The BQ24045DSQT is a single-cell linear charger for Lithium Ion or Polymer packs, with a programmable charge current up to 1A and a battery regulation voltage of 4.35V. That 4.35V ceiling is the high-density cell chemistry sweet spot — standard chargers stop at 4.2V, so if your BOM calls for a 4.35V cell, this part is the fit. It packs over-temperature, over-voltage, and short-circuit fault protection on-chip, which means you don't need a separate supervisor IC for the basic safety envelope.
Charge current and voltage — the two numbers that matter
The 1A max charge current is constant-current programmable via a single resistor. For a 500 mAh cell that means a ~30-minute CC phase; for a 2000 mAh pouch you're looking at over two hours to full. The 4.35V battery pack voltage is the termination ceiling — the charger cuts off at that point, so confirm your cell's absolute max rating is at least 4.35V. If your BOM already uses a 4.2V pack, either of those siblings saves a few cents and widens the temp range on the low end.