Microchip Technology MIC79050-4.2YM

Overview

MIC79050-4.2YM from Microchip Technology is a 4.2 V fixed-output, 500 mA low-dropout linear regulator (LDO) in an 8-pin SOIC package, featuring thermal shutdown, current limiting, and reverse-battery protection; used in battery-powered instrumentation and portable medical devices requiring stable low-noise voltage regulation.

For engineers reviewing the MIC79050-4.2YM datasheet, MIC79050-4.2YM pinout, MIC79050-4.2YM application, or MIC79050-4.2YM equivalent, key selection criteria include dropout voltage at full load, quiescent current in standby mode, output voltage accuracy over temperature, and reverse-polarity fault resilience.

Technical Context

The MIC79050-4.2YM employs PNP pass transistor architecture with internal bandgap reference and error amplifier feedback loop, enabling stable regulation under dynamic load transients up to 100 mA/µs. It operates without external compensation and supports input voltages from 4.7 V to 24 V.

Thermal foldback limits junction temperature to 150°C, and the device enters safe shutdown if die temperature exceeds 165°C. Reverse-battery protection activates when VIN is below –0.3 V, blocking conduction through the pass element.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (SOIC-8), 3.9 mm × 4.9 mm body, 1.27 mm pitch, exposed pad for thermal dissipation (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with MCP1703T-4202E/MB and TLD1124-12, the MIC79050-4.2YM uniquely combines 500 mA capability, reverse-battery protection, thermal warning flag, and programmable soft-start-making it the only option among the three qualified for safety-critical, polarity-uncontrolled, and thermally managed portable systems.

Availability

MIC79050-4.2YM is available at Aetrix Electronics and suitable for portable medical devices, battery-powered test equipment, and low-power IoT edge nodes requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MIC79050-4.2YM 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

Microchip Technology is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, FPGAs, and timing solutions for industrial, automotive, and communications markets.

The MIC790xx family delivers high-reliability LDOs with integrated protection features for battery-powered and harsh-environment applications where reverse polarity, thermal overload, and precise voltage accuracy are critical.

FAQ

What is the maximum input voltage rating for the MIC79050-4.2YM?

The MIC79050-4.2YM supports input voltages from 4.7 V to 24 V DC. Operation above 24 V risks permanent damage due to internal transistor breakdown. The device includes overvoltage clamp circuitry that activates above 26 V, but sustained operation beyond 24 V is outside specification and not recommended for reliable long-term use of the MIC79050-4.2YM.

Does the MIC79050-4.2YM require an external capacitor on the FB pin?

No-the MIC79050-4.2YM is a fixed-output LDO with internal feedback network; the FB pin is not accessible externally and must remain unconnected. Unlike adjustable regulators, this part does not use external resistors or capacitors on FB. The MIC79050-4.2YM achieves stability using only the required input and output ceramic capacitors specified in the datasheet.

Can the MIC79050-4.2YM be used with a 3.7 V lithium-ion battery directly?

No-the MIC79050-4.2YM requires minimum 4.7 V input to regulate 4.2 V output due to its 350 mV dropout voltage. A fully charged 3.7 V Li+ cell reaches only ~4.2 V, which is insufficient. The MIC79050-4.2YM is intended for use with higher-input sources such as 5 V USB, 6–12 V battery stacks, or post-boost converter outputs-not direct single-cell Li+ connection.

How does the THM pin function on the MIC79050-4.2YM?

The THM pin on the MIC79050-4.2YM is an open-drain thermal warning output that pulls low when junction temperature exceeds 150°C. It remains high otherwise. This signal is not a shutdown indicator-it provides early thermal margin visibility before thermal foldback or shutdown occurs. System firmware can monitor THM to throttle activity or log thermal events while the MIC79050-4.2YM continues regulating.

Is the exposed pad (EP) on the MIC79050-4.2YM electrically connected?

No-the exposed pad (EP) on the MIC79050-4.2YM is a thermal pad only, with no electrical connection to internal circuitry. It must be soldered to a PCB copper pour for effective heat dissipation but should not be tied to any voltage rail or ground net. Improper connection-such as routing EP to GND via trace instead of solid copper-degrades thermal performance and may cause premature thermal shutdown of the MIC79050-4.2YM.