Analog Devices Inc./Maxim Integrated MAX1649EVKIT-SO+

Overview

MAX1649EVKIT-SO+ from Maxim Integrated is an evaluation kit for the MAX1649 fixed 5V, high-efficiency, low-dropout step-down DC-DC controller IC. It supports input voltages from 3.6V to 16V, delivers up to 1.5A output current with >90% efficiency across 10mA–1.5A loads, and features 100µA quiescent supply current and <300mV dropout at 500mA - enabling use in battery-powered PDAs and green PC 5V-to-3.3V regulation.

For engineers reviewing the MAX1649EVKIT-SO+ datasheet, MAX1649EVKIT-SO+ pinout, MAX1649EVKIT-SO+ application, or MAX1649EVKIT-SO+ equivalent, this kit provides validated reference design, thermal performance data, transient response waveforms, and component selection guidance for integrating the MAX1649 controller into high-efficiency, low-quiescent-power buck regulator systems.

Technical Context

The MAX1649EVKIT-SO+ implements a BiCMOS current-limited pulse-frequency-modulated (PFM) control scheme that combines low-noise light-load operation (100µA I_Q) with high-efficiency heavy-load performance (>90% at 1A) via peak-current limiting and programmable on/off timing. It drives an external P-channel MOSFET (Si9430) and uses a 47µH inductor, 330µF output capacitor, and 0.05Ω current-sense resistor to achieve continuous-conduction mode operation up to 1.5A.

This kit validates the MAX1649's fixed 5V output configuration using OUT-to-FB grounding, REF bypassed with 0.1µF, and SHDN tied to GND for active operation. It demonstrates line/ load transient response (e.g., 6V–16V input step, 30mA–1.6A load step), shutdown recovery (<1ms), and dropout behavior down to 300mV under 1.5A load - all measured per Figure 1 of the MAX1649 datasheet.

Key Specifications

Availability

MAX1649EVKIT-SO+ is available at Aetrix Electronics and suitable for PDA power management, green PC voltage translation, and battery-powered embedded regulation requiring stable component supply, rapid prototyping validation, and production-ready reference design fidelity.

Supply support for MAX1649EVKIT-SO+ 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

Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, computing, and portable applications.

The MAX1649EVKIT-SO+ belongs to Maxim's legacy high-efficiency DC-DC controller evaluation platform family, designed specifically to accelerate development of low-quiescent, low-dropout buck regulators for space- and power-constrained systems.

FAQ

What is the primary function of the MAX1649EVKIT-SO+?

The MAX1649EVKIT-SO+ is a fully assembled and tested evaluation kit for the MAX1649 fixed-5V step-down DC-DC controller. It provides a working reference design - including Si9430 P-MOSFET, 47µH inductor, 330µF output capacitor, and 0.05Ω sense resistor - to validate performance metrics such as efficiency, dropout, transient response, and thermal behavior before custom PCB design. The MAX1649EVKIT-SO+ directly implements the circuit shown in Figure 1 of the MAX1649 datasheet.

Does the MAX1649EVKIT-SO+ support adjustable output voltages?

No - the MAX1649EVKIT-SO+ is configured exclusively for the MAX1649's fixed 5V output mode, with FB grounded and OUT unconnected per the MAX1649 pinout. It does not implement the resistor-divider feedback network required for adjustable operation (1.5V–V_IN). For 3.3V or adjustable output evaluation, users must select the MAX1651-based kit or modify the board per the MAX1649/MAX1651 datasheet's Figure 4 schematic.

Which external components are included on the MAX1649EVKIT-SO+ board?

The MAX1649EVKIT-SO+ includes: Si9430 P-channel MOSFET (SOT-223), Sumida CDRH125-470 47µH shielded inductor, Sprague 595D337X9010R2T 330µF/10V low-ESR output capacitor, 1N5820 Schottky diode, 0.05Ω surface-mount current-sense resistor, and 0.1µF ceramic capacitors on V+, REF, and EXT. All values match those specified in the MAX1649 Typical Operating Circuit (Figure 1).

Can the MAX1649EVKIT-SO+ be used to evaluate the MAX1651?

No - the MAX1649EVKIT-SO+ is hardware-optimized for the MAX1649 (5V fixed output) and is not compatible with the MAX1651 (3.3V fixed output) without modification. While both ICs share identical pinouts and control architecture, the MAX1651 requires different feedback configuration (FB grounded, but output set to 3.3V), distinct current-sense resistor sizing (per Figure 5b), and validation of 3.3V-specific transient/load behavior. Maxim offers separate kits for MAX1651 evaluation.

What thermal and transient performance data is provided with the MAX1649EVKIT-SO+?

The MAX1649EVKIT-SO+ documentation includes measured line-transient response (6V→16V input step), load-transient response (30mA→1.6A step), shutdown recovery time (<1ms), and continuous-conduction mode waveform (Figure 3). Thermal performance is validated via ambient temperature sweeps showing stable operation from –40°C to +85°C, with supply current drift characterized per Figures TOC05–TOC06 - all directly tied to MAX1649 electrical specifications in the datasheet.