Renesas introduces amplifier for flat-screen TVs

It is intended for use in thin flat-screen televisions employing LCD or plasma display panels.

The 24-bit audio DSP performs signal processing and amplifies the result with a digital amplifier to deliver stereo output to two speakers at up to 15W for each channel.

Thin flat-screen televisions typically require detailed tuning of their audio systems for different markets and screen sizes.

The main DSP, which handles tasks such as surround processing and decoding, usually performs this tuning in the preceding stage of the digital amplifier.

This imposes a significant processing load.

In the R2J15116FP, the built-in audio DSP does the processing for the volume control and the parametric equaliser for optimising the speaker characteristics.

This reduces the load on the main DSP and makes it possible to generate a more varied and higher quality sound for video applications.

The R2J15116FP also achieves better audio signal performance and quality than conventional digital volume control implemented using a DSP.

It does this by using an intelligent volume function that offers higher resolution when switching the volume level for smoother volume level transitions.

The R2J15116FP uses a feedback circuit to stabilise the output level when the power supply voltage fluctuates.

The R2J15116FP also features a two-band tone control, a loudness function for low- and high-range expansion compensation, a power limiter function that allows setting of a user-defined maximum output level and a dynamic range control (DRC) function that lowers the signal amplitude without distortion at high volume levels and raises it at low volume levels.

Settings for all of these functions can be made flexibly from the MCU via the I2C bus.

Protection functions include detection of overcurrent, overheating and low voltage, as well as a feature that provides warning in advance of overheating.

This automatically lowers the volume to prevent the temperature from rising to a dangerous level.

Additional functions include PLL unlock detection, which enhances the safety of signal input to the amplifier, and input signal error detection.

The R2J15116FP uses a compact 48-pin HTQFP package and requires no heat sink.

The device comes in a 7 x 7mm package.