MAX9737ETG+

Audio Amplifiers Overview

The MAX9737ETG+ is a mono 7W Class D audio power amplifier manufactured by Analog Devices Inc./Maxim Integrated. It operates from an 8V to 28V supply voltage and delivers up to 13W output power into a 4Ω load at 10% THD+N. The device achieves up to 88% efficiency at a 12V supply, eliminating the need for heatsinks in many applications. It features spread-spectrum modulation to minimize EMI, allowing compliance with CE limits using only small ferrite beads and capacitors on speaker cables up to 1m. Key electrical parameters include an 80dB PSRR, <1µA shutdown current, and a switching frequency of 300kHz with ±4kHz spread-bandwidth. The unit is housed in a 24-pin TQFN-EP package (4mm x 4mm) and operates within a temperature range of -40°C to +85°C.

Audio Amplifiers Feature Summary

• Filterless operation enabled by spread-spectrum modulation that reduces radiated emissions without requiring large output LC filters.
• Comprehensive click-and-pop suppression circuitry with precharge functionality ensures noise-free startup and mode transitions within 10ms.
• High 80dB power-supply rejection ratio (PSRR) allows stable performance directly from unregulated power sources.
• Integrated thermal and output current protection safeguards the device against short circuits and excessive heat.

Audio Amplifiers Applications

• 2.1 Notebook PCs
• LCD/PDP/CRT Monitors
• PC Surround Speakers
• MP3 Docking Stations

Audio Amplifiers Procurement Notes

Verify the component marking matches the standard Maxim/Analog Devices identification for the MAX9737ETG+. Confirm the package type is the 24-pin TQFN with an exposed thermal pad. Ensure the part number suffix indicates lead-free/RoHS compliance as specified in the official documentation. Cross-reference the manufacturer date code and lot number against authorized distributor records to guarantee authenticity and traceability.

Audio Amplifiers Selection Notes

Select this amplifier for single-channel audio systems requiring high efficiency and minimal board space. It is suitable for designs where avoiding external output inductors is critical for cost or size constraints. The wide 8V to 28V input range supports various battery and regulated supply architectures. Consider the internal gain structure and required external passive components for setting the desired cutoff frequency and amplification level.

Audio Amplifiers Part Context

This component belongs to the Maxim Integrated line of Class D audio amplifiers, now under Analog Devices Inc. It is designed as a thermally efficient solution for portable and desktop audio equipment. The device integrates a charge pump, internal regulators, and an input operational amplifier stage. It replaces older linear amplifiers or filter-dependent Class D designs by offering comparable audio quality with significantly reduced power dissipation and electromagnetic interference.

Audio Amplifiers Replacement Considerations

Check for direct pin-compatible upgrades within the same product family if higher channel counts or different supply voltages are needed. Verify that any substitute maintains the 24-pin TQFN-EP footprint and exposed pad thermal requirements. Ensure the replacement supports the specific 8V to 28V operating range and meets the same EMI and efficiency standards for the target application.

Audio Amplifiers FAQ

How does the MAX9737 achieve filterless operation?

It uses spread-spectrum modulation that varies the switching frequency randomly by ±4kHz around the 300kHz center point. This spreads the EMI energy over a wider bandwidth, reducing peak spectral components and allowing compliance with limits using only small ferrite beads and capacitors.

What is the purpose of the PC pin?

The PC (Input Capacitor Precharge) pin connects between the input resistor and the input coupling capacitor. It enables the precharge circuitry to manage the voltage across the input capacitor during startup, ensuring click-and-pop suppression occurs within 10ms.

Can the MAX9737 operate from a single supply?

Yes, it operates from a single PVDD supply ranging from 8V to 28V. The internal circuitry, including the charge pump and regulators, is powered from this main supply rail.