SLVSH95A July 2024 – September 2025 TPS546C25
PRODUCTION DATA
In a stacked 2-phase configuration of the TPS546C25, understanding that only the primary device directly controls the output voltage is crucial. Secondary devices are configured to match the primary device voltage setting to make sure of proper current sharing and operation. For the primary device using an internal feedback divider, connect a resistor from VSEL/FB to AGND to set the output voltage. If using an external feedback divider, VSEL/FB must be connected to the midpoint of an external resistor divider between VOUT and GOSNS. On the secondary device, the VSEL/FB pin must be connected to a resistor to AGND to select the appropriate VOUT_SCALE_LOOP value for the output voltage. If the primary device uses an internal divider, use the same VSEL resistor value as the primary. For primary devices using an external divider, select the VSEL resistor with the lowest VOUT_MAX greater than the maximum expected output voltage.
In terms of grounding, each TPS546C25 device must have a separate analog ground island. These islands must be connected to the respective PGND with a topside metal feature between the AGND pin and the PGND pad, rather than being connected externally with a resistor. For voltage sensing, both primary and secondary VOSNS must connect at the same point on the output voltage node, ensuring ripple contributions from both phases. The same principle applies to FB connections in external divider configurations. By following these guidelines, engineers can make sure of proper operation and optimal performance of the TPS546C25 in a 2-phase configuration.