Audio Amplifier with Jack Detection

The MAX97236 is an audio amplifier with volume control and microphone preamplifier intended for use in portable audio systems employing a headphone jack. The audio circuit is powered from a single, dual-mode charge pump, allowing the output signals to be ground referenced, and eliminating the need for large and expensive DC-blocking capacitors. The configuration of a 3.5mm jack is determined by autoconfigure circuitry. The IC’s functional blocks are auto-enabled after the configuration of the jack is determined.

The audio amplifier is powered from a single 1.8V power supply that reduces overall power consumption. The microphone preamplifier and bias are powered from a separate power-supply input accommodating bias voltages that are greater than 2.4V.

The automatic jack detection determines when a 3.5mm plug is inserted into the system jack and determines the configuration of the installed load. The configuration of the load is then reported to the system through the I2C interface. Multiple popular jack and load configurations are detectable with this scheme. The IC detects headsets, headphones, and A/V cables.

The headphone amplifier is capable of over 35mW into 16Ω. The device is available in a small, 25-bump WLP package with a 0.4mm pitch and is specified over the extended -40°C to +85°C temperature range.

Applications

* Mobile Handsets * Notebooks * Portable Gaming Devices * Smartphones * Tablets

* 30mW Headphone Amplifier Employs Second- Generation DirectDrive® with Dual-Mode Charge-Pump Architecture

* Automatic Jack Detection Circuitry

* Microphone Amplifier and Bias

* 1.8V Power Supply

* 2.4V to 3.6V Microphone Power Supply

* Headphone Amplifier Volume Control

* Decodes Data from a Passive Multibutton Headset Remote Control

* 25-Bump, 2.4mm x 2.3mm, 0.4mm Pitch WLP