LM5175PWPR

The switching frequency of the LM5175 controller can be programmed between 100kHz and 600kHz using a resistor connected from the RT/SYNC pin to AGND. The RT resistor is related to the nominal switching frequency (Fsw) according to a specific equation. A 1% standard resistor of 84.5 kΩ is selected for a programmed switching frequency of 300kHz .

The LM5175 synchronous 4-switch buck-boost controller supports a wide input voltage range of 3.5V to 42V, with a maximum of 60V.

The LM5175 controller features current-mode control in both buck and boost modes, allowing for superior load and line regulation. It has a programmable switching frequency that can be synchronized to an external clock signal. Additionally, the device includes a programmable soft-start function and various protection features such as cycle-by-cycle current limiting, input undervoltage lockout (UVLO), output overvoltage protection (OVP), and thermal shutdown. The LM5175 also offers selectable Continuous Conduction Mode (CCM) or Discontinuous Conduction Mode (DCM) operation, optional average input or output current limiting, spread spectrum for reducing peak EMI, and hiccup mode protection in sustained overload conditions. The LM5175 comes in different package options, such as HTSSOP-28 with a body size of 9.7mm x 4.4mm and QFN-28 with a body size of 4.0mm x 5.0mm. In terms of applications, the LM5175 is a four-switch buck-boost controller that can be used to design buck-boost converters. It offers a quick-start tool on the product webpage for designing converters and Webench® software for creating complete designs, estimating efficiency, solution size, and cost. The document also provides a detailed step-by-step design procedure for a typical application circuit using the LM5175.