Microchip Technology MIC5265-2.9YD5-TR

Overview

MIC5265-2.9YD5 from Micrel is a 150mA low-dropout linear regulator in Pb-Free Thin SOT-23-5 packaging, delivering fixed 2.9V output with 210mV dropout at full load, 57µV_rms output noise, and 60dB PSRR at 1kHz. It serves as a clean, low-noise power source for RF receiver stages and digital baseband circuitry in portable battery-powered systems.

For engineers reviewing the MIC5265-2.9YD5 datasheet, MIC5265-2.9YD5 pinout, MIC5265-2.9YD5 application, or MIC5265-2.9YD5 equivalent, key selection criteria include its active shutdown discharge capability, compatibility with 0.01µF bypass capacitor for noise reduction, stable operation with ceramic output capacitors ≥1µF, and enable-input logic thresholds (1.6V high / 0.2V low) for reliable control in mixed-signal environments.

Technical Context

The MIC5265-2.9YD5 integrates a CMOS-based error amplifier, quick-start reference bypass circuitry, and an N-channel active-shutdown MOSFET on the output path. Its internal architecture enables fast transient response (<150µs turn-on time) and zero off-mode current (≤2µA shutdown quiescent current).

It operates across 2.7V–5.5V input range, supports 100µA–150mA load currents, and maintains regulation down to no-load conditions-critical for CMOS RAM keep-alive and intermittent-power applications where ground current remains ≤80µA even at 150mA output.

Key Specifications

Pinout & Package

Pb-Free Thin SOT-23-5 (M5) package: 2.9mm × 1.6mm × 1.1mm body, 0.95mm pitch, gull-wing leads. RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-2902E/TO and XC6206P292MR-G, the MIC5265-2.9YD5 uniquely combines low-noise operation (57µV_rms), active output discharge, and a dedicated bypass pin-making it irreplaceable in RF and sequenced portable electronics where supply integrity and controlled shutdown are mandatory.

Availability

MIC5265-2.9YD5 is available at Aetrix Electronics and suitable for cellular telephones, GPS receivers, PDAs, and portable medical sensor nodes requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MIC5265-2.9YD5 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.

The MIC5265 family was designed specifically for cost-sensitive, space-constrained portable electronics requiring low-noise, low-quiescent-current LDO regulation with robust enable control and active shutdown-targeting RF, GPS, and handheld computing applications.

FAQ

What is the maximum input voltage rating for the MIC5265-2.9YD5?

The MIC5265-2.9YD5 has an absolute maximum input voltage rating of +7V, but its specified operating input range is +2.7V to +5.5V. Exceeding 5.5V may cause permanent damage or violate thermal limits-even if below 7V-due to increased power dissipation. For reliable operation in single-cell Li-ion systems, VIN should remain ≤5.5V, with headroom above 2.9V to maintain regulation under load.

Does the MIC5265-2.9YD5 require an external bypass capacitor on the BYP pin?

The MIC5265-2.9YD5 does not require-but strongly benefits from-a 0.01µF capacitor on the BYP pin to ground. This capacitor reduces internal reference noise, lowering total output noise from ~120µV_rms to 57µV_rms and improving PSRR by up to 10dB at 1kHz. Leaving BYP open is electrically valid but forfeits the low-noise advantage critical for RF and precision analog applications.

Can the MIC5265-2.9YD5 operate without any load connected to its output?

Yes, the MIC5265-2.9YD5 remains stable and maintains regulation with zero load current-a feature confirmed in its Applications Information section. This no-load stability is essential for applications like CMOS RAM keep-alive circuits or always-on sensor biasing, where the regulator must hold 2.9V even when downstream circuitry is powered off or disconnected.

What is the purpose of the active shutdown function in the MIC5265-2.9YD5?

When the EN pin is pulled low, the MIC5265-2.9YD5 activates an internal 500Ω N-channel MOSFET between OUT and GND. This active discharge path rapidly depletes stored charge on the output capacitor and load, ensuring the output falls to near-zero volts within milliseconds. This prevents back-powering, avoids latch-up in downstream ICs, and enables precise power sequencing in multi-rail systems.

Is the MIC5265-2.9YD5 compatible with ceramic output capacitors?

Yes, the MIC5265-2.9YD5 is fully optimized for ceramic output capacitors: it requires ≥1µF X7R or X5R dielectric type (ESR ≤300mΩ) and remains stable across temperature and aging. Unlike many older LDOs, it does not require high-ESR tantalum or aluminum electrolytic capacitors-enabling smaller footprint, lower cost, and improved reliability in portable designs.