onsemi 74AC14SJX

Overview

74AC14SJX from ON Semiconductor is a hex inverter IC with Schmitt-trigger inputs, designed for noise-immune signal conditioning in digital logic interfaces. It operates across 2.0–6.0 V supply, delivers ±24 mA output drive, exhibits 1.0 V typical hysteresis, and supports propagation delays as low as 6.0 ns at 5.0 V - enabling reliable waveform shaping in clock buffering and switch debouncing applications.

For engineers reviewing the 74AC14SJX datasheet, pinout, applications, or equivalent options, this device is selected for its rail-to-rail input thresholds, low ICC quiescent current (≤20 µA), TTL-compatible output levels, and JEDEC-standard SOP-14 package compatibility in industrial control and sensor interface designs.

Technical Context

The 74AC14SJX implements six independent CMOS inverter channels, each incorporating internal transistor-ratio-defined hysteresis to convert slow-rising/falling analog-like signals into clean digital transitions. Its Schmitt-trigger inputs provide fixed positive-going (V_t+) and negative-going (V_t−) thresholds - 2.2 V and 0.5 V respectively at V_CC = 3.0 V - ensuring immunity to input noise up to 1.2 V peak-to-peak.

This device belongs to the advanced CMOS (AC) logic family and is electrically distinct from the TTL-compatible 74ACT14 variant. It requires no external components for hysteresis, supports fan-out of ≥10 LS-TTL loads per output, and maintains stable switching behavior across –40°C to +85°C ambient temperature without external biasing.

Key Specifications

Pinout & Package

EIAJ TYPE II 14-lead Small Outline Package (SOP), 5.3 mm wide, JEDEC-compliant footprint with gull-wing leads and pin 1 identifier notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar hex Schmitt-trigger inverter applications.

Compared with SN74LV14APWR and MC74HC14ADTR2G, the 74AC14SJX offers superior speed (7 ns typ.) and balanced drive strength (±24 mA) at 5 V, making it optimal for industrial timing-critical interfaces where both noise immunity and sub-10 ns response are required.

Availability

74AC14SJX is available at Aetrix Electronics and suitable for industrial automation, sensor interface design, and embedded timing applications requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for 74AC14SJX 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, logic, and sensor solutions for automotive, industrial, and cloud infrastructure markets.

The 74AC14SJX belongs to ON Semiconductor's legacy advanced CMOS logic portfolio, originally developed by Fairchild and optimized for robust signal integrity in harsh electrical environments with minimal external components.

FAQ

What is the maximum operating temperature range for the 74AC14SJX?

The 74AC14SJX is rated for operation from –40°C to +85°C ambient temperature. This range is validated per the Recommended Operating Conditions table in the official datasheet and applies to all six inverter channels simultaneously under specified supply and load conditions. The 74AC14SJX maintains guaranteed hysteresis and propagation delay performance across this full industrial temperature span.

Does the 74AC14SJX require external pull-up or pull-down resistors on its inputs?

No, the 74AC14SJX does not require external pull-up or pull-down resistors on its inputs. Its Schmitt-trigger inputs have defined V_t+ and V_t− thresholds and negligible input leakage (±1.0 µA max.), allowing direct connection to open-drain sensors or mechanical switches without biasing. However, floating inputs must still be avoided to prevent undefined output states and increased ICC.

Can the 74AC14SJX drive a 50 pF capacitive load at 10 MHz without signal degradation?

Yes, the 74AC14SJX can reliably drive a 50 pF load at 10 MHz. Its AC Electrical Characteristics specify t_PLH/t_PHL ≤11.0 ns at CL = 50 pF and V_CC = 5.0 V, corresponding to a theoretical maximum toggle frequency of ~45 MHz. At 10 MHz, edge rise/fall times remain well within specification, and output voltage swing stays within VOH ≥4.4 V and VOL ≤0.44 V under 24 mA load.

Is the 74AC14SJX pin-compatible with the 74ACT14SJX variant?

No, the 74AC14SJX is not pin-compatible with the 74ACT14SJX in functional operation despite identical pinout and package. The 74ACT14SJX features TTL-compatible inputs (VIH = 2.0 V min., VIL = 0.8 V max.), whereas the 74AC14SJX uses CMOS-compatible thresholds (VIH ≈ 0.7×V_CC, VIL ≈ 0.3×V_CC). Interchanging them may cause logic misinterpretation in mixed-signal systems without level translation.

What is the recommended PCB layout practice for minimizing noise coupling into the 74AC14SJX V_CC pin?

Place a 0.1 µF ceramic decoupling capacitor between V_CC (pin 14) and GND (pin 7) as close as possible to the 74AC14SJX body - ideally within 2 mm trace length. Use short, wide traces and avoid routing high-speed signals adjacent to the V_CC or input pins. The 74AC14SJX datasheet specifies this practice to suppress supply-induced jitter and maintain hysteresis stability during fast output transitions.