Analog Devices Inc./Maxim Integrated MAX17245ETESB+

Overview

MAX17245ETESB+ from Maxim Integrated is a 3.5A synchronous step-down DC-DC converter with integrated high-side and low-side MOSFETs, operating from 3.5V to 36V input and delivering fixed 3.3V/5V or adjustable 1V–10V output. It features 28µA quiescent current, 98% max duty cycle for dropout operation, and 220kHz–2.2MHz resistor-programmable switching frequency-used in automotive infotainment power rails and industrial point-of-load regulation.

For engineers reviewing the MAX17245ETESB+ datasheet, MAX17245ETESB+ pinout, MAX17245ETESB+ application, or MAX17245ETESB+ equivalent, key selection criteria include input transient tolerance (42V), PFM/PWM mode control via FSYNC, ±2% fixed-output accuracy, spread-spectrum EMI reduction, and thermal shutdown with automatic recovery at +175°C.

Technical Context

The MAX17245ETESB+ employs current-mode control with selectable PWM or PFM operation: PWM maintains constant 220kHz–2.2MHz frequency across load, while PFM disables negative inductor current and skips pulses at light loads to achieve >90% peak efficiency. Its internal 5V BIAS LDO powers control circuitry and enables startup from 3.5V input.

It integrates dual MOSFETs (RON_H = 100–220mΩ, RON_L = 1.5–3Ω), supports external synchronization via FSYNC (1.8–2.6MHz), and delivers 180° out-of-phase SYNCOUT for cascaded supplies. Protection includes cycle-by-cycle current limit, overvoltage protection (102–105% VFB), and thermal shutdown with 15°C hysteresis.

Key Specifications

Pinout & Package

MAX17245ETESB+ is housed in a 16-pin 5mm × 5mm TQFN package with exposed pad (EP), optimized for thermal dissipation (θJA = 35°C/W on multilayer board). The EP must be soldered to a large-area PGND copper plane but cannot serve as sole ground connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with LM61480RQWR and TPS54560BQDDARQ1, the MAX17245ETESB+ uniquely integrates a 5V BIAS LDO, 180° SYNCOUT, and factory-set spread-spectrum - making it optimal for compact, EMI-sensitive, multi-rail automotive and industrial designs where auxiliary supplies and layout space are constrained.

Availability

MAX17245ETESB+ is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLCs, and RF transceiver power supplies requiring stable component supply, long-lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for MAX17245ETESB+ 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 MAX17245 belongs to Maxim's high-efficiency synchronous buck converter product line, engineered for wide-input automotive and industrial power rails where input transients, low quiescent current, and EMI robustness are critical.

FAQ

What input voltage range does the MAX17245ETESB+ support, and how does it handle transients?

The MAX17245ETESB+ operates from 3.5V to 36V DC input and withstands 42V transients for up to 1 second. Its dual-supply architecture (SUP and SUPSW) enables reliable cold-crank operation down to 3.5V, while the 98% maximum duty cycle maintains regulation during undervoltage events. This makes MAX17245ETESB+ suitable for automotive battery systems subject to load-dump and cranking conditions without external protection circuitry.

How is the output voltage configured on the MAX17245ETESB+?

The MAX17245ETESB+ supports both fixed and adjustable outputs: connect FB directly to BIAS for 5V (±2%), or use an external resistor divider from OUT to FB to AGND for 1V–10V programmability. The internal 1.0V feedback reference ensures ±0.5% load regulation and 0.02%/V line regulation. For 3.3V fixed output, a different variant (MAX17245ETE33+) is required - the MAX17245ETESB+ is specifically configured for 5V fixed or adjustable operation.

What are the key differences between PWM and PFM modes on the MAX17245ETESB+?

In PWM mode (FSYNC tied to BIAS or external clock), the MAX17245ETESB+ operates at fixed frequency across all loads - ideal for EMI-sensitive RF applications. In PFM mode (FSYNC grounded), it skips pulses at light loads to reduce switching losses, achieving 28µA quiescent current and >90% efficiency at 1mA. The MAX17245ETESB+ automatically transitions between modes based on FSYNC logic level, with no software or configuration required.

Does the MAX17245ETESB+ require an external Schottky diode, and why?

Yes, the MAX17245ETESB+ requires an external Schottky diode connected from LX to PGND, even though it integrates high-side and low-side MOSFETs. This is necessary to support the full 3.5A output current in PFM mode and ensure reliable operation under light-load conditions where the internal low-side MOSFET may not fully conduct. The diode also provides redundancy during fault conditions and improves efficiency at very low loads where synchronous rectification becomes less effective.

What thermal performance can be expected from the MAX17245ETESB+ in a standard PCB layout?

With the exposed pad (EP) soldered to a 4cm² solid PGND copper area on a 4-layer board, the MAX17245ETESB+ achieves θJA = 35°C/W. At 3.5A output and 14V input, typical power dissipation is ~1.2W, resulting in ~42°C junction-to-ambient rise - well below the +150°C max junction temperature. Thermal shutdown activates at +175°C with automatic recovery after cooling by 15°C, ensuring robust operation under sustained overload.