Analog Devices Inc./Maxim Integrated MAX16938ATERA/V+T

Overview

MAX16938ATERA/V+T from Maxim Integrated is a 2.5A current-mode step-down DC-DC converter with integrated high-side and low-side MOSFETs, designed for automotive power supplies requiring 3.5V–36V input, 5V fixed output (±2% accuracy), 28µA no-load quiescent current, and resistor-programmable switching frequency from 220kHz to 2.2MHz. It supports forced-PWM (FPWM) and skip modes, features 180° out-of-phase SYNCOUT for cascaded supplies, and operates across –40°C to +125°C.

For engineers reviewing the MAX16938ATERA/V+T datasheet, MAX16938ATERA/V+T pinout, MAX16938ATERA/V+T application, or MAX16938ATERA/V+T equivalent, key selection considerations include its AEC-Q100 qualification, 42V load-dump tolerance, tight overvoltage protection (105% of V_FB), FPWM/EMI control via FSYNC, and compatibility with external Schottky diodes for efficiency optimization in automotive navigation and radio head units.

Technical Context

The MAX16938ATERA/V+T 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 balance EMI and efficiency. Its dual supply inputs (SUP and SUPSW) enable operation down to 3.5V while maintaining 98% maximum duty cycle during cold-crank transients.

It integrates a 5V BIAS linear regulator (4.7–5.4V output, ±200mV UVLO hysteresis) that powers internal circuitry until OUT reaches regulation, then transitions to OUT-supplied bias above 100mA load. The PGOOD output asserts at 95% V_FB, deasserts at 92% V_FB, with 10–50µs debounce, enabling precise power sequencing in multi-rail systems.

Key Specifications

Pinout & Package

MAX16938ATERA/V+T is housed in a 16-pin TSSOP-EP package with exposed thermal pad (EP), optimized for automotive thermal cycling and PCB heat dissipation. Pin mapping is identical to the MAX16936/MAX16938 family and validated per Maxim's official pinout documentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16936ATERA/V+T, the MAX16938ATERA/V+T offers tighter overvoltage protection critical for sensitive downstream ICs, while LM61480QRNXTQ1 trades integration for higher current capability but increases BOM count and layout complexity.

Availability

MAX16938ATERA/V+T is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera power supplies, and industrial control panels requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.

Supply support for MAX16938ATERA/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 precision analog, mixed-signal, and power-management ICs for automotive, industrial, and communications markets.

The MAX16936/MAX16938 product line targets automotive power conversion with emphasis on cold-crank resilience, load-dump survival, low quiescent current, and EMI-controlled operation in space-constrained ECUs.

FAQ

What is the fixed output voltage of the MAX16938ATERA/V+T and how is it configured?

The MAX16938ATERA/V+T provides a factory-trimmed fixed 5V output with ±2% accuracy over temperature and line. This is enabled by connecting the FB pin directly to the BIAS pin-no external resistors required. The 5V output is internally regulated against the 1.0V feedback reference (V_FB), ensuring stability across the full –40°C to +125°C automotive temperature range. For MAX16938ATERA/V+T, this configuration is the default and most commonly deployed setup in navigation head units and telematics modules.

Does the MAX16938ATERA/V+T support synchronization with an external clock source?

Yes, the MAX16938ATERA/V+T supports external clock synchronization via the FSYNC pin. When driven with a clean square wave between 1.8MHz and 2.6MHz (±20% of internal f_SW), the device locks within one cycle and disables internal spread-spectrum modulation. The external clock must have ≥100ns minimum pulse width. This capability allows MAX16938ATERA/V+T to align switching edges with other power stages or noise-sensitive RF sections-critical for meeting CISPR-25 emission limits in automotive radio systems.

How does the MAX16938ATERA/V+T handle undervoltage transients such as cold-crank events?

The MAX16938ATERA/V+T maintains regulation during cold-crank events (input down to 3.5V) by operating at up to 98% duty cycle. Its dual-supply architecture separates logic (SUP) and switch (SUPSW) rails, allowing the controller to sustain output even when input drops below nominal. Internal monitoring detects off-time ≤25ns for 12µs and forces low-side FET conduction to extend duty cycle. This behavior is confirmed in the "Slow VIN Ramp Behavior" test waveforms (Figures toc15–toc16) and enables reliable operation in engine-start scenarios without brownout resets.

What is the purpose of the SYNCOUT pin on the MAX16938ATERA/V+T and how is it used?

The SYNCOUT pin on the MAX16938ATERA/V+T provides an open-drain 180° out-of-phase clock signal relative to the internal oscillator. It is used to cascade multiple MAX16938ATERA/V+T devices in interleaved configurations-e.g., connecting SYNCOUT of Unit 1 to FSYNC of Unit 2 creates phase-shifted switching that cuts input/output ripple current by ~50%. Per datasheet Figure 1 and Pin Descriptions, SYNCOUT requires a pull-up resistor (100Ω–1kΩ) to OUT for 2MHz operation, enabling scalable power delivery without external timing ICs.

Is the MAX16938ATERA/V+T qualified for automotive applications and what standards does it meet?

Yes, the MAX16938ATERA/V+T is AEC-Q100 qualified for Grade 1 (–40°C to +125°C) operation and designed specifically for automotive use. It meets ISO 7637-2 Pulse 5a (load-dump up to 42V), supports cold-crank down to 3.5V, and incorporates thermal shutdown (175°C), cycle-by-cycle current limit, and overvoltage protection. These features are verified per Maxim's automotive qualification process and documented in the MAX16936/MAX16938 datasheet Rev 18, making MAX16938ATERA/V+T suitable for front-end power in infotainment, ADAS, and body-control modules.