MAX9725DETC+T

Overview

The MAX9725DETC+T is a fixed-gain stereo headphone amplifier from the DirectDrive series, manufactured by Analog Devices Inc./Maxim Integrated. It operates on a single 0.9V to 1.8V supply and delivers up to 20mW per channel into a 32Ω load with 0.006% THD+N. The device features a fixed voltage gain of -4V/V, an inverting charge pump for ground-referenced outputs, and low-power shutdown mode reducing current to 0.6µA. It includes integrated click-and-pop suppression, short-circuit protection, and ±8kV ESD protection. The component is housed in a 12-pin thin QFN package (4mm x 4mm x 0.8mm) and operates over an extended temperature range of -40°C to +85°C.

Feature Summary

• DirectDrive architecture eliminates large DC-blocking output capacitors by generating an internal negative supply via an inverting charge pump.
• Fixed voltage gain of -4V/V reduces external component count compared to adjustable variants.
• Integrated comprehensive click-and-pop suppression circuitry prevents audible transients during power-up and shutdown.
• Low quiescent current consumption of 2.1mA supports operation from a single AA or AAA battery cell.

Applications

• Portable audio equipment
• Cellular phones
• MP3 players

Procurement Notes

Verify the specific suffix 'ETC' corresponds to the 12-pin Thin QFN package configuration as indicated in official documentation. Confirm that the '+TG45' designation aligns with lead-free and RoHS compliance requirements for your manufacturing process. Ensure the fixed gain variant matches the system design needs, as this part does not support external feedback resistor adjustment.

Selection Notes

Select this model when a fixed high gain of -4V/V is required for direct drive applications without external feedback networks. Consider the 12-pin Thin QFN package for space-constrained designs where board area is limited. Verify that the single-supply voltage range of 0.9V to 1.8V aligns with the available battery or power source in the target application.

Part Context

The MAX9725 family includes variants with different fixed gains (-2V/V, -1.5V/V, -1V/V) and an adjustable gain version (MAX9725E). The MAX9725DETC+T specifically denotes the -4V/V gain option packaged in a 12-pin Thin QFN format. Other family members may utilize UCSP packages or offer different gain settings to accommodate various input signal levels and impedance matching requirements.

Replacement Considerations

Public confirmed substitute part numbers are not provided in the source material.

FAQ

How does the DirectDrive architecture benefit the design?

It generates a ground-referenced output using an internal charge pump, eliminating the need for large, expensive DC-blocking capacitors on the output, which saves board space and improves low-frequency response.

What is the function of the SHDN pin?

The SHDN pin controls the low-power shutdown mode. Driving it low disables the amplifiers and charge pump, reducing supply current to approximately 0.6µA.