Analog Devices Inc./Maxim Integrated MAX17244ETESB+

Overview

MAX17244ETESB+ from Maxim Integrated is a 3.5V–36V input, 2.5A synchronous step-down DC-DC converter with integrated high-side and low-side MOSFETs, fixed 5V/3.3V or adjustable 1V–10V output, 28µA quiescent current, and 42V transient protection. It operates in PWM or PFM mode and supports external synchronization for EMI-sensitive RF power supplies.

For engineers reviewing the MAX17244ETESB+ datasheet, MAX17244ETESB+ pinout, MAX17244ETESB+ application, or MAX17244ETESB+ equivalent, key selection criteria include its 98% max duty cycle for dropout operation, 220kHz–2.2MHz resistor-programmable switching frequency, spread-spectrum EMI reduction, 180° out-of-phase SYNCOUT for cascaded supplies, and dual-mode FSYNC control for light-load efficiency optimization.

Technical Context

The MAX17244ETESB+ uses current-mode control with selectable PWM (fixed-frequency) or PFM (pulse-skipping) operation-enabling constant switching frequency across load range or ultra-low quiescent current at light loads. Its internal 5V BIAS LDO powers control circuitry until output regulation is achieved, then switches to OUT supply for efficiency.

It features cycle-by-cycle current limiting, thermal shutdown with 15°C hysteresis, overvoltage protection at 105% V_FB, and automatic LX slew-rate adjustment (4ns/8ns) based on operating frequency. The 180° SYNCOUT enables phase interleaving across multiple converters to reduce input ripple and improve thermal distribution.

Key Specifications

Pinout & Package

MAX17244ETESB+ is packaged in a 16-pin 5mm × 5mm TQFN with exposed pad (EP), optimized for thermal dissipation and compact layout. The exposed pad must be soldered to a large contiguous 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 LM61480RQR and TPS54560BQDDARQ1, the MAX17244ETESB+ uniquely combines PFM/PWM mode selection, 180° SYNCOUT for interleaving, and factory-enabled spread-spectrum - making it optimal for EMI-constrained, thermally dense, or battery-sensitive designs where dynamic efficiency and noise control are primary.

Availability

MAX17244ETESB+ is available at Aetrix Electronics and suitable for automotive infotainment, industrial IoT sensor nodes, and telecom remote radio units requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MAX17244ETESB+ 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 MAX17244ETESB+ belongs to Maxim's high-efficiency, wide-input synchronous buck converter family - engineered specifically for EMI-sensitive, wide-voltage, and low-quiescent-current power delivery in space-constrained embedded systems.

FAQ

What is the maximum input voltage transient rating for the MAX17244ETESB+?

The MAX17244ETESB+ supports 42V input voltage transients for durations ≤1 second, as specified in its Absolute Maximum Ratings. This protects against load-dump events in automotive 12V/24V systems without requiring external TVS diodes. The device remains functional during these transients and resumes normal regulation once input returns within 3.5V–36V operating range. This rating is validated per JEDEC standards and applies to both SUP and SUPSW pins.

Can the MAX17244ETESB+ operate in dropout mode, and what is its maximum duty cycle?

Yes, the MAX17244ETESB+ operates in dropout mode with a typical maximum duty cycle of 98%. When input voltage approaches output voltage, the controller extends on-time to maintain regulation - enabling stable 5V output even with 5.1V input. This behavior is critical for automotive cold-crank scenarios. The actual dropout voltage depends on output current, R_{ON_H}, and efficiency, but the 98% limit ensures minimal V_IN–V_OUT headroom under full load.

How does the FSYNC pin control operating mode in the MAX17244ETESB+?

The FSYNC pin selects between PFM and forced-PWM (FPWM) modes: connecting FSYNC to AGND enables PFM for lowest light-load current consumption, while connecting to BIAS or an external clock forces fixed-frequency PWM to eliminate frequency variation and minimize EMI. The MAX17244ETESB+ synchronizes to external clocks within one cycle and reverts to internal oscillator if clock is absent for >2 cycles - ensuring seamless mode transitions without output disturbance.

What is the purpose of the SYNCOUT pin on the MAX17244ETESB+, and how is it used?

The SYNCOUT pin on the MAX17244ETESB+ provides an open-drain 180° out-of-phase clock signal relative to the internal oscillator. It is used to cascade multiple MAX17244ETESB+ devices - for example, driving the FSYNC pin of a second converter - to achieve interleaved operation. This reduces input capacitor RMS current by ~30%, lowers thermal stress, and eases EMI filtering requirements in high-power multi-rail systems.

Does the MAX17244ETESB+ require an external Schottky diode, and why?

Yes, the MAX17244ETESB+ 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 full 2.5A output current across the entire operating range - particularly during light loads in PFM mode and transient conditions where the internal low-side FET alone cannot sustain conduction. The diode ensures reliable freewheeling path and prevents reverse current flow that could compromise regulation or cause instability.