Microchip Technology MIC5303-1.8YMT-TR

Overview

MIC5303-1.8YMT-TR from Micrel is a fixed-output 1.8V, 300mA ultra-low dropout CMOS LDO regulator in a 4-pin 1.2mm × 1.6mm Thin MLF® package. It delivers 2% initial output accuracy, 100mV dropout at full load, and 120µV_RMS output noise-optimized for RF power stages in cellular handsets and camera modules where board space and low-noise biasing are critical.

For engineers reviewing the MIC5303-1.8YMT-TR datasheet, MIC5303-1.8YMT-TR pinout, MIC5303-1.8YMT-TR application, or MIC5303-1.8YMT-TR equivalent, key selection criteria include its 85µA quiescent current, –40°C to +125°C operating junction range, enable-controlled zero-off-mode, and ceramic-capacitor stability with only 1µF required on input and output.

Technical Context

The MIC5303-1.8YMT-TR integrates a CMOS pass element with error amplifier, thermal shutdown, and current limit circuitry in a single-die architecture. Its active-high enable (EN) pin directly controls regulator state without external pull-up, and the internal ground-current path remains stable across 0–300mA load while maintaining <2% output voltage deviation over temperature.

Designed for high-bandwidth, low-noise operation, it achieves 65dB PSRR up to 1kHz and maintains stability with 1µF X7R ceramic capacitors on both input and output-eliminating need for tantalum or electrolytic types. The exposed pad (EPAD) is internally connected to GND, providing thermal conduction and EMI shielding in compact RF layouts.

Key Specifications

Pinout & Package

Package: 4-pin 1.2mm × 1.6mm Thin MLF® (MT) with exposed thermal pad (EPAD) internally tied to GND. Occupies only 1.92mm² PCB area-50% smaller than SC-70 and 2mm × 2mm MLF® alternatives.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1801T-1802E/MB and XC6206P182MR-G, the MIC5303-1.8YMT-TR provides 300mA output, 100mV dropout, integrated enable, and 50% smaller footprint-making it optimal for space-constrained, high-performance portable RF and imaging systems requiring precise 1.8V biasing.

Availability

MIC5303-1.8YMT-TR is available at Aetrix Electronics and suitable for cellular phone RF power stages, digital camera image sensor biasing, and portable media player audio codec supply requiring stable component supply, RoHS-compliant packaging, and extended temperature support.

Supply support for MIC5303-1.8YMT-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. It pioneered high-performance, ultra-small LDOs for portable electronics.

The MIC5303 product line was designed specifically for space-constrained, noise-sensitive portable applications-including cellular RF, camera modules, and PMPs-where ultra-low dropout, minimal PCB area, and ceramic-capacitor compatibility were essential.

FAQ

What is the maximum input voltage rating for the MIC5303-1.8YMT-TR?

The MIC5303-1.8YMT-TR has an absolute maximum input voltage rating of +6V. However, its specified operating input range is +2.3V to +5.5V. Exceeding 5.5V may cause permanent damage or violate functional specifications-even if below the 6V absolute maximum-so design margins should respect the 5.5V operational limit.

Does the MIC5303-1.8YMT-TR require an external pull-up resistor on the EN pin?

No, the MIC5303-1.8YMT-TR does not require an external pull-up resistor on the EN pin. Its enable input uses CMOS logic with defined thresholds (V_IL ≤ 0.2V, V_IH ≥ 1.1V), and the pin must be actively driven high or low-never left floating-to avoid indeterminate output behavior. Direct connection to a 1.8V GPIO is sufficient.

Can the MIC5303-1.8YMT-TR operate stably with no load?

Yes, the MIC5303-1.8YMT-TR remains stable and in regulation with zero load current-a key differentiator from many LDOs. This feature is explicitly verified and supports applications like CMOS RAM keep-alive circuits or always-on sensor bias rails where load current may drop to zero between activity cycles.

What ceramic capacitor dielectric is recommended for use with the MIC5303-1.8YMT-TR?

X7R dielectric ceramic capacitors are recommended for both input and output of the MIC5303-1.8YMT-TR. They provide stable capacitance (±15% over –55°C to +125°C), low ESR, and reliable performance. Y5V or Z5U types are discouraged due to >50% capacitance loss over temperature, which risks instability at extremes.

Is the exposed pad (EPAD) on the MIC5303-1.8YMT-TR electrically connected, and how should it be handled?

Yes, the EPAD on the MIC5303-1.8YMT-TR is internally connected to GND. It must be soldered to a PCB thermal pad tied to the system ground plane to ensure proper thermal dissipation and EMI suppression. Leaving it unconnected degrades thermal performance and may increase output noise or trigger premature thermal shutdown under load.