Microchip Technology MIC24085EYML-TX

Overview

MIC24085EYML-TX from Micrel is a fixed 3.3V, 3A synchronous buck regulator with integrated high- and low-side MOSFETs, operating at 1MHz switching frequency over 4.5V–18V input range. It delivers regulated power in space-constrained networking and embedded systems, featuring 0.9V reference accuracy (±1.5%), 10µA shutdown current, and thermal/overcurrent protection.

For engineers reviewing the MIC24085EYML-TX datasheet, MIC24085EYML-TX pinout, MIC24085EYML-TX application, or MIC24085EYML-TX equivalent, key selection considerations include its 3.3V fixed output, 16-pin 3mm × 3mm QFN package, PFM light-load mode, internal soft-start (4ms), and power-good monitoring with 93–103% output voltage window.

Technical Context

The MIC24085EYML-TX implements peak current-mode PWM control with internal slope compensation and fully integrated loop compensation-enabling stable operation with low-ESR ceramic output capacitors. Its cycle-by-cycle current limit triggers frequency foldback to 250kHz when feedback drops below 60% of 0.9V, reducing average inductor current during overload.

It integrates dual N-channel MOSFETs (135mΩ high-side, 90mΩ low-side), supports enable-controlled startup with hysteresis (EN threshold: 2.2V high / 0.8V low), and provides open-drain power-good output with 11ms recovery hold time after fault clearance.

Key Specifications

Pinout & Package

Package: 16-pin, 3mm × 3mm QFN (ML) with exposed thermal pad (ePAD), rated for –40°C to +125°C junction temperature. Pin 1 marked by dot; ePAD must be soldered to PGND for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output buck regulator applications.

Compared with MP2333HG-33-P and TPS54332DDA, the MIC24085EYML-TX offers plug-and-play 3.3V regulation with integrated PG, OVP, and thermal protection-reducing validation effort and component count in cost-sensitive, volume production of fixed-rail systems.

Availability

MIC24085EYML-TX is available at Aetrix Electronics and suitable for networking infrastructure, embedded gateways, and industrial camera modules requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MIC24085EYML-TX 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

Micrel Inc. was a U.S.-based analog and power IC manufacturer, acquired by Microchip Technology in 2015; its legacy buck regulators remain widely deployed in industrial and telecom applications.

The MIC24085 product line delivers highly integrated, cost-optimized DC-DC solutions for space-constrained, high-current applications where simplicity, reliability, and thermal robustness are critical.

FAQ

What is the output voltage tolerance of the MIC24085EYML-TX over temperature?

The MIC24085EYML-TX provides a fixed 3.3V output with ±1.5% accuracy across its full operating junction temperature range of –40°C to +125°C. This specification derives directly from the 0.9V internal reference voltage tolerance (±1.5%) and the factory-trimmed resistor divider used to set 3.3V, as confirmed in the Electrical Characteristics table on page 4 of the official datasheet.

Does the MIC24085EYML-TX require external feedback resistors?

No, the MIC24085EYML-TX does not require external feedback resistors. As a fixed 3.3V variant, its output voltage is internally set; the FB pin is unused and must be left floating or bypassed per datasheet guidance. This eliminates resistor matching errors and reduces bill-of-materials count compared to adjustable versions like MIC24085AYML.

How does the power-good (PG) signal behave during startup and fault conditions?

The MIC24085EYML-TX asserts PG high only when the output reaches and sustains 93–103% of 3.3V. During startup, PG remains low until regulation is achieved and held for ≥11ms. If VOUT drops below 93% due to overload or short, PG pulls low immediately and stays low for 11ms after recovery before reasserting high-ensuring clean system reset sequencing.

What thermal performance can be expected from the MIC24085EYML-TX in a standard 2-layer PCB layout?

In a standard 2-layer PCB with 1oz copper and the ePAD fully soldered to a 1cm² PGND pour, the MIC24085EYML-TX achieves θJA ≈ 68°C/W. At 3A load and 12V input, junction temperature rise is approximately 60°C above ambient-well within the –40°C to +125°C rating. Thermal shutdown activates only if layout or airflow limits heat dissipation beyond this baseline.

Is the MIC24085EYML-TX RoHS-compliant and halogen-free?

Yes, the MIC24085EYML-TX is Pb-free and RoHS-compliant, as indicated by the "Pb-Free" designation in the Ordering Information table and confirmed in Micrel's packaging documentation. The 16-pin QFN (ML) package uses matte tin lead finish and meets JEDEC MSL3 moisture sensitivity requirements.