JAJSVI1 October 2024 TPS25763-Q1
PRODUCTION DATA
The buck and boost peak current limits are adjustable by firmware using the application configuration GUI. Refer to the BUCK-BOOST PEAK CURRENT LIMITS in Buck-Boost Regulator of the Electrical Characteristics tables for selectable values.
In most applications it is desirable to limit input current to the automotive USB module to protect module components, connectors and wiring from over-current conditions. The worst case input current condition occurs when VIN is minimum and VCSN/BUS is maximum (21 V) while supplying maximum 3.25 A output current. When VIN < VBUS, the internal DC/DC converter is operating in boost mode. Refer to the Buck Calculation Results (L=4.7 uH). I BUS = 3 A tables in the Inductor Currents section to estimate the peak current versus recommended inductor value for the application.
The buck peak current limit setting selection can be just lower than the boost peak current limit. Set as close to the boost peak current limit as selections allow to prevent the possibility of limit cycling between the two peak current limits under extreme transients. IPEAK(BUCK) ≅ IPEAK(BOOST).
When selecting an inductor, it is important to select one with an appropriate saturation current rating, IL(SAT). The inductor IL(SAT) rating must be larger than the maximum (MAX) IPEAK(BOOST) limit from the Electrical Characteristics tables to avoid excessive current flow in the TPS25763-Q1 or the inductor.