The HT7178 is a very good DC-DC synchronous boost converter. No external MOSFET is required and no external diode is required. Compared to the synchronous boost chip on the market, he has a built-in 20V synchronous boost converter with a gate driver (to implement the load disconnect function). The peak current can reach 12A and the efficiency can reach 96%. Therefore, the HT7178 is very suitable for applications. In Bluetooth speakers, battery detection, electronic cigarettes, highlight flashlights, USB type-c PD, large-size panel door-level drivers and other occasions.
Shenzhen Yonghe Kang Technology Co., Ltd. combined with customer's actual program, successfully applied to 3.7V boost to 9V (8W & TImes; 2 output), 3.7V boosted to 12V (20W output) high-end Bluetooth audio; 7.4V boosted to 15V ( 40W output), 12V boost to 20V (60W output) square dance audio; electronic cigarette and other cases.
two. product description1. Product Features
1. The input voltage range of the HT7178 is 2.7V to 15V, and the output voltage range is 4.5V to 20V. The chip integrates two low-resistance power MOSFETs: an 11mΩ switching FET and a 13mΩ rectifier FET, using a fixed-frequency peak current mode control with integrated ramp compensation. The HT7178 PFM and PWM modes are selectable to match different applications and improve efficiency.
2.HT7178 integrated undervoltage protection, overvoltage protection, over temperature protection. The undervoltage lockout circuit prevents circuit failure at low voltage and overdischarge of the input resistor. The voltage is below the corresponding threshold and the chip shuts down. The voltage is higher than the corresponding threshold, the chip is turned on; if the output voltage is higher than 22V (typ), the overvoltage protection circuit starts to operate, the chip stops working until the output voltage drops below the threshold; when the internal junction temperature of the chip is higher than 150°C, Over-temperature turn-off protection starts and the chip stops working until the internal junction temperature of the chip is reduced to 130°C. This function can effectively prevent the chip from being damaged. The HT7178 is available in a 4.5mm x 3.5mm DFN20 package with excellent thermal dissipation. The pin function is compatible with the TPS61088.
2. Application characteristics
1.HT7178 pin bitmap
2.HT7178 typical application diagram
From the above figure, we can see that there are few external devices required. The chip also provides a separate pin pin DIS to drive the external FET (P-FET) on the load output, which completely disconnects the input and output when the device is turned off or the output is short-circuited. At startup, the external P-FET switch is controlled by an internal current source. In the event of a shutdown or output short-circuit, isolate the output from the input side as shown in the following figure:
3.HT7178 DEMO board circuit diagram
4.HT7178 DEMO board main performance index
5.HT7178 DEMO Board BOM
6. Figure HT7178 DEMO board PCB top floor design
7.HT7178 DEMO PCB bottom layer design
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