3.6V fixed LDO for 24V industrial rails
The ST732M36R is a fixed 3.6V output LDO from STMicroelectronics, rated for 300 mA continuous output with a maximum dropout of 1.2 V at full load. The 28 V input ceiling lets it drop directly from a 24 V industrial bus without a pre-regulator, saving board space and a conversion stage. Quiescent current is 10 µA typical, making this LDO suitable for always-on sensor supplies where standby draw must stay below 20 µA. The supply current max is 200 µA, covering the control and bias overhead.
Dropout and thermal headroom at 300 mA
The 1.2 V max dropout at 300 mA defines the minimum input-to-output differential: feeding 4.8 V in guarantees 3.6 V out at full load. Compare this to the LD39020DTPU33R, a 200 mA LDO with a 3.3 V fixed output and a lower 5.5 V input limit — the ST732M36R handles higher input voltage and delivers 100 mA more current, but the LD39020 includes a soft-start feature and an enable pin for sequenced power-up. At 125°C ambient, the 300 mA load creates a temperature rise inside the SOT-23-5 package — the dropout voltage increases with junction temperature, so budget 1.2 V dropout at 25°C and expect ~1.5 V at 125°C per the typical curve.
Active production, ROHS3, and package options
ROHS3 compliance is confirmed, covering the full bill of materials for EU and global markets. The SC-74A, SOT-753 case code matches the industry-standard SOT-23-5 land pattern — no footprint surprise during layout.