BQ76952: 芯片进入shutdown状态，无法恢复

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测试过后发现REG18存在1.8V电压，说明芯片处于是打开的状态，但功耗是只有18uA，且MCU始终无法与BQ通信，试过在LD两端给一个电压，依旧无法恢复到正常状态，请问RST_SHUTDOWN拉高一下或者是否可解决这种问题？还有是ALERT引脚在产生CUV报警之后只有从拉高的状态变为拉低的状态后一直保持拉低的状态，我们需要是在报警之后拉低之后还是报警清除后还是可以拉高，在测试过程中发现，清除报警后仍然保持低，且通过MCU手动恢复，仍无法使ALERT在拉低后再拉高，ALERT pinconfig寄存器配置为0x82同时关闭了protection的相关寄存器。如下图所示。

已看到工程师的答复，现将原理图上传

SHUTDOWN 如何恢复，在LD两端给到一个电压，仍然无法启动，将RST_SHUT引脚拉高一次，持续时间不超过1s发现BQ仍没有工作在正常状态。

ALERT PIN 在ALERT功能是否可以配置为开漏模式

Luis H.S说：

You mentioned that they measured 1.8-V in REG18, while power consumption remains low. It is possible that the device is stuck in "soft shutdown". Which can occur if TS2 is pulled low or if there's a voltage on the LD pin. Can they explain in detail what happens when they're having SHUTDOWN issues? If they reset the device does it get fixed? 

BQ的TS2和LD电压在上电后都为0,同时通过MCU引脚在RST_SHUT引脚拉高，拉高后确实功耗变高了，但是BQ仍然无法通信。REG1确实有1.8V的电压。

Luis H.S说：

Are they using 100-Ohm for their sense resistors? This seems very high for a sense resistor. What discharge/charge currents do they expect? I also am concerned of the diodes used there, the diodes have a non-linear turn-on and can shift with temperature, so I am concerned that these would affect SRN/SRP measurements. The abs. max of the SRN/SRP pins are a minimum of -0.3-V to a maximum of 2.1-V. So you probably only need to worry about exceeding the absolute min.

灵敏电阻是0.25毫欧，不是100欧，图中的R30和R178并联

Luis H.S说：

Ideally they should reference BAT- to Vss. Since they are not directly connecting to Vss, they should add a Schottky and Zener diodes on VC0 to keep it within the ABS maximum values

请问下如果BAT-没有连接到Vss，需要增加肖特基二极管和齐纳二极管是为什么，请问这两个二极管的耐压值应该选择何种型号。. 

 Luis H.S未回答关于ALERT的问题。麻烦追问下这个引脚ALERT功能下是否可配置为开漏模式。

Luis H.S说
Can they communicate if they use an EVM? If REG1.8 is on, the device should be awake. RST_SHUT should not be pulled high unless they want the part to go into SHUTDOWN or RESET.

Luis 的意思是否是指使用评估板是否可通信是吗？我们使用的硬件是按照手册提供的电路图进行涉及，部分管脚有作修改，参照之前提供的原理图。REG18是存在的，REG1没有，保持RST高电平功耗有提升但是通信时关闭状态。在之前有提到过LD两端的电压和TS2两端的电压都为0，这是否会影响芯片进入到SOFT SHUTDOWN.

Luis H.S说

This can be configured in the Alert Pin Configurations. See Section 13.3.2.11 Settings:Configuration:ALERT Pin Config of the TRM.

按照TRM中的配置在电池欠压的状态确实有产生一个脉冲信号，我们需要的功能是当外部有一个微弱的电流是，alert引脚是否也可产生一个interrupt信号给主机进程。如果想实现当外部有微弱电流时，ALERT可产生一个Interrupt信号给主机进程，请问如何实现

Luis H.S说

Could they specify what you mean by weak external current? If using it as the ALERT configuration when there's a fault, there's no way to do this. Maybe if they set up this pin as a GPIO. They'll have to figure out the code to do this

我们需要当电池进入充电状态下时，ALERT引脚产生一个脉冲，这个脉冲我们主要是用于可以唤醒MCU的，按照Luis H.S的建议，是否是将该引脚配置位GPIO的输出模式，然后当充电时，该引脚拉低再拉高