Multi-chemistry charger with I²C programmability
The Texas Instruments BQ24721RHBTG4 is a multi-chemistry battery charger IC designed for 3 to 4 series cells, with a maximum battery pack voltage of 19.2 V. The I²C interface lets the host system program charge current and set protection thresholds, replacing resistor-strapped configuration on simpler chargers. Overcurrent fault protection is integrated, reducing external supervisory circuitry.
Maximum supply voltage is 24 V, which covers the input from a typical 19 V notebook adapter with margin.
Package and footprint
The pad is the primary thermal path — without it, the die temperature rises above the safe operating limit at full charge current. Surface-mount assembly with standard lead-free reflow profiles; the exposed pad demands a solder-paste stencil opening that covers 50–70 % of the pad area for void-free attach.
The BQ24721RHBTG4 carries an obsolete lifecycle status. No factory orders are accepted; new- and surplus-stock is the only supply path.