Analog Devices Inc./Maxim Integrated MAX16935BAUES/V+T

Overview

MAX16935BAUES/V+T from Maxim Integrated is a 3.5A, current-mode synchronous step-down converter with integrated high-side and low-side MOSFETs, designed for automotive power supplies operating from 3.5V to 36V input. It delivers fixed 5V output with ±2% accuracy, supports resistor-programmable switching frequency from 220kHz to 2.2MHz, consumes only 28µA quiescent current at no load, and features FPWM/skip mode selection via FSYNC for EMI control-used in automotive navigation head units and RF transceiver power rails.

For engineers reviewing the MAX16935BAUES/V+T datasheet, MAX16935BAUES/V+T pinout, MAX16935BAUES/V+T application, or MAX16935BAUES/V+T equivalent, key selection criteria include its AEC-Q100 qualification, 98% max duty cycle for cold-crank support, 180° out-of-phase SYNCOUT for cascaded supplies, and thermal shutdown with automatic recovery-critical for under-hood automotive DC-DC design.

Technical Context

The MAX16935BAUES/V+T implements current-mode control with cycle-by-cycle current limiting and automatic LX slew-rate adjustment (4ns at >1.1MHz, 8ns otherwise) to balance EMI and efficiency. Its dual supply inputs (SUP/SUPSW) enable robust operation during load-dump (42V tolerant) and cold-crank transients.

It integrates a 5V BIAS LDO (4.7–5.4V output), supports external Schottky diode for enhanced light-load efficiency, and provides programmable overvoltage protection (107% threshold for MAX16935 variant) plus open-drain PGOOD with 95%/92% regulation window for precise power sequencing.

Key Specifications

Pinout & Package

MAX16935BAUES/V+T is housed in a 16-pin, 5mm × 5mm TQFN-EP package with exposed pad for thermal dissipation. The EP must be connected to PGND via a large-area copper plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16939BAUES/V+T, the MAX16935BAUES/V+T provides higher OVP threshold margin and lower skip-mode activation current, making it more tolerant of transient overshoot and better for light-load efficiency in non-safety-critical rails; versus LM61480QRNXTQ1, it delivers superior integration (BIAS LDO, SYNCOUT, PGOOD) and reduced BOM count despite identical current rating and input range.

Availability

MAX16935BAUES/V+T is available at Aetrix Electronics and suitable for automotive navigation systems, RF transceiver power supplies, and distributed DC power architectures requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.

Supply support for MAX16935BAUES/V+T 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, mixed-signal, and power-management ICs for automotive, industrial, and communications markets.

The MAX16935/MAX16939 product line targets automotive power conversion with emphasis on cold-crank resilience, low quiescent current, and EMI-aware operation-specifically engineered for infotainment, ADAS, and telematics subsystems.

FAQ

What is the maximum duty cycle supported by the MAX16935BAUES/V+T, and why is it important?

The MAX16935BAUES/V+T supports up to 98% maximum duty cycle. This is critical for automotive applications where input voltage can drop to 3.5V during cold-crank events-the high duty cycle allows the device to maintain regulated 5V output even with minimal VIN–VOUT differential, preventing system brownout. This capability is explicitly validated per AEC-Q100 stress testing protocols.

Does the MAX16935BAUES/V+T require an external Schottky diode, and if so, why?

Yes, the MAX16935BAUES/V+T requires an external Schottky diode connected between LX and AGND. Although it integrates high- and low-side MOSFETs, the diode improves light-load efficiency by providing a low-loss freewheeling path-especially beneficial in skip mode. The datasheet specifies this requirement for optimal performance across the full 0–3.5A load range.

How does the FSYNC pin affect operating mode selection in the MAX16935BAUES/V+T?

The FSYNC pin selects between skip mode and forced-PWM (FPWM) mode: connecting FSYNC to AGND enables skip mode for lowest quiescent current, while connecting to BIAS or an external clock forces FPWM for constant frequency and minimized EMI. The MAX16935BAUES/V+T synchronizes to external clocks within ±20% frequency deviation and reverts to internal oscillator if clock is absent for >2 cycles.

What is the function of the SYNCOUT pin on the MAX16935BAUES/V+T, and how is it used in system design?

The SYNCOUT pin on the MAX16935BAUES/V+T is an open-drain output that delivers a 180° out-of-phase clock signal relative to the internal oscillator. It is used to synchronize multiple MAX16935BAUES/V+T devices in interleaved configurations-reducing input/output ripple current, easing EMI filtering, and increasing total system power capacity without increasing per-rail current stress.

Is the MAX16935BAUES/V+T qualified for automotive applications, and what standards does it meet?

Yes, the MAX16935BAUES/V+T is AEC-Q100 qualified for automotive use across the –40°C to +125°C junction temperature range. It meets stringent automotive reliability requirements including thermal shutdown with automatic recovery, 42V load-dump tolerance, and robust ESD protection. Its TQFN-EP package and internal protections (cycle-by-cycle current limit, OVP, PGOOD) are all validated per AEC-Q100 test conditions.