STMicroelectronics LDH40 and LDQ40 voltage regulators

The STMicroelectronics LDH40 and LDQ40 voltage regulators are suitable for automotive and industrial applications. The voltage regulators start up from an input as low as 3.3 V, operate with up to 40 V applied, and have low quiescent current. The LDH40 delivers up to 200 mA and is available in one version only, with an adjustable output voltage from 1.2 to 22 V. The 250 mA LDQ40 is available with a 1.2–12 V adjustable output and a choice of 1.8 V, 2.5 V, 3.3 V, and 5.0 V fixed output voltages.

These low-dropout (LDO) regulators are designed to facilitate efficient power conversion for energy-conscious applications. The quiescent current of 2 µA at zero load and 300 nA logic-controlled shutdown mode help preserve battery energy in always-on standby systems. The devices are stabilised with a small ceramic capacitor on the output.

The automotive devices are AEC-Q100 qualified and packaged as 2 x 2 mm DFN6L devices with wettable flanks that ease PCB design and facilitate automated optical inspection. Their wide input-voltage range allows connection to a vehicle 12 V bus that can reach up to 40 V transient, to power infotainment systems, instrument clusters and advanced driver-assistance systems (ADAS). With their low quiescent and standby current, they are also suited for use in electric vehicles.

All the LDOs have system protection and management features including internal current limiting, thermal protection, soft-start and output active discharge. There is an enable pin for shutdown control and a power-good pin for diagnostic monitoring. The LDQ40 devices also have short-circuit protection.

The LDH40 automotive-grade regulator is in production now in a DFN6L wettable flank package. The adjustable-output LDQ40 regulators, in industrial and automotive grade, are in production as well, in the standard DFN6L package and wettable-flank package for automotive applications. Free samples for both LDH40 and LDQ40 are available at the ST eStore.