Microchip Technology MIC5265-3.3YD5

Overview

MIC5265-3.3YD5 from Micrel is a 150mA low-dropout linear regulator in Pb-Free Thin SOT-23-5 packaging, delivering fixed 3.3V 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 receivers and digital baseband circuits in portable battery-powered systems.

For engineers reviewing the MIC5265-3.3YD5 datasheet, MIC5265-3.3YD5 pinout, MIC5265-3.3YD5 application, or MIC5265-3.3YD5 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 MIC5265-3.3YD5 integrates a CMOS-based error amplifier, reference voltage generator with quick-start noise cancellation, thermal shutdown (150°C), and an active N-channel MOSFET discharge circuit on the output. Its architecture supports fast transient response (<150µs turn-on time) and maintains regulation down to zero load.

It operates across 2.7V–5.5V input range-enabling direct use with single-cell Li-ion (3.0–4.2V) or fixed 3.3V/5V rails-and features internally trimmed output voltage accuracy (±2% over temperature), low ground current (75–150µA), and thermal resistance θ_JA = 235°C/W in the Thin SOT-23-5 package.

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, JEDEC MO-178AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-3302E/TO and TCS2103-3.3, the MIC5265-3.3YD5 offers balanced performance: superior PSRR (60dB vs ≤55dB), integrated active discharge, and proven stability with minimal external components-making it optimal for RF-critical and battery-constrained designs requiring both precision and controllability.

Availability

MIC5265-3.3YD5 is available at Aetrix Electronics and suitable for cellular telephones, GPS receivers, PDAs, and portable medical sensors requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MIC5265-3.3YD5 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 MIC5265 family was designed specifically for cost-sensitive, space-constrained portable electronics needing low-noise, low-IQ, and fast-response regulation-targeting RF front-ends and digital baseband subsystems in handheld wireless devices.

FAQ

What is the maximum input voltage rating for the MIC5265-3.3YD5?

The MIC5265-3.3YD5 has an absolute maximum input voltage of +7V, but its recommended operating range is +2.7V to +5.5V. Exceeding 5.5V may trigger internal protection or cause reliability issues. For single-cell Li-ion applications, this range accommodates full charge (4.2V) and discharge (3.0V) profiles while maintaining regulation at 3.3V output. Always observe derating guidelines per thermal calculations in the MIC5265-3.3YD5 datasheet.

Does the MIC5265-3.3YD5 require an external bypass capacitor, and what value is recommended?

Yes, the MIC5265-3.3YD5 requires an external capacitor on the BYP pin to optimize noise and PSRR. A 0.01µF ceramic capacitor (X7R/NPO) to GND is recommended for standard low-noise operation. Larger values up to 1µF further reduce output noise and improve PSRR at higher frequencies, though turn-on time increases slightly. The MIC5265-3.3YD5 includes a quick-start circuit to mitigate delay penalties from larger BYP caps.

Can the MIC5265-3.3YD5 remain stable with no load connected to its output?

Yes, the MIC5265-3.3YD5 is explicitly characterized for no-load stability and maintains regulation without requiring minimum load current. This behavior is confirmed in the Applications Information section and typical characteristics plots. It is especially valuable in CMOS RAM keep-alive circuits, real-time clock backups, and sensor wake-up paths where the load may be disconnected for extended periods while the MIC5265-3.3YD5 remains powered and enabled.

What is the purpose of the active shutdown feature in the MIC5265-3.3YD5?

The active shutdown feature in the MIC5265-3.3YD5 uses an internal N-channel MOSFET to actively discharge the output capacitor and load when the EN pin is driven low. Unlike passive leakage discharge, this ensures rapid, controlled de-energization-critical for preventing residual voltage from interfering with downstream reset sequencing or causing latch-up in powered-off sections. This function is documented in the Block Diagram and Applications Information sections of the MIC5265-3.3YD5 datasheet.

Is the MIC5265-3.3YD5 compatible with ceramic output capacitors, and what ESR range is supported?

Yes, the MIC5265-3.3YD5 is optimized for ceramic output capacitors with values ≥1µF and ESR ≤300mΩ. X7R or X5R dielectrics are recommended for temperature stability; Z5U and Y5V types are discouraged due to large capacitance drift. The device remains stable across the full ESR range and does not require series resistance for compensation-reducing BOM count and board area versus older LDOs requiring tantalum or aluminum electrolytics.