The Class D speaker amp's drive output stage utilizes high efficiency PWM drive (H or L) based on the output signal level. This results in low power loss and high efficiency (85-90%).In contrast, conventional analog amps feature Class AB output, requiring (among other things) a bias current. The result is low efficiency and high heat generation, requiring an external heat sink.

A number of amps are offered, from 2W types optimized for portable electronics to 20W Class products designed for LCD TVs.

Besides high efficiency and low heat generation, ROHM Class D speaker amps provide a number of advantages:

1. High fidelity (low noise, low distortion)
2. Popping noise eliminated (via soft mute function)
3. Multiple protection functions built in (preventing IC/speaker damage)

Based on the application a simple filter (i.e. ferrite beads, ceramic capacitor) can be used. For example, active speakers used for compact LCDs or iPod docks are products that use short speaker cables, while large-screen LCDs require longer speaker cables, resulting in the generation of unwanted radiation (EMI) requiring countermeasures (i.e. filters).

No. Applying solder between the backside and substrate will enable operation up to 20W+20W.

Of course.
Speaker output power is determined by Vcc (supply voltage) and the speaker load (in ohms). 20W output results from a supply voltage of 18V and a speaker load of 8Ω. For 10W output the conditions are: 13V Vcc and 8Ω speaker load.

It is the abbreviation of Bridge Tied Load.
It reverses the speaker both terminals to connect by using two amplifier circuits compared with a usual single amplifier. If without output coupling capacitor,it may has an advantage that output electric power quadruples.

Analog input.
Though it is encouraged to input to the noise with strong differential type,but it is also possible to input by single type, so please choose according to the system configuration.

Unnecessary.
The exclusive pop sound decrease circuit is installed in LSI, and a high-speed reset and pop sound less can be achieved.

Wafer Level CSP product (Min 1.5mm mouth) is best for the application as cellular phone etc that especially high density are demanded. Moreover, there are some space on PCB, and we also prepare usual plastic molding products with eight pins VSON packag for the customer who wants it.

The back of the package is a heat sink and is not connected internally to any pins. In order to maximize thermal dissipation, it should be connected to ground on the board.

This function prevents damage to the speaker due to excessive output. The circuit constants will vary based on the supply voltage, load, and other factors. Therefore, please inquire separately.

In order to measure the distortion of a Class D speaker amp, first the PWM output signal (digital) must be converted to analog.
Please connect the Class D amp output to the low pass filter in series and convert the analog signal.
Please refer to the technical notes for the low pass filter (LC filter) constants.
The converted analog signals are inputted into an audio analyzer, which can measure the amount of distortion.

LCD TVs are not only getting larger, they are becoming increasingly thin as well.
These design trends severely restrict both speaker placement and size. This results in a number of problems, including no sound or poor audio quality. In response to this ROHM developed the BM5446EFV that integrates a DSP along with a number of original audio functions, including:

1. A parametric equalizer that corrects speaker frequency characnteristics
2. P2Bass for powerful low-frequency playback
3. P2Treble that raises the sound stage for low-positioned speakers
4. P2Volume, designed to amplify sounds when sounds are compressed or small

The main function of the AV processor is for image processing. Therefore, the audio processing capabilites of most AV processors is insufficient. In addition, the processing capability may not be enough to prevent audio degradation in thinner speakers.

Yes

Not utilizing an output feedback circuit may adversely affect the PWM signal amplitude in the event of power supply fluctuation. Oftentimes, this results in speaker noise.
Conversely, integrating an output feedback circuit automatically corrects for supply voltage fluctuations, preventing speaker noise. In LCD TVs this circuit can share the +24V supply used for backlighting.