Single-chip bridge links audio accessories to Apple iOS environment

April 01, 2015 // By Graham Prophet
Silicon Labs has designed a digital audio bridge chip and evaluation kit designed to simplify the development of accessories for iOS devices. The CP2614 interface IC provides a turnkey audio bridge solution for a wide range of Made for iPod/iPhone/iPad (MFi) devices that use the all-digital Lightning connector.

The CP2614 bridge chip and MFI-SL-CP2614-EK evaluation kit provide a cost-effective development platform for iOS accessory developers, enabling fast time to market through fixed-function MFi support. The CP2614 solution requires no firmware development, which helps developers get up and running quickly with their MFi accessory designs.

Developers simply select their customisation options with an easy-to-use GUI-based configuration tool. Target applications include audio accessories such as guitar and microphone recording dongles, audio docks and headphones. The CP2614 IC also provides built-in support for communication between iOS applications and accessory hardware, enabling a broad array of IoT accessories that operate with a companion iOS app.

The CP2614 bridge chip manages and minimises power consumption, achieving ultra-low power in both active and idle modes. The CP2614 IC’s energy efficiency suits it to device-powered accessories. The CP2614 also includes an integrated 5V low drop-out (LDO) regulator, which reduces bill of materials (BOM) cost and footprint for self-powered accessories. The highly integrated CP2614 device operates without an external crystal or EEPROM, storing all configuration options on chip. The crystal-less architecture and integrated EEPROM further reduce BOM cost as well as printed circuit board (PCB) space.

The CP2614 audio bridge chip supports 24-bit unidirectional and 16-bit bidirectional digital audio streaming, enabling developers to create high-quality, high-performance “prosumer”-class audio accessories. The CP2614 can establish a communications channel with an iOS application, enabling the app to interact directly with the accessory hardware through general-purpose input/output (GPIO) read/writes and access to the UART for custom data flow. The GPIO can be configured for button input and LED output and accessed remotely from an iOS app or used to control audio playback.

“To succeed in today’s competitive iOS accessory market, developers need turnkey solutions – silicon, firmware and evaluation kits – that help them to simplify their designs, reduce power and cost, and speed time to market,” said Daniel Cooley, vice president and general manager of Silicon Labs’ microcontroller and