SLUSG51A October 2025 – August 2026 BQ25692-Q1
PRODUCTION DATA
Low ESR ceramic capacitors such as X7R or X5R are preferred for the decoupling capacitors and must be placed close to the converter VIN, SYS or SRN and GND pins. To account for the derating due to temperature and applied voltage of a ceramic capacitor, the voltage rating of the selected ceramic capacitor must be higher than the normal input voltage level. For example, a capacitor with 35V or higher voltage rating is preferred for up to 24V input voltage. Non-ceramic capacitors can be used if the ESR is less than 50mΩ. CVIN_ACP + CVIN_ACP must be at least 10µF after derating with CVIN_ACN < 4 × CVIN_ACP. For 1S-2S applications, CSYS must be at least 15µF. For 3S-7S applications, CSYS must be at least 8µF after derating. CBAT, the bulk capacitance close to SRN and GND pins in parallel with the battery pack, must be at least 5µF after derating. The following sections explain how to size the derated capacitance value for the desired steady state voltage ripple. Voltage ripple is the highest for the input of a buck converter and the output of a boost converter. At the start and release of a load transient step, additional capacitance can be required to reduce voltage dips and overshoot, respectively, for a buck, boost or buck-boost converter output.