Microchip Technology MIC5399-GMYMT-T5

Overview

MIC5399-GMYMT-T5 from Microchip Technology is a dual low-dropout linear regulator (LDO) delivering two independent 300 mA outputs at fixed 1.8 V and 2.8 V, with ±2% output accuracy, 160 mV dropout at full load, and operation across 2.5–5.5 V input range. It integrates output discharge circuitry and internal enable pull-down resistors for robust power sequencing in space-constrained portable electronics.

For engineers reviewing the MIC5399-GMYMT-T5 datasheet, MIC5399-GMYMT-T5 pinout, MIC5399-GMYMT-T5 application, or MIC5399-GMYMT-T5 equivalent, key selection criteria include dual-output voltage pairing, auto-discharge capability during shutdown, thermal performance in 1.6 mm × 1.2 mm Extra Thin DFN, and compatibility with 1 µF ceramic output capacitors without stability compromise.

Technical Context

The MIC5399-GMYMT-T5 implements two fully independent LDO regulators sharing only ground and package-each with dedicated VIN, VOUT, and EN pins. Its architecture supports independent power inputs, enabling optimized supply routing per rail (e.g., separate battery and PMIC sources), and includes CMOS-based enable logic with internal 4 MΩ pull-down on both EN1 and EN2 to guarantee disable state under tri-state control.

Thermal protection and current limiting are implemented per channel, with junction temperature rated from –40°C to +125°C. The device achieves 60 dB PSRR at 1 kHz and maintains stability with no-load conditions-critical for intermittent-power systems like sensor nodes and standby subsystems.

Key Specifications

Pinout & Package

Package: 8-lead Extra Thin DFN (X2DFN), 1.6 mm × 1.2 mm × 0.35 mm body, exposed thermal pad (ePad) connected to GND. RoHS-compliant, Pb-free matte tin finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC5397-GPYMT-T5, MIC5399-GMYMT-T5 provides tighter voltage matching to legacy 2.8 V logic families and eliminates external pull-down components. Against MIC5399-GMYMX-T5, it shares identical functionality but uses the slightly thicker UDFN package-suitable where reflow profile or mechanical clearance constraints favor the standard thin variant.

Availability

MIC5399-GMYMT-T5 is available at Aetrix Electronics and suitable for smartphones, portable medical sensors, digital still cameras, and wearable fitness trackers requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for MIC5399-GMYMT-T5 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

Microchip Technology Inc. is a leading provider of microcontrollers, analog devices, FPGAs, and timing solutions, serving automotive, industrial, communications, and consumer markets with vertically integrated silicon and software platforms.

The MIC539x family was designed specifically for ultra-compact, battery-powered portable electronics requiring dual independent LDOs with minimal quiescent current, fast transient response, and integrated power sequencing features.

FAQ

What output voltages does the MIC5399-GMYMT-T5 provide?

The MIC5399-GMYMT-T5 delivers fixed, factory-trimmed output voltages of 1.8 V on VOUT1 and 2.8 V on VOUT2. These values are encoded in the part number "GM" (1.8 V/2.8 V) and are not adjustable. Both outputs maintain ±2% accuracy across –40°C to +125°C operating temperature and full load range, making MIC5399-GMYMT-T5 suitable for precision logic and analog supply applications.

Does the MIC5399-GMYMT-T5 require external pull-down resistors on its enable pins?

No, the MIC5399-GMYMT-T5 includes internal 4 MΩ pull-down resistors on both EN1 and EN2 pins, ensuring the outputs remain disabled when the enable signals are left floating or driven to high-impedance states. This eliminates the need for external pull-down components and simplifies power sequencing design-especially valuable in systems using GPIOs that may float during reset. The MIC5399-GMYMT-T5 behavior is explicitly confirmed in Section 4.4 of the datasheet.

How does the output discharge feature work on the MIC5399-GMYMT-T5?

When either EN1 or EN2 is driven low, the corresponding VOUT pin connects internally to a 25 Ω NFET discharge path to ground, rapidly draining stored charge from the output capacitor. This prevents back-powering of upstream circuitry, avoids latch-up in multi-rail systems, and ensures clean power-down sequencing. The discharge function is inherent to the MIC5399-GMYMT-T5 variant and is documented in Table 3-1 and Section 4.4 of the datasheet.

Can the MIC5399-GMYMT-T5 operate with only 1 µF output capacitors?

Yes-the MIC5399-GMYMT-T5 is fully stable with 1 µF ceramic output capacitors on both VOUT1 and VOUT2, as verified in Electrical Characteristics and Application Information sections. X5R or X7R dielectrics are recommended for optimal temperature stability. Larger capacitances do not improve performance significantly, and high-ESR types (e.g., Y5V) are discouraged due to capacitance loss over temperature. This 1 µF requirement directly reduces bill-of-materials cost and PCB area for MIC5399-GMYMT-T5 implementations.

What is the thermal resistance and maximum ambient temperature for the MIC5399-GMYMT-T5 in typical operation?

The MIC5399-GMYMT-T5 in its 8-lead UDFN package has a junction-to-ambient thermal resistance (θJA) of 172.6°C/W. Under typical conditions-3.6 V input, 300 mA per output, and 1.8 V/2.8 V outputs-the calculated power dissipation is 0.33 W. Using Equation 4-3 from the datasheet, this yields a maximum ambient operating temperature of 68.0°C before reaching the +125°C junction limit. Adequate PCB copper area and thermal vias under the ePad are essential to achieve this rating for MIC5399-GMYMT-T5.