The DV2003S2 Development System provides a development environment for the bq2003 Fast-Charge IC. The DV2003S2 incorporates a bq2003 and an n-FET buck-type switch-mode regulator to provide fast charge control for 2 to 16 NiCd or NiMH cells. The primary difference between the DV2003S2 and the DV2003S1 is in the switching FET Q1. The DV2003S1 uses a P-FET for battery charge currents of 3.0A or less, whereas the DV2003S2 uses an N-FET to support charge currents up to 6.0A.
Review the bq2003 data sheet and the application note,"Using the bq2003 to Control Fast Charge," before using the DV2003S2
board. Also review the application note, "Step-Down Switching Current Regulation Using the bq2003," for information concerning trade-offs between using P-FET and N-FET transistors for Q1.
The fast charge is terminated by any of the following: DT/Dt, -DV, maximum temperature, maximum time, maximum voltage, or an external inhibit command. Jumper settings select the -DV enabled state, and the hold-off, top-off, and maximum time limits.
The user provides a power supply and batteries. The user configures the DV2003S2 for the number of cells,-DV
charge termination, and maximum charge time (with or without top-off), and commands the discharge-before-charge option with the push-button switch S1.