Microchip Technology MIC5308-1.2YMT-TR

Overview

MIC5308-1.2YMT-TR from Micrel is a fixed 1.2V, 150mA ultra-low dropout linear regulator with 45mV dropout at full load, 23µA ground current under full load, and 90dB PSRR at 1kHz - designed for low-voltage battery-powered digital loads such as GPS receivers and mobile phones.

For engineers reviewing the MIC5308-1.2YMT-TR datasheet, MIC5308-1.2YMT-TR pinout, MIC5308-1.2YMT-TR application, or MIC5308-1.2YMT-TR equivalent, key selection criteria include bias-input architecture, dual-supply operation (VIN + VBIAS), ultra-low IQ in shutdown (<2µA), stability with 1µF ceramic output capacitor, and thermal performance in the 1.6mm × 1.6mm Thin MLF® package.

Technical Context

The MIC5308-1.2YMT-TR employs a dual-rail architecture: VIN supplies power to the pass element while VBIAS (2.5–5.5V) powers the control circuitry, enabling ultra-low dropout (45mV @ 150mA) even when VIN is as low as 1.6V. It uses CMOS-based enable logic with active-high EN pin and integrates thermal shutdown and current limiting.

Its internal reference voltage is 0.775V ±15mV, supporting fixed 1.2V output via internal resistor divider. The BYP/ADJ pin accepts a 10nF bypass capacitor to reduce output noise and improve PSRR - achieving up to 90dB at 1kHz with CBYP = 10nF and COUT = 1µF.

Key Specifications

Pinout & Package

Package: 6-pin 1.6mm × 1.6mm Thin MLF® (MT), RoHS-compliant, NiPdAu lead finish, halogen-free mold compound, exposed EPAD internally connected to GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with MCP1801T-1202E/MB and TCS2101-1.2V, the MIC5308-1.2YMT-TR delivers superior dropout performance (45mV vs. ≥120mV) and higher PSRR (90dB vs. ≤65dB), making it optimal for noise-sensitive, low-input-voltage applications where VBIAS is available - but requires an additional bias rail and layout coordination.

Availability

MIC5308-1.2YMT-TR is available at Aetrix Electronics and suitable for GPS receivers, portable medical sensors, PDAs, and mobile phones requiring stable component supply across extended temperature ranges (–40°C to +125°C).

Supply support for MIC5308-1.2YMT-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.

The MIC5308 family was developed for ultra-low-power, low-voltage portable electronics - specifically targeting battery-operated systems needing high PSRR, minimal dropout, and nanoscale packaging without sacrificing protection features.

FAQ

What is the dropout voltage specification for MIC5308-1.2YMT-TR?

The MIC5308-1.2YMT-TR has a typical dropout voltage of 45mV at 150mA output current and 25°C junction temperature. This value increases with temperature and load, reaching up to 150mV maximum across –40°C to +125°C. The low dropout enables operation from input voltages as low as 1.245V while maintaining 1.2V regulation - critical for extending battery life in single-cell systems.

Does MIC5308-1.2YMT-TR require an external bypass capacitor?

Yes, MIC5308-1.2YMT-TR requires a 10nF ceramic capacitor between the BYP/ADJ pin and GND to achieve its specified 90dB PSRR at 1kHz. Without this capacitor, PSRR drops to 70dB. The BYP pin is internally connected to the reference circuit; adding the capacitor reduces output voltage noise and improves ripple rejection, especially against high-frequency switching noise from upstream DC-DC converters.

What are the input voltage requirements for MIC5308-1.2YMT-TR?

MIC5308-1.2YMT-TR requires two separate input supplies: VIN must be between 1.6V and VBIAS, and VBIAS must be between 2.5V and 5.5V. VIN powers the pass element; VBIAS powers the control circuitry. This dual-rail architecture enables ultra-low dropout and high PSRR. Both rails must be properly bypassed - 1µF on VIN and 1µF on VBIAS - to ensure stability and transient performance.

Can MIC5308-1.2YMT-TR operate without a minimum load current?

Yes, MIC5308-1.2YMT-TR does not require a minimum load current to maintain regulation - unlike many older LDOs. Its internal design ensures stable 1.2V output even at zero load, which simplifies system design for intermittent-use peripherals like wake-up timers or event-triggered sensors. This eliminates the need for dummy loads or pull-down resistors that would otherwise waste battery energy.

What package type and thermal characteristics apply to MIC5308-1.2YMT-TR?

MIC5308-1.2YMT-TR uses the 6-pin 1.6mm × 1.6mm Thin MLF® (MT) package with an exposed thermal pad (EPAD) internally connected to GND. Its junction-to-ambient thermal resistance (θJA) is 90°C/W. At 150mA and 2.1V dropout (e.g., VIN = 3.3V, VOUT = 1.2V), power dissipation is ~0.315W, resulting in ~28°C rise above ambient - well within safe operating limits at +85°C ambient.