Analog Devices Inc./Maxim Integrated MAX16939ATESA/V+T

Overview

MAX16939ATESA/V+T from Maxim Integrated is a 3.5A, 36V input automotive-grade 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 98% duty cycle during cold-crank transients-enabling reliable power delivery in automotive infotainment and ADAS ECUs.

For engineers reviewing the MAX16939ATESA/V+T datasheet, MAX16939ATESA/V+T pinout, MAX16939ATESA/V+T application, or MAX16939ATESA/V+T equivalent, key selection criteria include its AEC-Q100 qualification, tight ±2% output accuracy at 5V, 180° out-of-phase SYNCOUT for cascaded supplies, and integrated overvoltage protection with 105% threshold-critical for 12V/24V automotive rail regulation.

Technical Context

The MAX16939ATESA/V+T implements current-mode control with cycle-by-cycle current limiting and automatic LX slew-rate adjustment (4ns at >1.1MHz) to balance EMI and efficiency. Its dual supply inputs (SUP/SUPSW) support wide-input operation while maintaining internal bias regulation via the integrated 5V BIAS LDO.

It features three operating modes-skip mode (FSYNC = AGND), forced PWM (FSYNC = BIAS or external clock), and spread-spectrum modulation (factory-enabled)-with thermal shutdown at +175°C and automatic recovery. The 180° phase-shifted SYNCOUT enables precise interleaving of multiple converters without external delay networks.

Key Specifications

Pinout & Package

MAX16939ATESA/V+T is housed in a 16-pin 5mm × 5mm TQFN-EP package with exposed pad connected to PGND for thermal management. Pin functions are validated per Maxim's official datasheet revision 17 (1/18).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16935ATESA/V+T and LM61480QRNXTQ1, the MAX16939ATESA/V+T provides the tightest overvoltage protection (105% rising), built-in FPWM/skip mode selection via FSYNC, and guaranteed AEC-Q100 Grade-1 operation-making it optimal for safety-critical 5V automotive rails where output stability during transients is mandatory.

Availability

MAX16939ATESA/V+T is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, body control units, and telematics systems requiring stable component supply with full AEC-Q100 traceability and long-term lifecycle support.

Supply support for MAX16939ATESA/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 and mixed-signal ICs for automotive, industrial, and communications markets, with emphasis on power management, interface, and sensing solutions.

The MAX16935/MAX16939 product line delivers highly integrated, AEC-Q100-qualified DC-DC converters optimized for harsh automotive environments-specifically targeting 12V/24V battery-powered systems needing ultra-low IQ, wide VIN, and robust transient response.

FAQ

What is the maximum duty cycle supported by the MAX16939ATESA/V+T?

The MAX16939ATESA/V+T supports up to 98% duty cycle, enabling stable 5V output even during severe automotive cold-crank events where input voltage drops to 3.5V. This capability eliminates the need for pre-regulation stages in body control and infotainment applications, directly reducing BOM count and board space. The high-duty-cycle operation is sustained without thermal derating across the full -40°C to +125°C temperature range.

How does the MAX16939ATESA/V+T differ from the MAX16935ATESA/V+T in overvoltage protection?

The MAX16939ATESA/V+T features tighter overvoltage protection thresholds-105% (rising) and 102% (falling) at the FB pin-compared to 107%/105% for the MAX16935ATESA/V+T. This lower OVP trip point minimizes output overshoot during fast transients, making the MAX16939ATESA/V+T preferred for safety-critical 5V rails in ADAS and instrument cluster applications where strict voltage clamping is mandated.

Can the MAX16939ATESA/V+T operate in forced PWM mode without an external clock source?

Yes-the MAX16939ATESA/V+T enters forced PWM (FPWM) mode when the FSYNC pin is tied to the BIAS pin (5V), eliminating frequency variation under light loads. This configuration provides fixed-frequency operation across the entire load range without requiring an external clock generator, simplifying layout and reducing component count in RF-sensitive applications like cellular modems and radar power supplies.

What is the purpose of the SYNCOUT pin on the MAX16939ATESA/V+T?

The SYNCOUT pin on the MAX16939ATESA/V+T delivers an open-drain 180° out-of-phase clock signal relative to the internal oscillator, enabling precise interleaving of multiple MAX16939ATESA/V+T devices. When used to drive the FSYNC pin of a second converter, it creates a two-phase cascaded supply that cuts input/output ripple by ~30%, reduces EMI peak amplitude, and improves thermal distribution across parallel regulators.

Is an external Schottky diode required for the MAX16939ATESA/V+T despite its integrated low-side MOSFET?

Yes-an external Schottky diode is required between LX and AGND for full-load operation of the MAX16939ATESA/V+T. Although the device integrates a low-side MOSFET to enable FPWM mode, the diode remains necessary to handle peak currents beyond the MOSFET's conduction capability and to ensure efficiency across the full 0–3.5A load range, particularly at high switching frequencies and low input voltages.