STMicroelectronics LDL40PURY

Overview

LDL40PURY from STMicroelectronics is an AEC-Q100 Grade 1 qualified adjustable low-dropout linear voltage regulator designed for direct connection to automotive battery rails (up to 40 V input), delivering up to 200 mA with 700 mV typical dropout at full load, ±2.5% output voltage accuracy over -40 °C to 150 °C junction temperature, and ultra-low 2 µA quiescent current at no load - enabling long-term operation in always-on vehicle subsystems such as ADAS sensors and infotainment power domains.

For engineers reviewing the LDL40PURY datasheet, LDL40PURY pinout, LDL40PURY application, or LDL40PURY equivalent, key selection considerations include its DFN6 (2 × 2) wettable flanks package, ADJ pin configuration supporting 1.2–12 V output, Power Good monitoring capability, logic-controlled shutdown (<0.3 µA standby), and integrated thermal/current protection for harsh automotive environments.

Technical Context

The LDL40PURY employs a P-channel MOSFET pass element enabling low dropout and high PSRR (70 dB for fixed versions, 65 dB for adjustable), with internal bandgap reference and error amplifier providing stable regulation across wide temperature and load ranges. Its enable-controlled startup includes 800 µs turn-on time and precise Power Good thresholding (93–98% of VOUT).

Thermal shutdown activates at 170 °C with 20 °C hysteresis, and output active discharge uses a 70 Ω internal MOSFET. The device supports remote sensing via ADJ/VSENSE pin and requires only ceramic input/output capacitors (≥1 µF each) for stability - eliminating need for external compensation.

Key Specifications

Pinout & Package

LDL40PURY is housed in a DFN6 (2 mm × 2 mm) wettable flanks package with exposed thermal pad, optimized for automated optical inspection (AOI) and high-density PCB layouts in automotive ECUs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable LDO regulator applications.

Compared with TLD1117V33 and NCP1117DTAR, LDL40PURY uniquely combines AEC-Q100 Grade 1 qualification, adjustable output, ultra-low IQ, and integrated PG/discharge in a wettable-flank DFN6 - making it the sole choice for compact, battery-sensitive automotive subsystems requiring functional safety-aware power management.

Availability

LDL40PURY is available at Aetrix Electronics and suitable for EV powertrain control units, ADAS camera modules, and infotainment instrument clusters requiring stable component supply across extended temperature and automotive lifecycle demands.

Supply support for LDL40PURY includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader specializing in automotive, industrial, and power management solutions, with broad portfolio coverage from MCUs to analog ICs and discrete devices.

LDL40PURY belongs to ST's automotive-grade LDO family engineered specifically for battery-connected applications demanding ultra-low quiescent current, high input voltage tolerance, and AEC-Q100 reliability - targeting next-generation E/E architectures in electrified vehicles.

FAQ

What is the minimum input voltage required for LDL40PURY to regulate?

The LDL40PURY begins regulation when VIN reaches VOUT(NOM) + VDROP, with typical dropout of 700 mV at 200 mA. For example, with 3.3 V output, minimum VIN is ~4.0 V. The device can start up with as low as 3.3 V input, but regulation is only guaranteed above the dropout threshold. Startup behavior is validated across -40 °C to 150 °C junction temperature.

How does the ADJ pin function in LDL40PURY?

The ADJ pin serves as both output voltage adjust input (for adjustable versions) and remote sense node (for fixed versions). When configured as adjustable, it connects to a resistor divider between VOUT and GND to set output from 1.2 V to 12 V using VREF = 1.2 V. ADJ pin operating current is 0.1–0.5 µA, minimizing divider resistor power loss.

Can LDL40PURY be used without the Power Good (PG) pin?

Yes - the PG pin is optional and functions as an open-drain output. It remains high-impedance when enabled and VOUT is within specification, or when EN = low. If unused, it may be left floating or tied to VOUT via pull-up; no external pull-up is required for basic regulation, though system-level monitoring benefits from its fault-signaling capability.

What thermal derating applies to LDL40PURY in a standard FR4 PCB layout?

With a 1 sq-in copper pad (1 oz Cu), RthJA is 62 °C/W. At 25 °C ambient, maximum continuous power dissipation before reaching 150 °C junction limit is ~2.0 W. Derating follows linear curve: power must reduce by ~16 mW/°C above 25 °C ambient. Full derating data is provided in Figure 6 of DS14146 Rev 3.