2-cell Li-Ion linear charger in TSSOP-8
The Texas Instruments BQ2057TTSG4 is a linear charge-management IC designed specifically for 2-series Lithium Ion or Lithium Polymer battery packs, with a regulated output of 8.2V. It operates from a supply up to 15V and integrates constant-current/constant-voltage (CC/CV) charging with programmable current via an external sense resistor.
The 8.2V battery pack voltage is the full-charge target for a 2-series Li-Ion stack (4.2V per cell). This part will not terminate correctly on a single-cell (4.2V) or 3-cell (12.6V) pack — the voltage regulation loop is fixed. The programmable charge current allows the designer to set the CC rate with a single resistor, matching the cell capacity and thermal budget of the TSSOP-8 package.
No last-time-buy window is in effect. For volume production, confirm whether your assembler prefers Tape & Reel — the base product number BQ2057 covers multiple reel options.