MAX9700CEUB+

MAX9700CEUB+ application field and working principle

The MAX9700CEUB+ is an audio amplifier in the linear audio amplifiers category, designed to maximize single-ended mono audio output levels with minimal quiescent current. This device is ideally suited for Class B speaker and bridge-tied amplifiers.

The MAX9700CEUB+ is capable of providing up to 3.2W of output power in 8Ω BTL (bridge-tied load) configuration, thus making it an ideal solution for smartphone speakers, hands-free car kits, and other audio applications requiring high-efficiency amplification.

Operating Principle and Features

The MAX9700CEUB+ operates using a single-ended Class AB structure, which provides superior performance over Class D target applications. This amplifier employs an inverted feedback loop to control the voltage gain, and this feedback is adjustable using external resistors. In addition, the output stage features an NMOS output pair, thus providing improved PSRR performance over conventional Class B amplifier solutions.

The MAX9700CEUB+ also provides various protection features in order to protect the output device from thermal effects, dc-offset related issues, and short circuit conditions. Furthermore, the device provides external current-limit and short-circuit sensing with automatic input mute capability, enabling the device to safely recycle when necessary.

External Components and Layout

The MAX9700CEUB+ requires a few external components in order to operate correctly, including the input resistor, the current-sense resistor, the external short-circuit sensing resistor, and the decoupling capacitors. In order to maximize the performance of the device, it is important to ensure that these components are layout correctly. For example, the input resistor should be located close to the device’s input pins, and the current-sense resistor should be placed as close as possible to the output pins. Additionally, the ac load should be connected to the appropriate pins, so as not to interfere with the performance of the device. Also, it is important to provide proper ground plane for the amplifier, as this will reduce radiated noise and EMI emission.

Conclusion

The MAX9700CEUB+ is an ideal solution for driving single-ended mono-audio signals with low quiescent current. Through its inverting feedback loop and adjustable gain, the device can provide superior audio performance while also offering various protection features. The external components must be carefully laid out and connected to the appropriate pins in order to maximize the performance of the device. Finally, providing a proper ground plane is important in order to reduce radiated noise and EMI emission.