Analog Devices Inc./Maxim Integrated MAX16935RATE/V+

Overview

MAX16935RATE/V+ from Maxim Integrated is a 36V, 3.5A current-mode synchronous step-down converter with integrated high-side and low-side MOSFETs, 28µA quiescent current, resistor-programmable switching frequency (220kHz–2.2MHz), and fixed 5V output. It operates across -40°C to +125°C and supports automotive cold-crank and load-dump conditions (42V tolerant) in navigation head units and RF transceiver power supplies.

For engineers reviewing the MAX16935RATE/V+ datasheet, MAX16935RATE/V+ pinout, MAX16935RATE/V+ application, or MAX16935RATE/V+ equivalent, key selection criteria include its FPWM/skip mode control via FSYNC, 180° out-of-phase SYNCOUT for cascaded supplies, ±2% output accuracy, AEC-Q100 qualification, and thermal shutdown with automatic recovery.

Technical Context

The MAX16935RATE/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 input while sustaining 98% duty cycle during undervoltage transients.

It integrates a 5V BIAS linear regulator (4.7–5.4V, ±650mV hysteresis), open-drain PGOOD with 95%/92% VFB thresholds, and overvoltage protection (107% for MAX16935). The FSYNC pin selects skip mode (FSYNC = AGND) or forced-PWM (FSYNC = BIAS/external clock), enabling EMI-sensitive RF supply designs.

Key Specifications

Pinout & Package

MAX16935RATE/V+ is housed in a 16-pin 5mm × 5mm TQFN-EP package with exposed pad connected to PGND for thermal dissipation. Pin functions are validated per Maxim's official datasheet (Rev 17, Jan 2018).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQR and TPS62933RQYR, the MAX16935RATE/V+ uniquely combines AEC-Q100 qualification, 180° SYNCOUT for interleaving, FSYNC-selectable FPWM/skip modes, and spread-spectrum EMI reduction-making it the only option qualified for safety-critical automotive power domains requiring both performance and compliance.

Availability

MAX16935RATE/V+ is available at Aetrix Electronics and suitable for automotive infotainment, RF transceiver bias, and industrial control module applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for MAX16935RATE/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 management, precision sensing, and secure connectivity.

The MAX16935RATE/V+ belongs to Maxim's automotive-grade DC-DC converter product line, engineered specifically for demanding vehicular environments requiring wide-input operation, ultra-low quiescent current, and robust fault protection.

FAQ

What is the maximum input voltage rating for MAX16935RATE/V+, and how does it handle load-dump transients?

The MAX16935RATE/V+ supports 3.5V to 36V nominal input and is rated for 42V transient tolerance per Absolute Maximum Ratings. During load-dump events (≤1s, 42V), the device remains functional without latch-up or damage due to internal protection circuitry and robust gate oxide design. Its 98% maximum duty cycle ensures continued regulation even as input collapses during cold-crank scenarios-critical for automotive head unit reliability. This behavior is verified across the full -40°C to +125°C operating range.

Does MAX16935RATE/V+ support adjustable output voltages, or is it fixed at 5V?

The MAX16935RATE/V+ is configured for fixed 5V output (±2% accuracy) as indicated by its /V+ suffix and confirmed in the Ordering Information section of the datasheet. While the MAX16935 family includes adjustable variants (e.g., MAX16935AAT/V+), the MAX16935RATE/V+ variant uses internal feedback routing to BIAS, locking VOUT at 5V. External resistor dividers on FB are not supported for this specific part number-attempting adjustment will result in incorrect regulation.

How does the FSYNC pin control operating mode in MAX16935RATE/V+?

The FSYNC pin on MAX16935RATE/V+ selects between skip mode and forced-PWM (FPWM) operation: connecting FSYNC to AGND enables skip mode for light-load efficiency, while pulling FSYNC to BIAS or an external clock forces FPWM mode across all loads. In FPWM mode, the device maintains constant switching frequency (set by RFOSC or external clock), eliminating variable-frequency EMI-a key requirement for RF transceiver power supplies. Mode transition occurs within one switching cycle.

What thermal management features does MAX16935RATE/V+ include, and how is junction temperature monitored?

MAX16935RATE/V+ incorporates thermal shutdown at +175°C (typical) with 15°C hysteresis, enabling automatic recovery once junction temperature falls below +160°C. Thermal protection is implemented via an on-die sensor that disables the internal bias regulator and step-down controller during overtemperature events. The TQFN-EP package provides 2.7°C/W junction-to-case thermal resistance, and the exposed pad must be soldered to a large PGND copper area to achieve specified 35°C/W junction-to-ambient performance per JEDEC 51.

Is MAX16935RATE/V+ pin-compatible with other devices in the MAX16935/MAX16939 family?

Yes, MAX16935RATE/V+ shares identical pinout, package (16-pin TQFN-EP), and footprint with all MAX16935 and MAX16939 variants-including MAX16935AAT/V+, MAX16935CATE/V+, and MAX16939. This allows drop-in replacement for different output voltages (3.3V/5V), accuracy grades, or protection features (e.g., tighter OVP in MAX16939) without PCB redesign. However, functional differences (e.g., FSYNC behavior, OVP threshold) must be verified in system-level validation.