SBVS426B December 2022 – October 2024 TPS25772-Q1
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
VIN Supply
The voltage VIN at the input supply pin IN, measured with respect to AGND, must meet the following requirements:
The buck-boost switching converter is capable of delivering its full rated output power of 65 W over an input supply range 6.8 V < VIN < 18 V . The input voltage can dip down to the UVLO threshold providing that the output power level is appropriately derated.
VIN Overvoltage Protection Circuitry
The TPS25772-Q1 contains circuitry that protects the power train against load dump and double battery conditions. When VIN exceeds approximately 19 V, a comparator determines that an input overvoltage condition has occurred. This comparator sends a signal that shuts the switching converter down. Transistors M1, M2, and M3 in Buck-Boost Internal Power FETs are turned off, and transistor M4 is turned on. However, current is still flowing through the inductor. Two cases may exist: the current may flow forward (from SW1 to SW2) or in reverse (from SW2 to SW1). Reverse current flow will forward-bias the body diode of M1. The voltage across the inductor then equals the sum of the forward voltage of this diode plus the input voltage, which is sufficient to cause the inductor voltage to rapidly ramp down to zero. Forward current flow will forward-bias the body diode of M2. After the inductor current is released, a small linear regulator biases SW1 to approximately 15 V. When the overvoltage condition is removed, the switching regulator may resume operation.