1.4 A buck regulator with wide input range
The LT1936EMS8E#PBF is a step-down (buck) switching regulator delivering up to 1.4 A from a 3.6 V to 36 V input rail. Its adjustable output is set via external resistors from a 1.2 V reference up to 33.12 V.
500 kHz switching — inductor size vs efficiency
The 500 kHz switching frequency is a practical middle ground: it allows the use of small, low-profile inductors (typically 10 µH to 47 µH range) while keeping switching losses moderate. At this frequency, the regulator can maintain good efficiency across a 3.6 V to 36 V input range without resorting to external compensation. The non-synchronous topology means an external Schottky catch diode is required — factor that into the BOM and board area.
8-MSOP-EP: thermal management at 1.4 A
The 8-MSOP package with exposed pad (MSOP-EP) is the key to getting the full 1.4 A output in a compact footprint. The package is rated for surface-mount assembly and is supplied in Tube (the #PBF suffix indicates ROHS3 compliance).
The 36 V input maximum provides headroom for 24 V systems with transients, but for automotive load-dump events above 40 V, external clamping is still needed.