急！急！急！BQ24195 充放电切换（charge boost两种模式切换）疑问

1. One thing to notice is that when you disconnect your input to allow OTG pin to go high, there will be a transition delay of ~220ms from when the device transitions from buck mode to boost mode, this is to ensure proper and safe transition. During this transition, the PMID voltage will go from ~VBAT at PMID to the OTG output once OTG starts. Majority of our devices that support OTG have this delay, meaning if your application requires an uninterrupted 5V source at PMID, you would need an additional power stage that can provide this rail. In this case, perhaps a buck-boost stage at SYS is more appropriate.
2.You can tie /CE to ground if you don't need to control it with the host. You can always disable/enable charger as well over I2C using the host using REG01[5:4].
One thing, in order for OTG to start, there are several conditions that need to be met:
1. BAT above BATLOWV threshold (VBATLOWV set by REG04[1])
2. VBUS less than BAT+VSLEEP (in sleep mode)
3. Boost mode operation is enabled (OTG pin HIGH and REG01[5:4] = 10)
4. After 220-ms delay from boost mode enable

The gating action to enable OTG after the input is removed will be item#2. Your host needs to modify REG01[5:4] to configure the device to OTG, hence why the device won't transition to OTG automatically upon input removal.