ZHCSMX3C December 2020 – February 2023 LM5149-Q1
PRODUCTION DATA
#SNVSB29620 shows the schematic diagram of a single-output synchronous buck regulator with an output voltage of 5 V and a rated load current of 8 A. In this example, the target half-load and full-load efficiencies are 93.5% and 92.5%, respectively, based on a nominal input voltage of 12 V that ranges from 5.5 V to 36 V. The switching frequency is set at 2.1 MHz by resistor RRT. The 5-V output is connected to VCCX to reduce IC bias power dissipation and improve efficiency. An output voltage of 3.3 V is also feasible simply by connecting FB to VDDA (tie VCCX to GND in this case).
This and subsequent design examples are provided herein to showcase the LM5149-Q1 controller in several different applications. Depending on the source impedance of the input supply bus, an electrolytic capacitor can be required at the input to ensure stability, particularly at low input voltage and high output current operating conditions. See Power Supply Recommendations for more detail.