TAS5825M: PVDD供电，DVDD悬空会有电压

您好，

     和相关的专家重新确认了一下，他的回复如下，请参考：     

When DVDD is floating while PVDD is powered, voltage might "couple" or "leak" to the DVDD pin from PVDD via parasitic diodes, leakage currents, or protection circuits (like ESD diodes) inside the chip.
The measured 2.68V is likely a "clamped voltage" formed through an internal protection diode (e.g., a clamp diode from PVDD to DVDD) or a parasitic path – a parasitic conduction phenomenon when the chip is not fully powered down.

Never leave DVDD floating! Its level must be actively controlled.

The phenomenon you observed (2.68V at DVDD when PVDD=22V and DVDD is floating) is due to unintended voltage coupling caused by internal parasitic paths or protection diodes in the chip. Strictly speaking, this is not the chip's 'normal operating state' but rather a 'parasitic conduction' phenomenon occurring under non-standard power sequencing.
To ensure system stability and chip safety, we strongly recommend avoiding a floating DVDD in the design. We suggest adding a 100kΩ ~ 1MΩ pull-down resistor to the DVDD pin. 

您好，

     即使增加了100K / 330K下拉电阻，电压“没有变化”。这表明：
1. 下拉电阻不足以“拉低”由内部二极管钳位建立的电压（当内部二极管导通时，它表现为低阻抗路径）。
2. 或者，芯片的内部寄生电容/路径在上电过程中会产生瞬态电压下降，而慢速下拉电阻无法及时响应。

这种“下降”不是稳态电压，而是在上电瞬间的瞬态现象。即使稳态电压为2.68V，由于电容放电或路径切换，瞬时电压仍可能下降。