SNVA941A June 2020 ā November 2022 LM5156 , LM5156-Q1 , LM51561 , LM51561-Q1 , LM51561H , LM51561H-Q1 , LM5156H , LM5156H-Q1
This design guide follows typical design procedures and calculations to implement a non-synchronous boost controller operating in continuos conduction mode (CCM) at full load. The design example uses an unregulated 12-V rail (9 Vā18 V nominal) (2.5 V to 42 V transients) to produce a regulated 12 V of up to 3-A load current. A switching frequency of 440 kHz is selected to avoid interference in the AM band (530 kHz to 1.8 MHz). The minimum supply voltage is selected to be 2.5 V, which is similar to many automotive applications that are required to operate during stop-start conditions and cold cranking conditions. This design is intended to operate continuously at an operating voltage of 4 V but support supply transients as low as 2.5 V. Section 3 details the component selection based on the general design parameters shown in Table 2-1.