Analog Devices Inc./Maxim Integrated MAX42406AFOA+

Overview

MAX42406AFOA+ from Analog Devices is a fully integrated 36V, 6A synchronous buck converter with internal high-side and low-side MOSFETs, fixed 1.5MHz switching frequency, programmable 0.8V–10V output voltage, and PGOOD monitoring-designed for industrial point-of-load regulation in space-constrained systems.

For engineers reviewing the MAX42406AFOA+ datasheet, MAX42406AFOA+ pinout, MAX42406AFOA+ application, or MAX42406AFOA+ equivalent, key selection factors include its 17-pin FC2QFN package, dual-phase capability via VEA/SYNCOUT, 20μA no-load quiescent current in skip mode, and dropout operation up to 96% duty cycle.

Technical Context

The MAX42406AFOA+ implements average current-mode control with internal slope compensation, enabling robust noise immunity and precise dynamic current sharing in dual-phase configurations. It supports forced-PWM or automatic skip-mode operation via the SYNC pin and features an internal 1.8V BIAS regulator with switchover from input to output during startup.

Its architecture includes a 36ns minimum on-time for high step-down ratios, integrated overtemperature and short-circuit protection with hiccup mode, and symmetrical FC2QFN pinout optimized for EMI reduction through balanced VIN/PGND routing and dual-SUP capacitor placement.

Key Specifications

Pinout & Package

MAX42406AFOA+ is housed in a 3.5mm × 3.75mm, 17-pin flip-chip quad flat no-lead (FC2QFN) package with exposed thermal pad, optimized for low EMI and high thermal performance in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with MAX42405AFOA+, the MAX42406AFOA+ delivers 20% higher continuous current and tighter current-limit threshold tolerance (±12.5% vs ±15%), enabling more robust overload handling in motor-control feedback loops; versus MP2451DT-LF-Z, it replaces ≥8 discrete components while adding diagnostics, dual-phase scalability, and industrial-grade thermal protection.

Availability

MAX42406AFOA+ is available at Aetrix Electronics and suitable for industrial automation, point-of-load regulation, and distributed DC power systems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX42406AFOA+ 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The MAX42405/MAX42406 family was engineered specifically for high-density industrial point-of-load conversion, emphasizing ultra-low IQ, dual-phase scalability, and rugged operation across -40°C to +125°C ambient.

FAQ

What is the maximum output current rating for MAX42406AFOA+?

The MAX42406AFOA+ is rated for 6A continuous output current under standard JEDEC board conditions at +70°C ambient. Its LX pin supports 6A RMS current, and the internal high-side MOSFET has a current-limit threshold of 7.5A (typ), enabling reliable operation in industrial loads with brief surge requirements. Derating applies above +70°C per the 38.41°C/W θ_JA thermal resistance.

Does MAX42406AFOA+ support dual-phase operation, and how is it configured?

Yes, MAX42406AFOA+ supports dual-phase operation using the VEA and SYNCOUT pins. One IC acts as controller (SYNC tied to BIAS), the other as target (SYNCOUT connected to target's SYNC). The controller's VEA pin drives the target's VEA pin to enforce matched current sharing. This configuration achieves ≤±3% current imbalance and scales total output to 12A while maintaining single-loop voltage regulation.

What is the purpose of the BIAS pin on MAX42406AFOA+, and what capacitor is required?

BIAS on MAX42406AFOA+ is the output of an internal 1.8V linear regulator that powers internal gate drivers and control circuitry. A minimum 2.2μF ceramic capacitor must be placed between BIAS and PGND to ensure stability and low-noise operation. During startup, BIAS draws from SUP; once VOUT exceeds 2.5V, it switches to output-derived supply - critical for efficiency in high-step-down applications.

How does the PGOOD function work on MAX42406AFOA+, and what is its threshold accuracy?

PGOOD on MAX42406AFOA+ is an open-drain output asserting low when VOUT falls outside 92–96% of its nominal value. Its threshold is trimmed to ±2% accuracy (94% ±2%) over temperature, with 100μs debounce for rising edges at 400kHz and 140μs at 1.5MHz. An external pull-up resistor is mandatory; typical use connects PGOOD to microcontroller reset or FPGA configuration logic for power sequencing validation.

Can MAX42406AFOA+ operate in dropout, and what is its maximum duty cycle?

Yes, MAX42406AFOA+ supports dropout operation with a maximum duty cycle of 96%, allowing regulation when input voltage approaches output voltage (e.g., 5.2V IN → 5.0V OUT). This is enabled by internal control-loop optimization and high-side driver design, making it suitable for brownout resilience in 24V industrial systems where input may sag to 23V under heavy load while maintaining 22.5V output.