STMicroelectronics LD49100PU10RY

Overview

LD49100PU10RY from STMicroelectronics is an AEC-Q100 Grade 1 qualified ultra-low-dropout linear regulator delivering 1 A output current with 200 mV typical dropout at full load, 30 µVRMS output noise (no bypass capacitor required), and ±2.0% output voltage tolerance at 25 °C. It operates from 1.5 V to 5.5 V input and supports fixed 1.0 V output in a DFN6 (3×3 mm) wettable flanks package - designed for automotive infotainment, ADAS, and telematics power rails.

For engineers reviewing the LD49100PU10RY datasheet, LD49100PU10RY pinout, LD49100PU10RY application, or LD49100PU10RY equivalent, key selection criteria include its 1 µA max shutdown current, Power Good open-drain flag, 1 ms internal soft-start, ceramic-capacitor stability (C_OUT = 1 µF), and thermal/short-circuit protection - all validated across −40 °C to +125 °C junction temperature.

Technical Context

The LD49100PU10RY implements a precision bandgap-referenced op-amp control loop with internal current limiting and thermal shutdown at 160 °C (20 °C hysteresis). Its Power Good circuit monitors actual output voltage (not nominal), asserting high-impedance above 93% V_OUT and sinking up to 6 mA when below 91% V_OUT.

Enable logic accepts TTL-compatible thresholds (V_EN(H) ≥ 0.9 V, V_EN(L) ≤ 0.4 V); no internal pull-up requires external biasing. The fixed 1.0 V version uses Pin 5 as VSENSE - must be tied to VOUT or remote load for accuracy - and features 70 dB PSRR at 1 kHz, rolling off above 10 kHz.

Key Specifications

Pinout & Package

LD49100PU10RY uses a 6-pin DFN6 (3×3 mm) package with wettable flanks and exposed thermal pad (connected to GND). The fixed-output variant maps pins as follows:

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout automotive LDO applications.

Compared with TPS7B8133QDCYRQ1 and MC33VR5000A1EP, LD49100PU10RY uniquely combines fixed 1.0 V output, sub-µA shutdown, integrated PG, and lowest noise (30 µV_RMS) - making it optimal for space-constrained, noise-critical automotive logic supplies where pin count and BOM simplicity matter.

Availability

LD49100PU10RY is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and telematics control units requiring stable component supply across extended temperature and long product lifecycles.

Supply support for LD49100PU10RY 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 ICs, with broad portfolio coverage from microcontrollers to analog and power devices.

LD49100PU10RY belongs to ST's automotive-grade LDO family engineered for functional safety-critical power rails - emphasizing ultra-low noise, AEC-Q100 compliance, and robust thermal/short-circuit protection in compact packages.

FAQ

What is the minimum input voltage required for LD49100PU10RY to regulate 1.0 V output?

The LD49100PU10RY requires a minimum input voltage of 1.5 V to maintain regulation. At 1 A load, the 200 mV typical dropout means VIN must be ≥1.2 V theoretically, but the absolute minimum specified is 1.5 V to ensure stability, PSRR performance, and margin across temperature and process variation.

Can LD49100PU10RY operate without an external pull-up resistor on the PG pin?

No - the PG pin is an open-drain output and requires an external pull-up resistor (100 kΩ to 1 MΩ) to VIN or VOUT to generate a valid logic-high signal. Leaving PG floating results in undefined state; if unused, it must remain unconnected per datasheet guidance.

Is the exposed thermal pad electrically isolated or must it be connected to GND?

The exposed pad is internally connected to GND and must be soldered to a PCB GND plane using ≥4 thermal vias. Failure to connect it degrades thermal performance (R_thJA increases from 55 °C/W to >100 °C/W) and risks thermal shutdown under 1 A load.

Does LD49100PU10RY require a bypass capacitor to achieve its 30 µVRMS noise specification?

No - the 30 µV_RMS noise figure is measured with no bypass capacitor, using only the required 1 µF ceramic output capacitor. Adding a bypass cap does not improve noise and may destabilize the control loop if ESR falls outside the 0–150 mΩ range.