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Other Parts Discussed in Thread: LM5176, LM5176EVM-HP



    BUCK_BOOST - 副本.pdf为了降低芯片的发热情况,将VIN管脚通过10Ω接至外部辅助电源,当外部辅助电源调整为7.5V时,断开R2、R3、R4、R5, 接入DC输入后,VCC管脚电压只有6V多点,调整辅助电源至9V左右后,VCC管脚电压达到7.35V,此时状态为,电源不工作,仅VCC部分电路工作,芯片温度50℃左右。感觉空载温升这么大,是否正常?In order to reduce the heating condition of the chip, the VIN pin is connected to the external auxiliary power supply through 10Ω. When the external auxiliary power supply is adjusted to 7.5V, R2, R3, R4 and R5 are disconnected. When connected to DC input, the voltage of the VCC pin is only 6 V. After adjusting the auxiliary power supply to about 9V, the voltage of the VCC pin reaches 7.35V. At this time, the power supply does not work. Only part of the VCC circuit works, and the chip temperature is about 50℃ centigrade. Is it normal to feel no-load temperature rising so much?

  1. 按照规格书中推荐的接法,空载时芯片温度一值上升,能到90℃以上,温升这么严重,正常吗?According to the recommended connection method in the specification, when no load, the chip temperature rises to above 90 C. Is it normal that the temperature rises so severely?
  2. 按照规格书中推荐的外部电源接法,将辅助电源接至BIAS管脚后,如果VIN 不连接则VCC没有输出,这是怎么回事?如果连接至BIAS,则芯片温度很高(>90℃),明显没有通过BIAS供电,还是通过VIN供电。According to the external power connection recommended in the specification, the auxiliary power supply is connected to the BIAS pin, and if the VIN is disconnected, the VCC does not output. What happens? If connected to the BIAS, the chip temperature is very high (>90 C), obviously not through the BIAS power supply, or through the VIN power supply.
  3. 按照DEMO板LM5176EVM-HP的参数焊接PCB,按照12V4A测试,效率不高,温度较高,输入电压升高时Q2温度上升很快。目前状态是:电源无法正常工作,效率极低50%左右,带0.5A负载,HDRV1驱动的MOS管温度很快能升到100℃以上,测试BOOT1和BOOT2的电压都只有3V多。According to the parameters of DEMO LM5176EVM-HP, PCB is welded. According to the 12V4A test, the efficiency is not high and the temperature is high. When the input voltage rises, the Q2 temperature rises rapidly. Current status is: the power supply can not work properly, the efficiency is very low about 50%, with 0.5A load, the temperature of HDRV1-driven MOS tube can quickly rise to more than 100 C, the test voltage of BOOT1 and BOOT2 are only more than 3V.