SLUS618I August 2004 – December 2014
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
請參考 PDF 數據表獲取器件具體的封裝圖。
The power select pin, PSEL, defines which input source is to be used first (primary source – AC or USB). If the primary source is not available, then the IC automatically switches over to the other secondary source if available or the battery as the last option. If the PSEL is set low, the USB input is selected first and if not available, the AC line is selected (if available) but programmed to a USB input limiting rate (100 mA/500 mA max). This feature allows the use of one input connector, where the host programs the PSEL pin according to what source is connected (AC adaptor or USB port).
The bq24038 replaces USBPG with pin VBSEL, to enable user selection of the charge voltage. In addition, pin ACPG was modified to PG. PG is active low when either ac power or USB power is detected.
The ISET1 pin programs the battery's fast charge constant current level with a resistor. During normal AC operation, the input supply provides power to both the OUT (System) and BAT pins. For peak or excessive loads (typically when operating from the USB power, PSEL = Low) that would cause the input source to enter current limit (or Q3 - USB FET limiting current) and its source and system voltage (OUT pin) to drop, the dynamic power-path management (DPPM) feature reduces the charging current attempting to prevent any further drop in system voltage. This feature allows the selection of a lower current rated adaptor based on the average load (ISYS-AVG + IBAT-PGM ) rather than a high peak transient load.