MAX9895AETL+

Audio Amplifiers Overview

The MAX9895AETL+ is a complete audio subsystem for active noise-cancelling stereo headsets, manufactured by Analog Devices Inc./Maxim Integrated. It integrates microphone preamplifiers, an analog sound processing block, and capacitorless headphone amplifiers. The device operates on a supply voltage range of 2.7V to 4.5V and delivers 33mW into a 16Ω load. It features a feed-forward architecture with three operational modes: ANC on, PTL, and ANC off. The component utilizes an I2C interface for gain adjustment and mode selection, housed in a 40-pin TQFN-EP package.

Audio Amplifiers Feature Summary

• Integrates ultra-low noise microphone preamplifiers with programmable gain via I2C or external resistors.
• Features a feed-forward active noise-cancelling architecture that generates compensation signals to attenuate ambient noise.
• Includes capacitorless stereo headphone amplifiers that eliminate the need for large output-coupling capacitors.
• Supports Push-to-Listen (PTL) mode for temporarily bypassing noise cancellation to hear surroundings.

Audio Amplifiers Applications

• Noise-Cancelling Headphones/Headsets
• Headsets for Mobile Communication
• Mobile Phones
• Portable Gaming Devices

Audio Amplifiers Procurement Notes

Verify the specific suffix ETL corresponds to the 40-pin TQFN-EP package variant when sourcing. Confirm RoHS compliance status as indicated by the plus sign in the part number. Ensure the design supports the required I2C bus configuration or hardware mode pinning, as the SCL pin determines the control interface availability.

Audio Amplifiers Selection Notes

Select this component for designs requiring a fully integrated stereo audio solution with active noise cancellation capabilities. It is suitable for battery-powered portable devices due to its low quiescent current and single-supply operation. Consider the available signal processing pins if custom analog filtering is required for specific headset acoustic characteristics.

Audio Amplifiers Part Context

This component belongs to the MAX9895 family of audio subsystems designed specifically for stereo headset applications. It consolidates multiple discrete audio stages into a single IC to reduce board space and component count. The ETL+ designation identifies the lead-free, RoHS-compliant version packaged in a thermally enhanced quad flat no-lead format.

Audio Amplifiers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

Audio Amplifiers FAQ

How is the microphone gain adjusted?

Microphone gain can be adjusted using an I2C interface connected to a microcontroller or by modifying external feedback resistors in the preamplifier stage.

What is the function of the PTL mode?

Push-to-Listen (PTL) mode connects the microphone preamplifier directly to the headphone amplifier, bypassing noise cancellation and attenuating line-input signals to allow the user to hear surroundings without removing headphones.

Why does the headphone amplifier not require coupling capacitors?

The amplifier uses a high-efficiency charge pump to create an internal mid-bias supply voltage (VMID), allowing outputs to be connected directly to headphones without DC-blocking capacitors.