Analog Devices Inc./Maxim Integrated MAX16939ATERA/V+

Overview

MAX16939ATERA/V+ from Maxim Integrated is a 3.5A, 36V input current-mode synchronous step-down converter with integrated high-side and low-side MOSFETs, 28µA quiescent current, resistor-programmable 220kHz–2.2MHz switching frequency, and fixed 5V output (±2% accuracy). It operates across -40°C to +125°C and supports automotive cold-crank and load-dump conditions up to 42V, making it suitable for navigation head units and RF transceiver power supplies.

For engineers reviewing the MAX16939ATERA/V+ datasheet, MAX16939ATERA/V+ pinout, MAX16939ATERA/V+ application, or MAX16939ATERA/V+ equivalent, key selection considerations include its FPWM/skip mode control via FSYNC, 180° out-of-phase SYNCOUT for cascaded supplies, tight overvoltage protection (105% threshold), AEC-Q100 qualification, and TQFN-EP 5mm × 5mm package with exposed thermal pad.

Technical Context

The MAX16939ATERA/V+ implements current-mode control with cycle-by-cycle current limiting and automatic LX slew-rate adjustment-4ns rise time at >1.1MHz, 8ns below-to optimize EMI/efficiency trade-offs. Its dual supply inputs (SUP and SUPSW) enable operation down to 3.5V while sustaining 98% duty cycle during undervoltage transients.

It integrates a 5V BIAS linear regulator (4.7–5.4V output, ±2.95–3.40V UVLO), open-drain PGOOD with 95%/92% VFB thresholds, and overvoltage protection that forces low-side conduction upon threshold breach. The device supports external clock synchronization (1.8–2.6MHz) and factory-enabled spread-spectrum modulation (±6%) when not synced.

Key Specifications

Pinout & Package

MAX16939ATERA/V+ is housed in a 16-pin 5mm × 5mm TQFN-EP package with exposed thermal pad (EP) connected to PGND for enhanced thermal dissipation. The package supports JEDEC-standard reflow and achieves 35°C/W junction-to-ambient thermal resistance on multilayer PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with MAX16935ATERA/V+, the MAX16939ATERA/V+ provides tighter overvoltage protection for safety-critical 5V rails, while the LM61480QRNLRQ1 offers lower quiescent current but requires external components and lacks phase-sync capability-making MAX16939ATERA/V+ optimal for compact, EMI-sensitive automotive POL designs.

Availability

MAX16939ATERA/V+ is available at Aetrix Electronics and suitable for automotive infotainment, RF transceiver power, and industrial camera module applications requiring stable component supply, AEC-Q100 compliance, and high-temperature operation.

Supply support for MAX16939ATERA/V+ 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, designs high-performance analog and mixed-signal ICs for automotive, industrial, and communications markets with emphasis on power efficiency and reliability.

The MAX16935/MAX16939 product line targets automotive power conversion, delivering robust 36V-input buck regulators with integrated FETs, low IQ, and AEC-Q100 qualification for demanding under-hood and infotainment applications.

FAQ

What is the output voltage tolerance of the MAX16939ATERA/V+?

The MAX16939ATERA/V+ delivers a fixed 5V output with ±2% accuracy over temperature, line, and load conditions. This corresponds to a guaranteed range of 4.90V to 5.10V at the FB pin under FPWM mode, verified across -40°C to +125°C and input voltages from 6V to 36V.

How does the MAX16939ATERA/V+ handle undervoltage transients such as cold crank?

The MAX16939ATERA/V+ sustains operation down to 3.5V input and supports up to 98% duty cycle during undervoltage events. When input drops below the regulated 5V output, the device enters high-duty-cycle mode to minimize dropout-enabling uninterrupted power to navigation processors during engine cranking.

Can the MAX16939ATERA/V+ be synchronized to an external clock, and what is the acceptable frequency range?

Yes, the MAX16939ATERA/V+ accepts external synchronization via the FSYNC pin across 1.8MHz to 2.6MHz-±20% of its internal 2.2MHz oscillator frequency. The device locks to the external clock within one cycle and reverts to internal oscillation if the signal is absent for more than two cycles.

What is the purpose of the SYNCOUT pin on the MAX16939ATERA/V+?

The SYNCOUT pin on the MAX16939ATERA/V+ provides an open-drain 180° out-of-phase clock signal relative to the internal oscillator. It enables phase-interleaved operation with a second MAX16939ATERA/V+ to reduce input/output ripple current and lower EMI peaks in multi-rail power systems.

Does the MAX16939ATERA/V+ require an external Schottky diode, and why?

Yes, the MAX16939ATERA/V+ requires an external Schottky diode connected between LX and AGND. Although it integrates low-side MOSFETs for FPWM operation, the diode supports full 3.5A load capability and ensures reliable conduction during skip mode and transient overload conditions where the internal FET may not fully replace diode functionality.