Microchip Technology MIC25400YML-TR

Overview

MIC25400YML-TR from Micrel is a dual-output synchronous PWM buck regulator IC with two integrated 2A high-side N-channel MOSFETs and external low-side N-MOSFET drivers, operating at 1 MHz switching frequency, delivering adjustable output voltages down to 0.7 V with ±2% accuracy over –40°C to +125°C, used in FPGA/CPU multi-rail power supplies requiring precise sequencing.

For engineers reviewing the MIC25400YML-TR datasheet, MIC25400YML-TR pinout, MIC25400YML-TR application, or MIC25400YML-TR equivalent, key selection considerations include its 180° out-of-phase dual-channel operation, programmable current limit (0.5–2.7 A), ramp-controlled soft-start, power-good outputs for sequencing, and compatibility with ceramic output capacitors in compact 4 mm × 4 mm MLF-24L package.

Technical Context

The MIC25400YML-TR implements voltage-mode PWM control with a fixed 1 MHz oscillator driving two independent channels 180° out of phase to minimize input ripple. Each channel uses an internal high-side switch and external low-side N-MOSFET driven by dedicated LSD pins, with current sensing via low-side R_DS(ON) for accurate overcurrent protection across wide duty-cycle ranges.

It integrates a 5 V internal linear regulator (PVDD) for gate drive and analog circuitry, supports output voltage sequencing via PG-to-EN/DLY interconnection, and features adaptive dead-time control to prevent shoot-through-enabling stable operation with 4.5 V to 13.2 V input and junction temperatures up to +125°C.

Key Specifications

Pinout & Package

The MIC25400YML-TR is housed in a thermally enhanced 24-pin 4 mm × 4 mm ePad MLF® package (ML-24L), with exposed thermal pad (EP) requiring full-solder connection to PCB ground plane for optimal thermal performance (θ_JA = 35°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output synchronous buck regulator applications.

Compared with TPS54290PWPR and RT8209MZQW, the MIC25400YML-TR uniquely combines dual integrated 2 A high-side switches, external low-side drivers, 180° phase shift, and PG-based sequencing in one 4 mm × 4 mm package-reducing BOM count and PCB area while enabling robust low-duty-cycle operation.

Availability

MIC25400YML-TR is available at Aetrix Electronics and suitable for FPGA power supplies, telecom DC-DC modules, and industrial CPU boards requiring stable component supply, long-term lifecycle support, and Pb-free RoHS compliance.

Supply support for MIC25400YML-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 analog and mixed-signal semiconductor company founded in 1978 and acquired by Microchip Technology in 2015; it specialized in power management, timing, and interface ICs for industrial and communications markets.

The MIC25400YML-TR belongs to Micrel's high-efficiency synchronous buck regulator product line, designed specifically for space-constrained, multi-rail embedded systems needing precise voltage sequencing, wide input range, and thermal resilience.

FAQ

What is the maximum allowable input voltage for the MIC25400YML-TR?

The MIC25400YML-TR has an absolute maximum input voltage rating of 16 V on VIN, VIND1, and VIND2 pins. Its recommended operating input voltage range is 4.5 V to 13.2 V. Exceeding 13.2 V may cause premature UVLO release or overstress internal high-side MOSFETs; operation above 16 V risks permanent damage per Absolute Maximum Ratings.

Can the MIC25400YML-TR operate with only one output enabled?

Yes, the MIC25400YML-TR supports single-output operation: EN/DLY1 or EN/DLY2 can be held low to disable the corresponding channel independently. However, the disabled output requires a minimum 2 kΩ load to prevent voltage rise due to leakage; this can be implemented using the feedback divider resistors if their combined value meets the requirement.

What external MOSFET specifications are required for use with the MIC25400YML-TR's LSD outputs?

The MIC25400YML-TR's LSD1 and LSD2 outputs require external N-channel MOSFETs rated for ≥4.5 V gate drive (V_GS), with low R_DS(ON) and high C_GS/C_GD ratio to suppress dv/dt-induced turn-on. Micrel explicitly advises against MOSFETs rated below 4.5 V V_GS, as they increase susceptibility to false triggering during high dV/dt switching events.

How does the MIC25400YML-TR achieve output voltage sequencing between its two channels?

The MIC25400YML-TR achieves sequencing by connecting PG1 (open-drain) to EN/DLY2 through a pull-up resistor to PVDD. When VOUT1 reaches ≥90% regulation, PG1 goes high, releasing EN/DLY2 and allowing VOUT2 to start ramping. This hardware-based method eliminates need for external timers or microcontrollers and ensures deterministic startup order.

Is the MIC25400YML-TR compatible with ceramic output capacitors?

Yes, the MIC25400YML-TR is fully optimized for ceramic output capacitors, including X5R and X7R dielectrics. Its patented compensation architecture requires only one external RC network per channel and maintains stability across capacitor values from 4.7 µF to 100 µF, enabling low-ESR, high-frequency filtering without risk of oscillation.