Since 2017, outdoor Bluetooth speakers (including 2-inch / 4-inch speakers, portable Bluetooth speakers and 6-inch / 8-inch outdoor pull rod speakers) have become the fastest-growing speaker category. This kind of speaker is mainly powered by a single lithium battery. Generally, the built-in boost audio power amplifier chip is selected. The power amplifier chip without inductive boost of charge pump is the most common. The power output is 3 ~ 5W / 4 Ω up and down to 6.3V, and the power amplifier chip with inductive boost boost is about 7V, and the power output is 6 ~ 8W / 3 Ω. Its performance basically meets the application of indoor and outdoor scenes. However, higher power and better sound quality have always been the eternal pursuit of the speaker market.
Shenzhen yongfukang Technology Co., Ltd. complies with the needs of sound quality and power upgrading in the pull rod speaker and Bluetooth small speaker market, and promotes a single section and double section lithium battery power supply with built-in adaptive dynamic boost 20W mono class D power amplifier ic-ht81293. Using the latest BCD process, the internal boost module is boosted to 12V, which has been in line with the voltage of lead-acid battery / three lithium batteries in series, realizing the ultimate power output of single lithium battery power supply.
The unique adaptive dynamic boost of ht81293 can adjust the output voltage of the power module according to the required output power of the chip, which greatly improves the life time of lithium battery; Its input current limiting function can set the maximum input current to avoid the restart of the main control due to the instantaneous voltage drop of lithium battery (considering the power requirements, it is generally recommended to set the maximum input current to about 8a); It can realize the switching of various modes such as off, on, anti broken sound on / off through a master control IO port, so as to save the resources of Bluetooth master control; 2-gear anti breaking mode, AcF1 wide dynamic volume shock mode is suitable for outdoor pull rod speakers, and ACF2 high fidelity and low distortion mode is suitable for portable Bluetooth speakers. The two modes can present different styles of sound quality only by changing the peripheral resistance.
When the built-in audio power amplifier is powered by lithium-ion power amplifier (thn + 294%), the output power of HTD = 10 Ω is a continuous load.
Ht81293a has built-in dynamically adjustable boost, which can provide a voltage suitable for different output power to class D power amplifier, which can greatly improve the system efficiency and prolong the battery life. Ht81293f has built-in fixed boost and provides a fixed 9V or 12V boost to class D power amplifier. Ht81293 can be configured with boost current limit to prevent excessive current spikes.
The biggest feature of ht81293 is the anti clipping distortion (ACF) output control function, which can detect and suppress the clipping distortion (broken sound) of the output signal caused by the excessive amplitude of the input music and voice signal. It can also adaptively prevent the output clipping caused by the drop of boost voltage, significantly improve the sound quality and create a very comfortable listening enjoyment, And protect the speaker from overload damage. Ht81293 provides two ACF modes for different music experiences and ACF off mode. Ht81293 has advanced spread spectrum function to suppress EMI. The gain of ht81293 is 32dB. In addition, ht81293 integrates the functions of output overcurrent protection, on-chip over-temperature protection, boost and overvoltage protection, etc.
・ anti clipping distortion function (anti breaking, anti clipping function, ACF)
・ spread spectrum technology
・ output power:
18W （VBAT=3.7V， RL=4Ω， THD+N=10%， fIN = 1kHz）
16W （VBAT=3.7V， RL=4Ω， THD+N=1%， fIN = 1kHz）
・ Vbat power supply range: 3.0V to 12V, taking into account the application of single and double lithium batteries
・ high efficiency class H boost function – boost rail of adaptive power amplifier power to prolong battery playback time (ht81293a) – the maximum current limit can be adjusted to effectively prevent battery from being pulled dead
・ protection function: overcurrent / overheating / overvoltage protection function
・ lead free package, esop16
・ Bluetooth / Wi Fi speaker ・ portable speaker ・ smart speaker ・ smart home
Ht81293 dynamic boost waveform:
Ht81293 application information
1. Ht81293 pin bitmap
2. Ht81293 pin description
3. Schematic diagram of ht81293demo board
4. Top level design drawing of ht81293demo board PCB
5. Bottom PCB design drawing of ht81293demo board
6. Ht81293demo board patch diagram
7. Material list of ht81293demo board
8. Front of 3D layout of ht81293demo board
9. Reverse side of 3D layout of ht81293demo board
10. Physical drawing of ht81293 demo board