Analog Devices Inc./Maxim Integrated MAX16938ATESA/V+T

Overview

MAX16938ATESA/V+T from Maxim Integrated is a 2.5A current-mode synchronous step-down DC-DC converter with integrated high-side and low-side MOSFETs, designed for automotive power supplies requiring 3.5V–36V input, 5V/3.3V fixed or 1V–10V adjustable output, 220kHz–2.2MHz resistor-programmable switching frequency, and 28µA no-load quiescent current. It supports forced-PWM (FPWM) and skip modes, features 98% max duty cycle for cold-crank resilience, and includes AEC-Q100 qualification.

For engineers reviewing the MAX16938ATESA/V+T datasheet, MAX16938ATESA/V+T pinout, MAX16938ATESA/V+T application, or MAX16938ATESA/V+T equivalent, key selection considerations include its 180° out-of-phase SYNCOUT for cascaded supplies, tight ±2% fixed-output accuracy, 42V load-dump protection, thermal shutdown with automatic recovery, and FPWM mode for EMI-sensitive RF transceiver power rails.

Technical Context

The MAX16938ATESA/V+T implements current-mode control with cycle-by-cycle current limiting and automatic LX slew-rate adjustment-4ns rise time above 1.1MHz, 8ns below-to optimize EMI-efficiency trade-offs. Its dual supply inputs (SUP/SUPSW) enable robust operation during undervoltage transients, while the internal 5V BIAS LDO powers control circuitry until output regulation is achieved.

It integrates a transconductance error amplifier (gm = 700µS), 1V FB reference with ±1.5% tolerance over temperature, and programmable soft-start (5.6–12ms). The device supports external clock synchronization (1.8–2.6MHz), spread-spectrum modulation (±6%), and offers distinct overvoltage protection thresholds: 105% for MAX16938 vs. 107% for MAX16936-enabling tighter output clamping in safety-critical automotive domains.

Key Specifications

Pinout & Package

MAX16938ATESA/V+T is housed in a 16-pin TSSOP-EP package with exposed pad for thermal dissipation. Pin numbering follows standard TSSOP top-view convention; EP must be soldered to a large-area PGND copper plane but not used as sole ground connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16936ATESA/V+T and LM61480QRNXTQ1, the MAX16938ATESA/V+T uniquely combines 105% OVP clamping, 180° SYNCOUT for interleaving, and spread-spectrum EMI reduction - making it optimal for compact, multi-rail automotive power systems demanding both safety and emission compliance.

Availability

MAX16938ATESA/V+T is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and industrial telematics gateways requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for MAX16938ATESA/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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for automotive, industrial, and communications markets.

The MAX16936/MAX16938 product line was engineered specifically for automotive DC-DC conversion - emphasizing wide VIN range, ultra-low IQ, AEC-Q100 qualification, and integrated protection features to simplify power design in harsh vehicle environments.

FAQ

What is the key functional difference between MAX16938ATESA/V+T and MAX16936ATESA/V+T?

The MAX16938ATESA/V+T features a tighter 105% overvoltage protection (OVP) threshold versus the MAX16936ATESA/V+T's 107% OVP. This lower trip point reduces output overshoot during feedback-loop faults, enhancing safety for downstream 5V-tolerant components. Both share identical pinout, package, and all other electrical specifications - making MAX16938ATESA/V+T the preferred choice where stricter OVP is mandated by system-level safety requirements.

How does the FSYNC pin configure operating mode in MAX16938ATESA/V+T?

In MAX16938ATESA/V+T, the FSYNC pin selects between skip mode and forced-PWM (FPWM) mode: connecting FSYNC to AGND enables skip mode for highest light-load efficiency, while tying it to BIAS or an external clock forces FPWM operation across all load conditions. FPWM eliminates frequency variation, which is essential for minimizing conducted EMI in RF-sensitive applications like automotive radio head units - a capability directly enabled by the low-side MOSFET integration in MAX16938ATESA/V+T.

What thermal performance can be expected from MAX16938ATESA/V+T in a typical automotive layout?

When mounted on a 4-layer PCB with the exposed pad (EP) soldered to a ≥200mm² contiguous PGND copper plane, MAX16938ATESA/V+T achieves a junction-to-ambient thermal resistance (θ_JA) of 38.3°C/W in TSSOP-EP. At 2.5A load and 14V input, typical power dissipation is ~1.2W - resulting in ~46°C junction rise above ambient. Thermal shutdown activates at +175°C with 15°C hysteresis, ensuring reliable self-protection even under sustained high-temperature operation in under-hood environments.

Can MAX16938ATESA/V+T operate with a 3.5V input during cold-crank conditions?

Yes - MAX16938ATESA/V+T supports input voltages as low as 3.5V and maintains regulation via 98% maximum duty cycle operation. During cold-crank, when battery voltage dips to ~3.5V, the IC sustains output by extending on-time to near-maximum, enabling uninterrupted power to critical loads like microcontrollers and CAN transceivers. This behavior is validated across the full -40°C to +125°C automotive temperature range and is a core design feature distinguishing MAX16938ATESA/V+T from non-automotive buck regulators.

What is the purpose of the SYNCOUT pin in MAX16938ATESA/V+T, and how is it used?

The SYNCOUT pin in MAX16938ATESA/V+T delivers an open-drain 180° out-of-phase clock signal relative to the internal oscillator. It is used to synchronize a second MAX16938ATESA/V+T (or compatible converter) in a cascaded configuration - halving input ripple current and spreading EMI energy across two frequencies. To implement, connect SYNCOUT to the FSYNC pin of the second device through a pull-up resistor (1kΩ–10kΩ to BIAS), enabling phase-interleaved operation without external timing components.