FEATURE

・Anti-Clipping Function (ACF)

・Filter-less Modulation, Eliminating Output Filter

・Output Power

5.5W (VBAT=4.2V, PVDD = 6.5V, RL=4Ω,

THD+N=10%)

3.0W (VBAT=4.2V, PVDD = 6.5V, RL=8Ω,

THD+N=10%)

・Power Supply

-Boost Input VBAT：2.5V to 5.5V

-Boost Output PVDD：VBAT to 7.0V

・Adjustable BOOST Output Voltage

・Class AB / Class D

・Over Current Protection, Thermal Protection,

Low voltage malfunction prevention function

included

・Pb-Free Packages , SOP8L-PP

APPLICATIONS

・Bluetooth Speakers ・Portable Speakers

・2.1 Channel Speakers ・Megaphone

・iphone/ipod/ipod docking ・MP4/GPS

・Tablet PC/Note Book ・Smart Phones

・LCD TV/Monitor ・Portable Gamers

GENERAL DESCRIPTION

HT8691 integrates a boost converter with a

filter-less stereo class D audio power amplifier to

provide 5.5W continuous power into a into a 4Ω

speaker when operating from a Li-battery voltage

boosted to 6.5V. Meanwhile, the boost output

voltage is adjustable.

HT8691 features Anti-Clipping Function (ACF)

which detects output signal clip due to the over

input signal and suppresses the output signal clip

automatically. Also, the ACF function can adapt the

output clip caused by power supply voltage down

with battery. It can significantly improve the sound

quality, creating a very comfortable musical

enjoyment, and to protect the speakers from

overload damage. It also supplies ACF OFF mode.

Class AB amplifier mode is also available for

HT8691. Once the EMI Interference from class D

and Boost Converter becomes an annoying

problem, HT8691 can be changed into Class AB

mode.

HT8691 has a filter-less modulation circuit

which directly drives speakers while realizes low

distortion and low noise characteristics. Thanks to

filter-less, circuit design with fewer external parts

can be made in portable applications.

HT8691 has the independent Shutdown

function which can minimize the power

consumption at standby and MUTE function. As for

protection function, over current protection function

for speaker output terminals, over temperature

protection function, and low supply voltage

malfunction preventing function are also prepared.