onsemi MC79L15ACD

Overview

MC79L15ACD from ON Semiconductor is a fixed-output, 100 mA negative voltage regulator delivering −15 V with ±4% output tolerance (−14.4 V to −15.6 V at +25°C), 1.7 V dropout at 40 mA, and integrated thermal shutdown and short-circuit current limiting. It operates across 0°C to +125°C and is used for on-card regulation in industrial control interfaces, sensor biasing, and analog signal conditioning where stable negative rail generation is required.

For engineers reviewing the MC79L15ACD datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed −15 V output accuracy over temperature, SOIC-8 package thermal performance (R_JA = 180°C/W), ripple rejection of 34–39 dB at 120 Hz, and compatibility with standard 0.33 µF input / 0.1 µF output capacitor configurations.

Technical Context

The MC79L15ACD implements a monolithic bipolar linear regulator architecture with internal bandgap reference, error amplifier, pass transistor, and protection circuitry. Its three-terminal configuration (Input, Ground, Output) requires no external feedback components and supports operation with input voltages from −17.5 V to −30 V under nominal load.

It features fixed-voltage regulation without trimming capability, uses internal current limiting to cap output at ~150 mA during overload, and relies on junction-to-ambient thermal resistance (180°C/W in SOIC-8) to define safe power dissipation limits - requiring derating above +50°C ambient per Figure 8.

Key Specifications

Pinout & Package

MC79L15ACD is housed in an SOIC-8 (Case 751) surface-mount package with exposed pad not electrically connected. Pin 1 is Ground, Pin 2 is Input (−Vin), Pin 3 is Output (−Vout); Pins 4 and 8 are No Connect; Pins 5–7 are internally tied to Input (−Vin).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative voltage regulation applications.

Compared with LM7915CD and MC79L15ACPG, the MC79L15ACD offers optimal surface-mount integration for space-constrained industrial PCBs, balancing thermal performance (180°C/W), RoHS compliance, and proven reliability in automotive-qualified variants - making it preferred for volume production of compact analog subsystems.

Availability

MC79L15ACD is available at Aetrix Electronics and suitable for industrial sensor interfaces, embedded analog peripherals, and RS-232 transceiver biasing requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for MC79L15ACD 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 (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The MC79L00A Series was designed specifically for cost-sensitive, low-current negative voltage regulation in industrial controls, instrumentation, and legacy communication interfaces - emphasizing ruggedness, simplicity, and long-term manufacturability.

FAQ

What is the maximum input voltage rating for MC79L15ACD?

The MC79L15ACD supports a maximum input voltage of −30 V DC under normal operating conditions (TA = +25°C). At −30 V input, the device maintains regulation as long as output current remains ≤100 mA and junction temperature stays below +150°C. Exceeding −30 V risks permanent damage per Absolute Maximum Ratings table on page 2 of the datasheet.

Does MC79L15ACD require input and output capacitors for stable operation?

Yes, MC79L15ACD requires a 0.33 µF input capacitor (tantalum, mylar, or low-ESR ceramic) placed directly across Pins 2 and 1, and a 0.1 µF output capacitor (ceramic) across Pins 3 and 1. These capacitors ensure stability, improve transient response, and suppress high-frequency noise - especially critical when input trace length exceeds 5 cm or load capacitance exceeds 10 µF.

Can MC79L15ACD be used in automotive applications?

The MC79L15ACD is rated for 0°C to +125°C operation and meets industrial temperature requirements, but it is not AEC-Q100 qualified. For automotive use, ON Semiconductor offers the MC79L15AB variant (−40°C to +125°C, automotive-grade test flow). MC79L15ACD may be deployed in non-safety-critical cabin electronics only after full system-level qualification by the end customer.

What is the thermal resistance (R_JA) of MC79L15ACD in its SOIC-8 package?

The MC79L15ACD has a junction-to-ambient thermal resistance (R_JA) of 180°C/W in the SOIC-8 (Case 751) package, measured using the minimum recommended copper pad size per Figure 9. Actual R_JA improves with larger copper areas - e.g., 2.8 mm² pad reduces R_JA to ~130°C/W - enabling higher continuous power dissipation in thermally optimized layouts.

How does MC79L15ACD handle short-circuit conditions?

MC79L15ACD incorporates internal short-circuit current limiting that caps output current at approximately 150 mA during sustained overload or output short. This feature, combined with thermal shutdown at +150°C junction temperature, protects both the MC79L15ACD and upstream power sources from damage during fault conditions without requiring external current-sense circuitry.