LDQ40PU50RY

Overview

The STMicroelectronics LDQ40PU50RY is a fixed-output low-dropout linear regulator providing a nominal 5.0 V output with a guaranteed maximum load current of 250 mA. It operates within an input voltage range of 3.3 V to 40 V and features a typical dropout voltage of 500 mV at full load. The device achieves high accuracy with an output tolerance of ±0.5% at 25 °C and ±1.5% over the extended temperature range. Designed for automotive environments, it holds AEC-Q100 Grade 1 qualification and supports junction temperatures from -40 °C to +150 °C. Quiescent current is typically 2 μA at no load, rising to 200 μA at 250 mA load.

Feature Summary

• AEC-Q100 Grade 1 qualified for automotive reliability
• Logic-controlled electronic shutdown reduces standby consumption below 0.3 μA
• Integrated Power Good open-drain output monitors regulation status
• Output active discharge function rapidly discharges external capacitance

Applications

• EV powertrain systems
• Always-on battery connected applications
• Infotainment and instrument clusters
• Advanced Driver Assistance Systems (ADAS)

Procurement Notes

Verify the specific suffix 'RY' indicates the DFN6 2x2 wettable flanks package required for automotive-grade assembly standards. Confirm that the ordering code matches the fixed 5.0 V output requirement. Ensure procurement channels provide traceability documentation consistent with AEC-Q100 Grade 1 specifications. Check for updated revision history in the datasheet to confirm component maturity status before finalizing design-in.

Selection Notes

Select this component when a stable 5 V rail is required for sensitive automotive logic or sensors. The wide input range accommodates direct connection to vehicle batteries or pre-regulated sources. The compact DFN6 footprint suits space-constrained PCB layouts. Consider the thermal resistance of the wettable flank package for heat dissipation calculations under heavy loads. Verify that the external ceramic capacitor ESR falls within the stability region defined in the application guidelines.

Part Context

The LDQ40 series comprises high-accuracy LDO regulators designed for automotive and industrial markets. This specific part belongs to the fixed-output variants, offering precise voltage regulation without external feedback resistors. The family includes adjustable versions and different package options like SOT23-5L, but the PU50RY variant specifically targets the 5 V fixed application in the automotive-qualified DFN6 format.

Replacement Considerations

LDQ40PU50R serves as the industrial-grade alternative using the standard DFN6 2x2 package without wettable flanks.