Microchip Technology MIC5350-SMYMT-TR

Overview

MIC5350-SMYMT-TR from Micrel is a dual-output ultra-low-dropout linear regulator integrating independent 300mA (VOUT1 = 3.3V) and 500mA (VOUT2 = 2.8V) LDOs in an 8-pin 2mm × 2mm Thin MLF® package. It delivers ultra-low noise (30µVRMS), low dropout (75mV @ 300mA, 125mV @ 500mA), ±2% output accuracy, and stable operation with 2.2µF ceramic capacitors - ideal for powering RF sections and camera modules in space-constrained portable electronics.

For engineers reviewing the MIC5350-SMYMT-TR datasheet, MIC5350-SMYMT-TR pinout, MIC5350-SMYMT-TR application, or MIC5350-SMYMT-TR equivalent, key selection criteria include dual-rail voltage sequencing capability, thermal performance in 2mm × 2mm footprint, µCap stability with minimal external components, and independent enable control for power domain isolation in battery-powered imaging systems.

Technical Context

The MIC5350-SMYMT-TR implements two independent CMOS-based ULDO regulators with separate active-high enable inputs (EN1/EN2), allowing asynchronous startup and shutdown of each output. Its internal reference bypass (BYP pin) supports 0.1µF capacitor connection to reduce output noise by filtering reference voltage ripple.

Stability is achieved with ≥2.2µF low-ESR ceramic output capacitors per rail and a mandatory 2.2µF input capacitor; no minimum load is required. Thermal shutdown and current-limit protection are integrated, with junction-to-ambient thermal resistance θJA = 90°C/W enabling 300mA/500mA continuous operation at ambient temperatures up to 89°C under typical 3.3V input conditions.

Key Specifications

Pinout & Package

Package: 8-pin 2mm × 2mm Thin MLF® (TMLF), leadless, RoHS-compliant, NiPdAu finish, halogen-free mold compound. Exposed heatsink pad (EPAD) internally connected to GND for enhanced thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MIC5350-SMYMT-TR, both alternatives lack integrated dual-rail architecture and ultra-low-noise design - making them unsuitable for simultaneous 3.3V/2.8V RF-imaging power delivery without added components, larger PCB area, or compromised noise performance.

Availability

MIC5350-SMYMT-TR is available at Aetrix Electronics and suitable for cellular phone camera modules, GPS receivers, and portable media players requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MIC5350-SMYMT-TR 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 semiconductor company specializing in analog, power management, and timing solutions before its acquisition by Microchip Technology in 2015. Known for high-performance LDOs and Ethernet PHYs.

The MIC5350-SMYMT-TR belongs to Micrel's ULDO™ family of ultra-low-noise, ultra-low-dropout regulators designed specifically for noise-sensitive portable imaging and RF applications where board space and battery life are critical constraints.

FAQ

What are the fixed output voltages of the MIC5350-SMYMT-TR?

The MIC5350-SMYMT-TR provides fixed output voltages of 3.3V on VOUT1 (300mA rated) and 2.8V on VOUT2 (500mA rated). These values are laser-trimmed during manufacturing and cannot be adjusted externally. The part marking "FSM" on the top surface confirms this specific dual-voltage configuration, and no external feedback resistors are required or supported.

Does the MIC5350-SMYMT-TR require external capacitors, and what types are recommended?

Yes, the MIC5350-SMYMT-TR requires a 2.2µF ceramic input capacitor (X5R/X7R dielectric), two 2.2µF ceramic output capacitors (one per rail), and optionally a 0.1µF ceramic bypass capacitor on the BYP pin. X7R-type ceramics are preferred for their ±15% capacitance stability across –40°C to +125°C; Y5V/Z5U types are discouraged due to >50% drift over temperature.

Can the MIC5350-SMYMT-TR operate without any load connected to its outputs?

Yes, the MIC5350-SMYMT-TR remains stable with zero load on either or both outputs - a feature uncommon among LDOs. This makes it suitable for applications like CMOS RAM keep-alive circuits or always-on sensor biasing where one rail may be idle while the other is active, eliminating the need for dummy loads or complex load-switching schemes.

What is the thermal performance limit of the MIC5350-SMYMT-TR in a standard PCB layout?

In a standard 2-layer PCB layout with the EPAD soldered to a 1cm² internal GND plane, the MIC5350-SMYMT-TR achieves θJA = 90°C/W. At 3.3V input, 3.3V/2.8V outputs, and full 300mA/500mA load, power dissipation is ~0.4W, limiting maximum ambient temperature to ~89°C before thermal shutdown activates - sufficient for most handheld consumer applications.

How does the BYP pin function in the MIC5350-SMYMT-TR, and is it mandatory?

The BYP pin in the MIC5350-SMYMT-TR connects to the internal voltage reference node; adding a 0.1µF ceramic capacitor to GND reduces output voltage noise to 30µVRMS and improves PSRR at high frequencies. It is not mandatory for basic regulation but is strongly recommended for RF, imaging, and GPS applications where supply noise directly impacts signal integrity. Leaving BYP open degrades noise performance but maintains regulation.