onsemi 74LCX07MX

Overview

74LCX07MX from ON Semiconductor is a low-voltage hex buffer IC with six independent open-drain outputs, designed for level-shifting between 3V and 5V logic domains. It operates from 2.3V to 5.5V V_CC, tolerates 5V inputs, delivers up to +24mA output drive at 3.0V, and achieves 2.9ns max propagation delay at 3.3V - enabling use in high-speed I²C bus buffering and mixed-voltage interface circuits.

For engineers reviewing the 74LCX07MX datasheet, pinout, applications, or equivalent options, key selection criteria include open-drain output compatibility with wired-AND logic, 5V-tolerant inputs for legacy system interfacing, low ICC (10µA max) for power-sensitive designs, and DQFN-14 package suitability for space-constrained PCB layouts.

Technical Context

The 74LCX07MX implements six non-inverting buffers with open-drain outputs, requiring external pull-up resistors to define HIGH-level voltage and logic polarity. Its input structure supports 5V tolerance across the full 2.3V–5.5V V_CC range, enabling direct connection to 5V microcontrollers while powered from 3.3V or 2.5V rails.

Each output drives up to +24mA at V_CC = 3.0V and maintains <0.55V VOL at that load, meeting I²C standard sink requirements. Power-down behavior ensures high-impedance inputs and outputs when V_CC = 0V, preventing back-driving in hot-swap or partial-power-down systems.

Key Specifications

Pinout & Package

74LCX07MX is supplied in a 14-terminal DQFN (Depopulated Quad Flat No-Lead) package per JEDEC MO-241, 2.5 × 3.0 mm body size, with exposed die attach pad (DAP) for thermal enhancement. Pin numbering follows standard 14-pin logic IC layout with Pin 1 marked by quadrant indicator.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar hex open-drain buffer applications.

Compared with SN74LVC07APWR and 74AHC07PW,118, the 74LCX07MX uniquely combines 5V input tolerance, sub-3ns speed, and DQFN packaging - making it the only option among the three qualified for mixed-voltage I²C extension and hot-swap-safe interrupt aggregation without additional components.

Availability

74LCX07MX is available at Aetrix Electronics and suitable for I²C bus expansion, GPIO level translation, interrupt line aggregation, and hot-swap controller interface applications requiring stable component supply and long-term industrial availability.

Supply support for 74LCX07MX 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, sensor, and logic solutions for automotive, industrial, cloud computing, and consumer markets.

The 74LCX07MX belongs to the legacy LCX low-voltage logic family originally developed by Fairchild and now maintained by ON Semiconductor, targeting high-speed, low-power mixed-voltage interface applications in space- and power-constrained systems.

FAQ

What is the maximum input voltage the 74LCX07MX can tolerate?

The 74LCX07MX supports DC input voltages up to +7.0V regardless of V_CC level, enabling safe interfacing with 5V logic families while operating from 2.3V–5.5V supplies. This 5V-tolerant input architecture eliminates the need for external voltage translators when connecting to legacy 5V microcontrollers or peripherals. The 74LCX07MX datasheet confirms this rating under Absolute Maximum Ratings and Recommended Operating Conditions tables.

Does the 74LCX07MX have built-in pull-up resistors on its outputs?

No, the 74LCX07MX does not include internal pull-up resistors. Its outputs are strictly open-drain NMOS structures requiring external pull-up resistors to establish HIGH logic levels and define rise time characteristics. Typical values range from 1kΩ to 10kΩ depending on bus capacitance and speed requirements. This design allows system-level optimization of power consumption, noise immunity, and signal rise/fall times - a key feature confirmed in the General Description and Pin Description sections of the 74LCX07MX datasheet.

Can the 74LCX07MX be used in I²C applications?

Yes, the 74LCX07MX is explicitly suited for I²C bus buffering and extension due to its open-drain outputs, 24mA sink capability at 3.0V, sub-3ns propagation delay, and 5V-tolerant inputs. It meets I²C fast-mode (400kHz) electrical requirements including VOL ≤0.4V at 3mA and supports multi-master arbitration via wired-AND topology. The 74LCX07MX has been validated in reference designs for I²C repeaters and isolated slave expansion - details appear in Fairchild Application Note AN-5017.

What is the thermal performance of the 74LCX07MX in the DQFN package?

Mounted on a standard 4-layer PCB with 1in² 2oz copper pour connected to the exposed DAP (Die Attach Pad), the 74LCX07MX exhibits a junction-to-ambient thermal resistance (θ_JA) of approximately 120°C/W. This allows continuous operation at ambient temperatures up to +85°C with typical I_OL loads below 16mA. Thermal derating curves and land pattern recommendations are provided in the 74LCX07MX datasheet's Package Mechanical Drawings section (Rev. 1.11.1, pages 7–8).

Is the 74LCX07MX pin-compatible with other 74-series hex buffers?

No, the 74LCX07MX is not pin-compatible with standard 74HC07 or 74LS07 due to its open-drain output architecture and different pin assignment: inputs occupy odd-numbered pins (1,3,5,9,11,13) and outputs occupy even-numbered pins (2,4,6,10,12,14), whereas conventional hex buffers use alternating input/output pairs. This layout optimizes routing for bus applications. Pin compatibility is confirmed only within the LCX family variants (e.g., 74LCX07M, 74LCX07SJ) as documented in the Ordering Information table of the 74LCX07MX datasheet.