The MAX4298 and MAX4299 are audio system ICs designed for single +5V applications. The MAX4299 features a stereo headphone driver, a microphone amplifier, and a +3.3V linear regulator; the MAX4298 features a stereo headphone driver. The MAX4298/MAX4299 are designed specifically for harsh digital environments where board space is at a premium and the digital power supply is noisy. The design uses innovative design techniques to achieve ultra-high power-supply rejection across the audio signal band while, at the same time, delivering a high-current Rail-to-Rail output drive capability. The chip is designed to drive highly capacitive loads that may be encountered when driving long cables to a remote load such as desktop/notebook headphones or speakers. These devices are fully compliant with PC99 standards.
The amplifiers exhibit 115dB of DC power-supply rejection and 80dB at 100kHz. The output amplifiers are capable of driving a 1.5VRMS signal into a 10-kilohm load with 0.0008% THD+N. They can also drive 32Ω headphones to 1.2VRMS with 0.02% distortion. At +3.3V, the linear regulator can output 100mA of current. The MAX4298 is available in a tiny 10-pin µMAX® while the MAX4299 is available in the space-saving 16-pin TSSOP package.
Key Features
Applications/Uses
Audio System IC (MAX4299)
Ultra-High PSRR Stereo Headphone Driver
Ultra-High PSRR Microphone Amp
100mA, 3.3V Linear Regulator
93dB typ PSRR at 20kHz Operates Directly from Noisy Digital Supplies
Clickless/Popless Power Up, Power Down, Mute and Unmute
PC99 Compliant Output Drivers:
Better than 1VRMS Output into 16Ω Load and 1.5VRMS and 0.0008% THD+N into 10kΩ Load