Dear,
I have designed a board with BQ25895 to recharge a LiPo battery with an external adapter (no USB device will be used). So I left the pins D+ and D- floating with a option to connect them by a 0R resistor. I also left floating pins DSEL, OTG, STAT and INT (since no interrupt is requerid). All the connections was done follwing the webench schematics.
My requeriments are: recharger the 1cell LiPo battery (4.2V) with 2A, using a external adapter 5V 2A.
The config registers are below:
REG00 = 0xE6 // Enabling HIZ, ILIM, and 2A of input current limit.
REG01 = 0x06 // Default
REG02 = 0xE0 // Enabling ADC, at 1 sec continuous, ICO Dis, ADE Dis
REG03 = 0x1A // Default? On the register bits the default bit 5 is 0 and on the table, the default bit 5 is 1. I don't know wich is the default, but I'm programming as 1Ah by the way.
REG04 = 0x20 // Default (Fast Charge Current Limit 2048mA)
REG05 = 0x13 // Default
REG06 = 0x5E // Default
REG07 = 0xCD // Default except STAT Dis
REG08 = 0x03 // Default
REG09 = 0x44 // Default
REG0A = 0x93 // Default
REG0D = 0x12 // Default
Could you please, help me to answer the following questions:
1) The pins that I left floating are ok or should be tied to any reference?
2) When the REG00 is programmed with current limit up to 800mA, sometimes the recharger starts. But when programmed for 2A, it never starts. Why?
3) When the External Power Supply is plugged in, but, I don't know why, the battery is not charging (I can't see any current been drawing from the power supply), if I remove the external power supply, the Vsys also goes off. Why?
4) I tried to program the REG00 with only 300mA. The board start to drain around 290mA at 5V Power Supply (that was I expect). Then I increased the current on REG00 on steps of 100mA. The Power Supply current was incresed too... When reached more than 800mA, the system shut down. Why?
I'm looking forward your feedback...
Thanks in advance..
Ivan
