HT81696 is a stereo class D audio power amplifier with built-in boost. It supports single-cell lithium battery, double-cell lithium battery in series, 5V, 12V and other inputs. The boosted voltage is supplied to the power amplifier, which supports dual-channel stereo BTL. output as well as parallel PBTL mono output. The built-in boost circuit of the HT81696 can set the boost value through the FB pin to meet different output power requirements. It also adjusts the switch peak current limit with an external resistor.

Author: Shenzhen Yongfukang Technology Co., Ltd.

The power supply of outdoor square dance drawbar speakers has been mainly using lead-acid batteries, the output voltage of lead-acid batteries is 9.5V-14.6V, and the direct-supply audio amplifier chip can output 20W/channel continuous power. However, lead-acid batteries have inherent defects such as large volume, unenvironmental protection, and low cycle charging times. Outdoor Bluetooth audio requires portability. Lithium batteries are gradually replacing lead-acid batteries due to their advantages such as energy density, cycle charging times, and environmental protection. Power supply. Due to the difference between the batteries, the multi-cell lithium battery has to consider the balance and charging cost to limit its application and popularization. The series power supply of two lithium batteries has become the main choice for outdoor speaker manufacturers since a period of time.

However, the output voltage of two 18650 lithium batteries in series is 6V-8.4V. In the case of direct battery supply, each channel can only provide a power output of 7W/4 ohms, which is obviously smaller than that of lead-acid batteries. How to provide more than 20W/channel power output in two lithium battery power supply? It has become the main problem that has plagued Electronic engineers for a long time. At this stage, the solution of boost + power amplifier chip is mainly used, which has many peripheral components and complicated PCB design. Shenzhen Yongfukang Technology Co., Ltd. summarizes the pain points of market application, and now vigorously promotes a 2X30W dual channel/50W mono class D audio amplifier chip-HT81696, which can be widely used in square dance speakers, smart speakers, portable Bluetooth speakers, etc. In the field of products, with its advantages of high efficiency and high power, simple application and high cost performance, it has accelerated the realization of the mainstream power supply method in the field of outdoor pull rod square dance speakers, replacing lead-acid batteries with lithium batteries.

HT81696T measured power curve

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

Overview

HT81696 is a stereo class D audio power amplifier with built-in boost. It supports single-cell lithium battery, double-cell lithium battery in series, 5V, 12V and other inputs. The boosted voltage is supplied to the power amplifier, which supports dual-channel stereo BTL. output as well as parallel PBTL mono output. The built-in boost circuit of the HT81696 can set the boost value through the FB pin to meet different output power requirements. It also adjusts the switch peak current limit with an external resistor. In addition, the HT81696 integrates filter-free modulation technology, which can directly drive the speaker. The built-in shutdown function minimizes the standby current. It also integrates output over-current protection, on-chip over-temperature protection, input power supply under-voltage abnormal protection, rise Voltage and overvoltage protection and other functions.

characteristic

• Output power (fIN=1kHz, RL=4Ω, BTL)
• Dual lithium battery 8.4V: 2×30W (VOUT=16V, THD+N= 10%)
• Single lithium battery 3.7V: 2×10W (VOUT=9V, THD+N = 10%)
• Output power (fIN=1kHz, RL=3Ω, PBTL)
• Dual lithium battery 7.2V: 52W (VOUT=17V, THD+N= 10%)
• Single lithium battery 3.7V: 15W (VOUT=9V, THD+N = 10%)
• Output power (fIN=1kHz, RL=4Ω, PBTL)
• Single lithium battery 3.7V: 20W (VOUT=12V, THD+N = 10%)
• VBAT supply range: 2.7V to VOUT
• Class D amplifier with spread spectrum function
• Built-in boost circuit: adjustable boost value and boost current limit
• Protection function: overcurrent/overheating/undervoltage abnormal/overvoltage protection function
• Lead-free halogen-free package, ETSSOP28

application

Smart Speakers, Wireless Speakers, Portable Speakers, 2.1-Channel Small Speakers, Rod Speakers, Portable Game Consoles

HT81696 Application Information

1. HT81696T pinout

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

2. HT81696T pin description

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

3. Schematic diagram of HT81696T DEMO board

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

4. HT81696T DEMO board PCB top-level design

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

5. HT81696T DEMO board PCB bottom design

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

6. HT81696T DEMO board patch picture

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

7. HT81696T DEMO board bill of materials

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

8. Physical map of HT81696T DEMO board

HT81696 Two-cell lithium battery 7.4V built-in boost 2X30W dual channel/50W mono class D audio power amplifier IC solution

The Links:   2MBI300HH-120 LP150X10-A3K2