Analog Devices Inc./Maxim Integrated MAX5035CASA+

Overview

The MAX5035CASA+ from Maxim Integrated is a high-voltage, 1A step-down DC-DC converter with fixed 12V output, operating from 15V to 76V input and delivering up to 94% efficiency at 24V_IN/0.5A. It integrates a 0.4Ω high-side DMOS FET, internal frequency compensation, and automotive-grade -40°C to +125°C operation in an 8-pin SO package. Used in industrial power supplies and automotive subsystems requiring robust wide-input regulation.

For engineers reviewing the MAX5035CASA+ datasheet, MAX5035CASA+ pinout, MAX5035CASA+ application, or MAX5035CASA+ equivalent, key selection criteria include its 12V fixed output, 125kHz switching frequency, 270µA no-load quiescent current, thermal shutdown at +160°C, and compatibility with external Schottky rectifiers like 50SQ100 for high-efficiency buck conversion.

Technical Context

This voltage-mode buck regulator uses feed-forward control and an internal high-side DMOS switch to maintain stable regulation across a wide 15V–76V input range. Its fixed 125kHz PWM operation transitions automatically to pulse-skipping mode under light loads to sustain high efficiency and low 270µA quiescent draw.

Protection features include cycle-by-cycle current limiting (1.3–2.5A peak), hiccup-mode short-circuit response, undervoltage lockout (5.2V typ), and thermal shutdown with 20°C hysteresis. The device requires only external components: bootstrap capacitor (0.1µF), output sense (FB tied to V_OUT), Schottky diode, and LC filter.

Key Specifications

Pinout & Package

MAX5035CASA+ is housed in an 8-pin SO (Small Outline) package, JEDEC MS-012AC compliant, with exposed pad not electrically connected. Thermal resistance θ_JA = 170°C/W (JEDEC 51).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5017MM/NOPB and TPS54360DGQR, the MAX5035CASA+ uniquely combines 76V input support, automotive temperature range, integrated 12V regulator (VD), and fixed 12V output in a compact SO-8 - making it optimal for space-constrained, high-reliability 12V systems where input voltage can exceed 60V.

Availability

MAX5035CASA+ is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, distributed telecom equipment, and railway signaling systems requiring stable component supply across extended temperature and high-input-voltage conditions.

Supply support for MAX5035CASA+ 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 demanding industrial, automotive, and communications applications.

The MAX5035 product line delivers high-voltage, high-efficiency step-down DC-DC conversion for systems powered from unregulated 12V–76V sources - targeting automotive subsystems, industrial controls, and telecom infrastructure where reliability and wide input range are critical.

FAQ

What is the maximum input voltage rating for the MAX5035CASA+?

The MAX5035CASA+ has an absolute maximum input voltage rating of +80V, with continuous operation specified from 15V to 76V. This 76V operating limit ensures reliable performance in 24V and 48V industrial systems, as well as 12V automotive applications subject to load-dump transients. Exceeding 76V during normal operation may trigger undervoltage lockout or damage the internal DMOS switch.

Does the MAX5035CASA+ require external compensation components?

No, the MAX5035CASA+ includes internal frequency compensation optimized for stability with standard LC output filters. This eliminates the need for external compensation networks such as type-II or type-III error amplifier circuits. Designers can implement the MAX5035CASA+ using only the required external components: input/output capacitors, inductor, Schottky diode, and bootstrap capacitor - significantly reducing bill-of-materials count and layout complexity.

How does the MAX5035CASA+ handle short-circuit conditions on the output?

The MAX5035CASA+ employs hiccup-mode short-circuit protection: when output current exceeds the cycle-by-cycle limit (1.3–2.5A), the device shuts down the switch, waits a recovery period, then attempts restart. This prevents thermal runaway and limits average power dissipation during sustained faults. Unlike constant-current limiting, hiccup mode reduces junction temperature rise and avoids latch-up, enabling safe automatic recovery once the fault is removed.

What is the purpose of the VD pin on the MAX5035CASA+?

VD is the output of an internal linear regulator that supplies ~7.8V (6.5–9.0V range) to power internal analog and gate-drive circuitry. It must be bypassed to GND with a 0.1µF ceramic capacitor. This dedicated bias rail isolates sensitive control circuitry from noisy power paths, improves noise immunity, and enables reliable high-side gate drive without requiring an external LDO - a key enabler of the MAX5035CASA+'s single-chip 12V/1A buck functionality.

Can the MAX5035CASA+ be used with an adjustable output voltage?

No, the MAX5035CASA+ is a fixed-output variant configured for 12V. It belongs to the MAX5035C family, which has factory-trimmed feedback circuitry connecting FB internally to the 12V reference. For adjustable output (1.25V–13.2V), select MAX5035DASA+ or MAX5035EASA+, which expose the FB pin for external resistor-divider configuration. Attempting to modify the MAX5035CASA+ for adjustable output will result in incorrect regulation or instability due to mismatched internal reference topology.