Microchip Technology MIC5318-2.5YD5-TR

Overview

MIC5318-2.5YD5-TR from Micrel is a fixed-output 2.5V ultra-low dropout (ULDO™) linear regulator delivering 300mA output current with 110mV dropout at full load, 30µV_RMS output noise, and ±2% initial accuracy - designed for RF-sensitive portable electronics requiring stable low-noise biasing.

For engineers reviewing the MIC5318-2.5YD5-TR datasheet, MIC5318-2.5YD5-TR pinout, MIC5318-2.5YD5-TR application, or MIC5318-2.5YD5-TR equivalent, key selection criteria include its 5-pin Thin SOT23 package, enable-controlled zero-off-mode (1µA shutdown current), PSRR >70dB at 1kHz, and compatibility with 1µF ceramic output capacitors without external compensation.

Technical Context

The MIC5318-2.5YD5-TR implements a CMOS-based LDO architecture with integrated error amplifier, thermal shutdown, and current limiting. Its quick-start bypass circuit enables stable operation with a 0.01µF reference bypass capacitor while maintaining <35µs turn-on time.

It operates across 2.3V–6.0V input range and supports –40°C to +125°C junction temperature. The device achieves high PSRR via internal feedback loop optimization and low-noise performance through dedicated BYP pin filtering of the bandgap reference.

Key Specifications

Pinout & Package

Package: 5-Pin Thin SOT23 (D5), 2.9mm × 1.6mm footprint, exposed pad internally connected to GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-noise LDO regulator applications.

Compared with MCP1700-2502E/TO and XC6206P252MR-G, the MIC5318-2.5YD5-TR delivers superior 300mA capability, lowest dropout (110mV), and integrated enable - making it optimal for RF-critical, battery-constrained designs where every millivolt and microamp matters.

Availability

MIC5318-2.5YD5-TR is available at Aetrix Electronics and suitable for mobile phones, GPS receivers, digital still cameras, and Bluetooth LE audio modules requiring stable component supply with guaranteed long-term availability.

Supply support for MIC5318-2.5YD5-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 high-performance analog, power management, and timing solutions before its acquisition by Microchip Technology in 2015.

The MIC5318 product line was developed for ultra-low-noise, ultra-low-dropout regulation in space- and power-constrained portable RF systems - emphasizing ceramic capacitor compatibility, zero-off-mode, and miniature packaging.

FAQ

What is the maximum input voltage rating for the MIC5318-2.5YD5-TR?

The MIC5318-2.5YD5-TR has an absolute maximum input voltage of +6.5V, but its specified operating input range is +2.3V to +6.0V. Exceeding 6.0V may cause permanent damage even if within the absolute maximum rating, as internal protection circuits are not guaranteed beyond operational limits. Always design with 6.0V as the functional upper bound for MIC5318-2.5YD5-TR.

Does the MIC5318-2.5YD5-TR require an external bypass capacitor on the BYP pin?

The MIC5318-2.5YD5-TR does not require the BYP pin to be used, but connecting a 0.01µF capacitor from BYP to GND reduces output noise to 30µV_RMS. Without it, noise increases significantly. The BYP pin may be left open only if noise performance is not critical; however, for RF or precision analog applications, the 0.01µF capacitor is strongly recommended for MIC5318-2.5YD5-TR.

Can the MIC5318-2.5YD5-TR remain stable with no load connected?

Yes, the MIC5318-2.5YD5-TR remains stable and in regulation with zero load current - a feature explicitly confirmed in its application notes. This makes it suitable for CMOS RAM keep-alive, real-time clock backup, or other always-on low-power subsystems where load current may drop to zero intermittently. No minimum load resistor is required for MIC5318-2.5YD5-TR operation.

What is the thermal resistance (θ_JA) of the MIC5318-2.5YD5-TR in its SOT23-5 package?

The MIC5318-2.5YD5-TR has a junction-to-ambient thermal resistance (θ_JA) of 235°C/W in the 5-pin Thin SOT23 (D5) package, as specified in the official datasheet. This value assumes standard JEDEC 2-layer board conditions. Layout improvements - such as increased copper area connected to the exposed pad - can reduce effective θ_JA, but 235°C/W is the baseline for thermal design calculations involving MIC5318-2.5YD5-TR.

Is the MIC5318-2.5YD5-TR RoHS compliant and lead-free?

Yes, the MIC5318-2.5YD5-TR is RoHS compliant and manufactured in a lead-free process, as confirmed in the ordering information and general description sections of the official Micrel datasheet. The "-TR" suffix denotes tape-and-reel packaging, and all MIC5318 variants in Thin MLF® and Thin SOT23-5 packages meet RoHS Directive 2011/65/EU requirements. MIC5318-2.5YD5-TR contains no intentionally added lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE.