onsemi MM74C914M

Overview

MM74C914M from Fairchild Semiconductor is a monolithic CMOS hex Schmitt trigger IC with extended input voltage tolerance (V_IN = V_CC −25V to GND +25V), 3V–15V supply range, guaranteed hysteresis ≥0.2V_CC, and −40°C to +85°C operating temperature. It serves as a robust signal conditioner in level-shifting interfaces between mismatched power domains.

For engineers reviewing the MM74C914M datasheet, pinout, applications, or equivalent options, key selection factors include its extended-input-voltage protection, temperature-stable VT+ and VT− thresholds, TTL-compatible output drive, low ICC (≤600 µA at V_CC = 15V), and SOIC-14 package compatibility with industrial control and mixed-supply sensor interface designs.

Technical Context

The MM74C914M implements six independent Schmitt-trigger inverters on a single die, each featuring asymmetric input clamping diodes enabling ±25V input overvoltage tolerance relative to V_CC or GND. Its hysteresis is internally fixed and guaranteed ≥0.2V_CC across 3V–15V supply range.

Threshold voltages VT+ and VT− exhibit low temperature drift (typ. 0.0005 V/°C at V_CC = 10V), and output stages provide complementary P-channel source / N-channel sink capability with I_SOURCE = −15 mA and I_SINK = 16 mA at V_CC = 10V - sufficient for direct TTL/LPTTL interfacing without external buffers.

Key Specifications

Pinout & Package

MM74C914M is housed in a 14-lead SOIC (JEDEC MS-120, 0.150″ narrow body), package number M14A, with standard dual-in-line pin spacing and gull-wing leads compatible with surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC14DR and CD40106BM96, the MM74C914M uniquely delivers ±25V input tolerance without external components, making it irreplaceable in mixed-voltage industrial interfaces - whereas alternatives require added protection circuitry or sacrifice noise immunity and drive strength.

Availability

MM74C914M is available at Aetrix Electronics and suitable for industrial sensor interfaces, pushbutton debouncing, mixed-supply level shifting, and legacy system integration requiring stable component supply and long-term obsolescence management.

Supply support for MM74C914M 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

Fairchild Semiconductor was a leading designer of high-performance analog and mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy CMOS logic portfolio remains widely deployed in industrial and automotive systems.

The MM74C914M belongs to Fairchild's 74C CMOS logic family, engineered for robust operation in electrically noisy, multi-supply environments where input overvoltage resilience and stable hysteresis are critical design requirements.

FAQ

What is the maximum input voltage the MM74C914M can tolerate relative to V_CC?

The MM74C914M supports input voltages from V_CC −25V to GND +25V. This means when powered at V_CC = 5V, an input may safely reach −20V or +30V without damage or latch-up. This extended range is enabled by internal protection diodes and distinguishes the MM74C914M from standard Schmitt triggers. The MM74C914M datasheet confirms this rating under Absolute Maximum Ratings.

Does the MM74C914M support 3.3V operation?

Yes, the MM74C914M operates across 3V to 15V, including 3.3V nominal rails. At V_CC = 3.3V, VT+ is typ. 2.4V and VT− is typ. 0.7V, yielding ~1.7V hysteresis - sufficient for noise rejection in low-voltage embedded systems. Output levels remain rail-to-rail, and ICC stays below 20 µA. The MM74C914M is fully specified down to 3V per its DC Electrical Characteristics table.

Is the MM74C914M pin-compatible with the SN74HC14?

No, the MM74C914M is not pin-compatible with the SN74HC14. While both are hex Schmitt triggers in 14-pin packages, the MM74C914M uses pins 1–6 and 9–14 for inputs/outputs (with GND on pin 7 and V_CC on pin 14), whereas SN74HC14 assigns V_CC to pin 14 but places GND on pin 7 - same pinout. However, the MM74C914M's extended input protection alters internal routing and thermal limits; substitution requires validation of overvoltage behavior and layout review. The MM74C914M must be used per its specific connection diagram.

What is the typical propagation delay of the MM74C914M at 5V supply?

At V_CC = 5V, the MM74C914M exhibits a typical propagation delay of 220 ns (t_PHL) and 220 ns (t_PLH), with a maximum of 400 ns under worst-case conditions (CL = 50 pF, TA = 25°C). This delay is consistent across all six channels and supports reliable debouncing of mechanical switches and conditioning of slow analog signals. The MM74C914M AC Electrical Characteristics table specifies these values explicitly.

Can the MM74C914M drive standard TTL loads directly?

Yes, the MM74C914M provides TTL-compatible output drive: at V_CC = 5V, it sources −1.75 mA and sinks 1.75 mA, meeting 74L-series input requirements. At V_CC = 10V, sink/source capability increases to ±16 mA - exceeding standard TTL fan-out needs. The MM74C914M datasheet confirms "Low power TTL compatibility: Fan out of 2 driving 74L" in its Features section, validating direct interfacing without external buffers.