The LMR436x0-Q1 is a wide input, low-quiescent current, high-performance regulator that can operate over a wide range of duty ratio and switching frequencies, including sub-AM band at 400kHz and above AM band at 2.2MHz. During wide input transients, if the minimum on time or the minimum off time cannot support the desired duty ratio at the higher switching frequency settings, the switching frequency is reduced automatically, allowing the LMR436x0-Q1 to maintain the output voltage regulation. With an internally compensated design optimized for minimal output capacitors, the system design process with the LMR436x0-Q1 is simplified significantly compared to other buck regulators available in the market.

The LMR436x0-Q1 is designed to minimize external component cost and design size while operating in all demanding automotive environments. The LMR436x0-Q1 family includes variants that can be set up to operate over a wide switching frequency range, from 200kHz to 2.2MHz, with the correct resistor selection from the RT pin to ground. To further reduce system cost, the PGOOD output feature with built-in delayed release allows the elimination of the reset supervisor in many applications.

The LMR436x0-Q1 family is designed to reduce EMI/EMC emissions. The design includes a dual random spread spectrum switching frequency dithering scheme, has no bond-wire flip-chip on the lead (HotRod) package, and is available with the MODE/SYNC feature (select variants), allowing synchronization to an external clock, when available. Together, these features eliminate the need for any common-mode choke or shielding or any elaborate input filter design scheme, greatly reducing the complexity and cost of the EMI/EMC mitigation measures.

The LMR436x0-Q1 comes in an ultra-small 2mm × 2mm QFN package with wettable flanks, allowing for quick optical inspection along with specially designed corner anchor pins for reliable board level solder connections.