Analog Devices Inc./Maxim Integrated MAX17242ETPB+T

Overview

The MAX17242ETPB+T from Maxim Integrated is a 2A, synchronous step-down DC-DC converter with integrated MOSFETs, operating from 3.5V to 36V input and delivering fixed 3.3V/5V or adjustable 1V–10V output. It features 15µA quiescent current in standby, 93% peak efficiency, and 2.2MHz switching frequency with spread-spectrum EMI reduction-used in industrial power supplies and distributed point-of-load regulation.

For engineers reviewing the MAX17242ETPB+T datasheet, MAX17242ETPB+T pinout, MAX17242ETPB+T application, or MAX17242ETPB+T equivalent, key selection considerations include its 20-pin TQFN package, 99% max duty cycle for dropout operation, PFM/PWM mode control via FSYNC, ±1% FB accuracy for adjustable outputs, and integrated 60mΩ/35mΩ high-side/low-side MOSFETs.

Technical Context

This current-mode buck regulator uses internal high-side (60mΩ typ) and low-side (35mΩ typ) MOSFETs, enabling fixed-frequency PWM or pulse-frequency modulation (PFM) operation selected by the FSYNC pin. Its 1V feedback reference and ±1% FB accuracy support precise output programming across 1V–10V.

The device integrates a 5V BIAS linear regulator (4.7–5.4V), PGOOD open-drain output with 95%/92.5% VFB thresholds, and thermal shutdown at 175°C with 15°C hysteresis. Spread-spectrum modulation (±3% around FOSC) is enabled via the SPS pin and disabled during external clock synchronization.

Key Specifications

Pinout & Package

MAX17242ETPB+T is housed in a 20-pin, 5mm × 5mm TQFN package with exposed pad (EP), rated for –40°C to +85°C operation and optimized for thermal dissipation via EP-to-PGND connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQWR and TPS54240DGQR, the MAX17242ETPB+T provides superior integration (integrated MOSFETs, BIAS LDO, PGOOD, spread spectrum), tighter feedback accuracy (±1%), and significantly lower standby current (15µA vs 12µA/145µA), making it optimal for compact, low-power, EMI-sensitive industrial and automotive point-of-load applications.

Availability

MAX17242ETPB+T is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and programmable logic controller I/O modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX17242ETPB+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 industrial, automotive, and communications markets.

The MAX17242/MAX17243 product line delivers highly integrated, wide-input synchronous buck converters targeting space-constrained, low-quiescent-current applications where reliability under voltage transients and EMI compliance are critical.

FAQ

What is the maximum duty cycle supported by the MAX17242ETPB+T, and how does it benefit dropout operation?

The MAX17242ETPB+T supports up to 99% duty cycle, allowing continued regulation when input voltage drops close to the output voltage-critical during automotive cold-crank events or brownouts. This high-duty-cycle capability eliminates need for pre-regulators in wide-input industrial systems, simplifying power architecture while maintaining output stability down to V_IN ≈ V_OUT + (I_OUT × R_{ON_H})/0.98.

How does the MAX17242ETPB+T achieve 15µA quiescent current, and in which operating modes is this realized?

The MAX17242ETPB+T achieves 15µA typical quiescent current in standby mode (no load, V_OUT = 3.3V or 5V, FSYNC = 0V) by dynamically disabling nonessential bias circuits and entering PFM operation. This ultra-low I_Q is maintained across the full –40°C to +85°C temperature range and enables multi-year battery life in always-on sensor nodes and remote monitoring devices powered by the MAX17242ETPB+T.

Can the MAX17242ETPB+T be synchronized to an external clock, and what are the frequency tolerance limits?

Yes, the MAX17242ETPB+T can be synchronized to an external clock applied to the FSYNC pin. The device locks to external frequencies within ±20% of its internal oscillator frequency (e.g., for a 2.2MHz internal clock, sync range is 1.76MHz–2.64MHz). If the external clock deviates beyond this window, the MAX17242ETPB+T reverts to internal oscillation after two missed cycles-ensuring robust operation during clock instability.

What is the role of the BIAS pin on the MAX17242ETPB+T, and why is its bypass capacitor critical?

The BIAS pin on the MAX17242ETPB+T outputs a regulated 5V supply (4.7–5.4V) powering internal analog and logic blocks. A minimum 2.2µF ceramic capacitor must be placed between BIAS and AGND to stabilize this LDO and prevent oscillation or startup failure. Without proper bypassing, the MAX17242ETPB+T may exhibit erratic enable behavior, PGOOD glitches, or inability to regulate-especially under dynamic load transitions.

Does the MAX17242ETPB+T support adjustable output voltages, and what is the accuracy specification for that mode?

Yes, the MAX17242ETPB+T supports output voltages from 1V to 10V using an external resistive divider from OUT to FB to AGND. In this mode, the device guarantees ±1% feedback voltage accuracy (V_FB = 1.00V ±10mV), translating to ±1% output accuracy when R_FB2 ≤ 500kΩ and layout parasitics are minimized-enabling precision rails for ADC references, FPGA cores, and low-voltage microcontrollers.