ROHM Semiconductor has developed USB host audio decoder ICs that are compatible to a variety of audio compression formats (BU9457KV: MP3, BU9458KV: MP3, WMA, AAC) and featuring high ESD resistance, which makes them suitable for car audio applications requiring specific surge characteristics as well as home and portable audio sets.
ROHM is offering a lineup of compact, monolithic USB host audio ICs that support a variety of file formats. However, until now there were no decoder ICs that integrate protection circuits designed to prevent malfunction due to noise from the effects of wiring and nearby devices. Previously, external countermeasures, such as terminal protection ICs and surge protection diodes and resistors, have been necessary, especially in applications exposed to harsh operating environments (car audio).
The BU9457KV and BU9458KV claims to fulfill these requirements by integrating an improved communication error recovery circuit in the USB interface block and provide high ESD resistance (6 kV at USB terminal/15 kV air/8 kV contact discharge) – meeting the requirements of the Electrostatic Discharge Immunity Test IEC 61000-4-2 Level 4 Standard. As a result, terminal protection ICs are no longer required, contributing to simpler designs and greater compactness.
In addition, incorporating interface hardware such as USB host and SD memory controllers, along with a D/A converter, sampling rate converter, compressed audio file decoder, file system, and system controller in a compact VQFP64 package (12 mm x 12 mm) makes it possible to play back music from USB memory and SD memory cards using a single chip. This facilitates compact application designs and allows simple command control (play, stop, fast forward, rewind) without the need for a microcontroller, enabling configuration of a USB host audio system by simply adding the chip to existing sets.
The combination of additional functionality and protective countermeasures makes the BU9457KV and BU9458KV ideal for a wide variety of sets, including devices that did not previously support audio output, such as massage chairs and alarm clocks, as well as applications requiring high reliability (car audio).
Key features of BU9457KV and BU9458KV:
- Built-in interface hardware, decoder, file system and system controller allow music playback from USB flash memory or SD memory cards
- 6 kV USB terminal ESD resistance
- Superior surge resistance: 15 kV (air discharge), 8 kV (contact discharge).
- Compact VQFP64 package (chip size: 12 mm x12 mm).
- The BU9457KV and BU9458KV are both pin- and control-software-compatible, simplifying upgrade.
The new series of USB host audio decoder ICs BU9457KV and BU9458KV are available now.