> > Trying to understand this... It seems you are saying the default state of > the TPS65215C is to have the AC pin internally connected to the USB pin. > But the datasheet says: > ----- > AC input is prioritized over USB input, i.e. if both inputs are valid, > current is pulled from the AC input and not USB. If both, AC and USB > supplies are available, the power-path switches to USB input if VAC drops > below 4.1 V (fixed threshold). > > Note that the rise time of VAC and VUSB must be less than 50 ms for the > detection circuits to operate properly. If the rise time is longer than 50 > ms, the IC may fail to power up. > > The linear charger periodically applies a 10-mA current source to the BAT > pin to check for the presence of a battery. This will cause the BAT > terminal to float up to > 3 V which may interfere with AC removal detection > and the ability to switch from AC to USB input. For this reason, it is not > recommended to use both AC and USB inputs when the battery is absent. > ----- > > So there is the official word on all the power supply rise-time issues > people report! > > ----- > AC and USB Input Discharge > AC and USB inputs have 90-µA internal current sinks which are used to > discharge the input pins to avoid false detection of an input source. The > AC sink is enabled when USB is a valid supply and VAC is below the > detection threshold. Likewise, the USB sink is enabled when AC is a valid > supply and VUSB is below the detection limit. > > Both current sinks can be forced OFF by setting the [ACSINK, USBSINK] bits > to 11b. Both bits are located in register 0x01 (PPATH). > ----- > > There is an even more important reason for never having AC and USB > connected simultaneously. > > Sure sounds to me like the TPS65215C never turns on both FETs at the same > time. > > > But as I asked before, the reality is best known from the RMA stream - do > people actually fry their TPS2051 switches? > > Loren > > > On Wednesday, January 8, 2014 5:33:51 AM UTC-8, Gerald wrote: > The TPS65215C passes what ever voltage is supplied to it out heat pin as > long as it is not over 7.2V, which is mote than 5V. So, while the TPS65217C > can run at 6V, the TPS2051 cannot,. > > Gerald > >
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