STMicroelectronics M74HC4049B1R

Overview

M74HC4049B1R from STMicroelectronics is a high-speed CMOS hex inverting buffer/converter with 6 independent channels, operating from 2V to 6V supply, featuring 8ns typical propagation delay at 6V, ±6mA symmetrical output drive, and input tolerance up to 13V for level-shifting applications in industrial control interfaces.

For engineers reviewing the M74HC4049B1R datasheet, M74HC4049B1R pinout, M74HC4049B1R application, or M74HC4049B1R equivalent, key selection criteria include its 13V-tolerant inputs, rail-to-rail output swing, low 1µA quiescent current at 25°C, and compatibility with legacy 74-series logic footprints in mixed-voltage system interfacing.

Technical Context

The M74HC4049B1R implements six independent two-stage CMOS inverters using silicon gate C2MOS technology, enabling high noise immunity (28% VCC) and balanced tPLH/tPHL delays. Its input protection includes dedicated VCC-side diodes rated for 13V DC, allowing safe interface between higher-voltage logic domains and 3.3V/5V systems.

It operates across −55°C to +125°C with guaranteed performance at VCC = 2–6V, supports CL = 50 pF loads, and maintains symmetrical |IOH| = IOL ≥ 6mA under specified conditions - critical for driving capacitive bus lines and TTL-compatible inputs without external level shifters.

Key Specifications

Pinout & Package

Package: Plastic DIP-16 (0.300" wide), 16-pin through-hole dual in-line package with 2.54 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar hex inverting buffer applications.

Compared with SN74HC4049N and 74VHC4049N, the M74HC4049B1R uniquely combines 13V input tolerance with full industrial temperature support and proven DIP-16 reliability - making it optimal for legacy-replacement and mixed-voltage field-deployed systems.

Availability

M74HC4049B1R is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, legacy system voltage translation, and test equipment signal conditioning requiring stable component supply and long-term obsolescence management.

Supply support for M74HC4049B1R 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power ICs, sensors, and analog/mixed-signal components for industrial, automotive, and consumer markets.

The M74HC4049B1R belongs to ST's legacy HC logic family, engineered specifically for robust voltage translation, noise-immune digital interfacing, and long-lifecycle support in mission-critical industrial control systems.

FAQ

Can M74HC4049B1R safely interface a 12V sensor output with a 3.3V microcontroller?

Yes. Its inputs tolerate up to 13V DC regardless of VCC, and outputs swing rail-to-rail (0V to VCC). With VCC = 3.3V, it accepts 12V inputs and produces clean 0V/3.3V logic levels - no external components needed. Input protection diodes and C2MOS architecture ensure reliable operation without latch-up or damage.

What is the maximum capacitive load this device can drive while maintaining specified timing?

The AC specifications are characterized at CL = 50 pF, with tPLH/tPHL up to 26 ns at VCC = 6V and CL = 150 pF. For stable operation beyond 50 pF, derate propagation delay linearly - e.g., ~13 ns increase per additional 100 pF. Output drive strength (≥6mA) supports moderate bus loading, but heavy capacitance requires local buffering.

Are pins 13 and 16 internally connected or should they be left floating?

Pins 13 and 16 are explicitly marked "NC" (Not Connected) in the official datasheet and mechanical drawings. They have no internal bond wires or circuit connection. These pins must remain unconnected - neither tied to VCC nor GND - to avoid unintended coupling or mechanical stress on the package leads.

Does M74HC4049B1R support mixed-voltage operation where inputs exceed VCC?

Yes - this is a defining feature. Inputs may exceed VCC by up to 7V (VI ≤ 13V max), enabled by dedicated input protection diodes referenced to VCC. This allows true level shifting: e.g., VCC = 3.3V with 5V or 12V inputs. The output remains constrained to 0V–VCC, preserving downstream logic compatibility.