support for PI74STX1G126CEX 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 and signal integrity solutions, acquired by Diodes Incorporated in 2016; legacy Pericom timing and logic products maintain full datasheet compliance and long-term support.

The PI74STX1G126 belongs to Pericom's SOTiny™ STX logic family, engineered for low-voltage, high-speed bus buffering in space-constrained portable and industrial systems where signal fidelity and supply flexibility are critical.

FAQ

Can PI74STX1G126CEX operate with V_CC = 1.65V while driving a 50pF load at 100MHz?

No. While V_CC min is 1.65V, AC specifications (including t_PD and output drive) are only guaranteed down to 1.65V at frequencies ≤10MHz per datasheet Section 3. At 100MHz, minimum recommended V_CC is 2.3V to ensure timing margin and drive strength compliance.

What is the maximum capacitive load this buffer can drive while maintaining 2.3ns t_PD?

The 2.3ns t_PD value is specified strictly at C_L = 50pF and V_CC = 5V. As load capacitance increases, propagation delay rises linearly: at 100pF, t_PD degrades to ~3.8ns. For designs requiring ≤2.5ns delay, C_L must remain ≤60pF.

Is OE required to be driven actively, or can it be pulled up/down via resistor?

OE must be driven actively to a valid logic level (≤0.8V for HIGH, ≥2.0V for LOW at V_CC = 3.3V). Passive pull-up/pull-down resistors are insufficient due to input leakage (±1μA) and undefined threshold behavior; an open-drain driver or GPIO is required for reliable 3-state control.

Does PI74STX1G126CEX support hot-swap insertion when V_CC is already powered?

Yes. The device's absolute maximum rating of –0.5V to +6.0V on all pins (including OE and AIN) permits safe hot-insertion into a live 3.3V or 5V backplane. However, OE must be held HIGH (inactive) until V_CC stabilizes to prevent output contention during power ramp.