JAJSV63A August 2024 – August 2024 LM5137-Q1
ADVANCE INFORMATION
The LM5137-Q1 is a dual-channel switching DC/DC controller that features all of the functions necessary to implement a high-efficiency synchronous buck regulator. The device is offered from a controller family with three options for functional safety applications: Capable, ASIL B, or ASIL D, with the latter two options designated by an "F" suffix in the part number.
Operating over a wide input voltage range from 4V to 80V, the LM5137-Q1 is configured to provide a fixed 3.3V, 5V or 12V output, or an adjustable output between 0.8V and 60V. This easy-to-use controller integrates high-side and low-side MOSFET gate drivers, each capable of sourcing 2A and sinking 3A peak current. Adaptive dead-time control is designed to minimize body diode conduction during switching transitions.
Peak current-mode control using a shunt resistor or inductor DCR current sensing provides inherent line feed forward, cycle-by-cycle peak current limiting, and easy loop compensation. Current-mode control also supports a wide duty cycle range for high input voltage and low dropout applications as well as when a high voltage conversion ratio (for example, 10-to-1) is required. The oscillator frequency is user-programmable between 100kHz to 2.2MHz, and the frequency can be synchronized as high as 2.5MHz by applying an external clock to PFM/SYNC. A user-selectable PFM mode feature enables discontinuous conduction mode (DCM) operation to further improve efficiency and reduce power dissipation during light-load conditions.
The LM5137-Q1 incorporates features to simplify the compliance with automotive EMI requirements (CISPR 25). An optional spread spectrum frequency modulation (DRSS) technique reduces the peak EMI signature, while the adaptive gate drivers minimize high-frequency emissions. Finally, 180° out-of-phase interleaved operation of the two controller channels reduces input filtering and capacitor requirements.
The LM5137-Q1 is provided in a 36-pin VQFN package with a wettable flank pinout and an exposed pad to aid in thermal dissipation.