Microchip Technology MIC5265-1.85YD5

Overview

MIC5265-1.85YD5 from Micrel is a 150mA low-dropout linear regulator in Pb-Free Thin SOT-23-5 packaging, delivering fixed 1.85V 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 MIC5265-1.85YD5 datasheet, MIC5265-1.85YD5 pinout, MIC5265-1.85YD5 application, or MIC5265-1.85YD5 equivalent, key selection criteria include its active shutdown discharge capability, ceramic-capacitor stability (≥1µF), and enable-input compatibility with CMOS logic levels (V_IL ≤ 0.2V, V_IH ≥ 1.6V).

Technical Context

The MIC5265-1.85YD5 integrates a precision bandgap reference, error amplifier, and NMOS pass transistor with active shutdown clamp. Its quick-start bypass circuit enables fast turn-on even with 0.01–1.0µF BYP capacitors, while internal thermal shutdown (150°C) and current limiting (225mA) ensure robust operation under fault conditions.

It operates across 2.7–5.5V input range-compatible with single-cell Li-ion (3.0–4.2V), 3.3V, or 5V rails-and maintains regulation down to zero load. The EN pin provides CMOS-compatible active-high control, forcing the device into sub-2µA off-state current when pulled low.

Key Specifications

Pinout & Package

Pb-Free Thin SOT-23-5 (M5) package: 2.9mm × 1.6mm × 1.1mm body, 0.95mm pitch, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1802E/TT and XC6206P182MR-G, the MIC5265-1.85YD5 uniquely combines RF-grade noise performance (57µV_rms), active output discharge, and dual-pin control (EN + BYP) in a 150mA SOT-23-5 footprint-making it optimal for compact, multi-rail portable designs demanding both efficiency and signal integrity.

Availability

MIC5265-1.85YD5 is available at Aetrix Electronics and suitable for cellular telephones, GPS receivers, and portable digital audio systems requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for MIC5265-1.85YD5 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 for cost-sensitive, space-constrained portable electronics requiring high PSRR, low noise, and fast transient response-targeting RF and digital subsystems powered from single-cell batteries.

FAQ

What is the maximum input voltage rating for the MIC5265-1.85YD5?

The MIC5265-1.85YD5 has an absolute maximum input voltage of +7V, but its recommended operating range is +2.7V to +5.5V. Exceeding 5.5V risks violating functional specifications and may trigger thermal shutdown. For reliable operation with a 5V system rail, the MIC5265-1.85YD5 provides 210mV dropout headroom and remains within safe junction temperature limits when properly heatsinked.

Does the MIC5265-1.85YD5 require an external bypass capacitor, and what value is recommended?

Yes, the MIC5265-1.85YD5 requires an external capacitor on the BYP pin to achieve specified noise and PSRR performance. A 0.01µF ceramic capacitor is recommended for general low-noise applications; values up to 1.0µF further reduce output noise and improve PSRR at higher frequencies, though turn-on time increases slightly. The BYP pin may be left open if noise performance is not critical, but 57µV_rms noise and 60dB PSRR are only guaranteed with 0.01µF.

How does the active shutdown feature of the MIC5265-1.85YD5 function during disable?

When the EN pin is pulled low, the MIC5265-1.85YD5 enters zero-current shutdown and activates an internal N-channel MOSFET between OUT and GND. This discharge path rapidly de-energizes the output capacitor and downstream load-preventing unintended biasing or latch-up in RF front-ends or memory retention circuits. The discharge resistance is 500Ω, ensuring controlled ramp-down without excessive inrush current.

Can the MIC5265-1.85YD5 operate stably with zero load current?

Yes, the MIC5265-1.85YD5 remains stable and in regulation with no load, unlike many LDOs that require minimum load current. This capability is essential for applications such as CMOS RAM keep-alive circuits, real-time clock backup supplies, or sensor nodes in deep-sleep mode. The device maintains 1.85V output accuracy within ±3% across the full –40°C to +125°C junction temperature range, even at 0mA load.

What output capacitor type and value are required for stability with the MIC5265-1.85YD5?

The MIC5265-1.85YD5 requires a minimum 1µF ceramic output capacitor with ESR ≤ 300mΩ for guaranteed stability. X7R or X5R dielectric types are recommended due to their stable capacitance over temperature (±15%); Y5V or Z5U types are discouraged due to >50% capacitance drift. Larger values (e.g., 2.2µF) are acceptable but provide no significant performance gain beyond the optimized 1µF baseline.