Hi,
I would like to ask a question on Dynamic Power Path Management.
There is a division on TI's Battery Charger Selection tool that some chargers have "Dynamic Power Path Management" and some not. For those having such feature, there datasheet describes the charger as being capable of "charge the battery and supply the system simultaneously".
I read from http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries that battery should not be used and charged at the same time:
Some portable devices sit in a charge cradle in the on position. The current drawn through the device is called the parasitic load and can distort the charge cycle. Battery manufacturers advise against parasitic load because it induces mini-cycles. The battery is continuously being discharged to 4.20V/cell and then charged by the device. The stress level on the battery is especially high because the cycles occur at the 4.20V/cell threshold.
A portable device must be turned off during charge. This allows the battery to reach the set threshold voltage unhindered, and enables terminating charge on low current. A parasitic load confuses the charger by depressing the battery voltage and preventing the current in the saturation stage to drop low. A battery may be fully charged, but the prevailing conditions prompt a continued charge. This causes undue battery stress and compromises safety.
So is this the motivation for "Dynamic Power Path Management"? If without "Dynamic Power Path Management", the battery might be charged while still supplying current to the system; but with "Dynamic Power Path Management", when the battery is being charged and the system is still on, the system could be supplied by the current routed directly from the AC adapter or USB, thus will not cause any parasitic load and/or mini-cycle.
Is this the intention of "Dynamic Power Path Management" design?
Zheng
