Analog Devices Inc./Maxim Integrated MAX16935SAUE/V+CNL

Overview

MAX16935SAUE/V+CNL from Maxim Integrated is a 3.5A, current-mode synchronous step-down DC-DC 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 up to 2.2MHz, and features 28µA quiescent current at no load-enabling always-on functionality in vehicle infotainment systems.

For engineers reviewing the MAX16935SAUE/V+CNL datasheet, MAX16935SAUE/V+CNL pinout, MAX16935SAUE/V+CNL application, or MAX16935SAUE/V+CNL equivalent, key selection criteria include its AEC-Q100 qualification, 98% max duty cycle for cold-crank resilience, FPWM/skip mode control via FSYNC, 180° out-of-phase SYNCOUT for cascaded rails, and integrated thermal shutdown with automatic recovery.

Technical Context

The MAX16935SAUE/V+CNL implements a current-mode control architecture with internal slope compensation, enabling stable operation across wide VIN and VOUT ranges. Its dual-supply inputs (SUP and SUPSW) decouple logic and power-switch domains, supporting undervoltage transients down to 3.5V while maintaining regulation via 98% duty cycle capability.

It integrates a 5V BIAS linear regulator, programmable oscillator (220kHz–2.2MHz), and open-drain PGOOD/SYNCOUT outputs. The device uses automatic LX slew-rate adjustment-4ns rise time above 1.1MHz-to balance EMI reduction and efficiency, and includes cycle-by-cycle current limiting, overvoltage protection (107% threshold), and thermal shutdown at +175°C with 15°C hysteresis.

Key Specifications

Pinout & Package

MAX16935SAUE/V+CNL is housed in a 16-pin, 5mm × 5mm TQFN-EP package with exposed pad connected to PGND for thermal management. Pin count, layout, and thermal characteristics match the MAX16935 family's automotive-grade footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480QRNXTQ1 and TPS62933RQWR, the MAX16935SAUE/V+CNL uniquely combines AEC-Q100 qualification, 98% duty cycle, integrated low-side FET for FPWM, and 180° SYNCOUT-making it the only option among the three qualified for demanding automotive power rails requiring EMI control, cold-crank resilience, and cascaded supply scalability.

Availability

MAX16935SAUE/V+CNL is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and telematics gateways requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant performance.

Supply support for MAX16935SAUE/V+CNL 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, emphasizing reliability, integration, and power efficiency.

The MAX16935 product line targets automotive power management with AEC-Q100 qualification, cold-crank resilience, and EMI-optimized features-specifically engineered for infotainment, ADAS, and body electronics requiring robust 5V/3.3V rails.

FAQ

What is the maximum duty cycle supported by the MAX16935SAUE/V+CNL, and why is it important for automotive use?

The MAX16935SAUE/V+CNL supports up to 98% duty cycle, enabling continued regulation during severe undervoltage transients such as engine cranking-where battery voltage can dip to 3.5V. This ensures uninterrupted 5V output to critical systems like infotainment processors and CAN controllers, preventing brownouts and system resets in real-world automotive environments.

Does the MAX16935SAUE/V+CNL require an external Schottky diode, and if so, why?

Yes, the MAX16935SAUE/V+CNL requires an external Schottky diode connected from LX to AGND-even though it integrates both high-side and low-side MOSFETs. The diode improves light-load efficiency and supports operation across the full 3.5A load range, especially in skip mode where the internal low-side FET alone cannot sustain conduction during deep discontinuous conduction mode.

How does the FSYNC pin control operating mode, and what are the practical implications of each setting?

The FSYNC pin selects between skip mode (FSYNC = AGND) for highest light-load efficiency, and forced-PWM mode (FSYNC = BIAS or external clock) for fixed-frequency operation that minimizes EMI variability. In RF-sensitive applications like car radios or cellular modems, forced-PWM eliminates frequency jitter-simplifying EMI filter design and ensuring compliance with CISPR 25 Class 5 limits.

What is the purpose of the SYNCOUT pin, and how is it used in multi-rail power systems?

The SYNCOUT pin provides an open-drain 180° out-of-phase clock signal relative to the internal oscillator. When two MAX16935SAUE/V+CNL devices are synchronized-one driving SYNCOUT into the FSYNC of the second-their switching phases interleave. This cuts input/output ripple current by ~70%, allowing smaller input capacitors and reduced thermal stress in high-current automotive power trees.

Is the MAX16935SAUE/V+CNL AEC-Q100 qualified, and which grade does it meet?

Yes, the MAX16935SAUE/V+CNL is AEC-Q100 qualified per Grade 1 standards, covering operation from −40°C to +125°C ambient temperature. This qualification includes stress testing for temperature cycling, humidity, mechanical shock, and ESD-ensuring reliability in automotive under-hood and cabin environments where thermal and vibration demands are most stringent.