STMicroelectronics LD49150PT08R

Overview

LD49150PT08R from STMicroelectronics is an adjustable ultra-low-dropout linear voltage regulator delivering 1.5 A output current with 200 mV dropout at full load, ±1.5% initial output voltage accuracy at 25°C, and dual-supply architecture (VIN: 1.4–5.5 V, VBIAS: 3–6 V) enabling stable 0.8 V core supply for low-power microprocessors in PC add-in cards.

For engineers reviewing the LD49150PT08R datasheet, LD49150PT08R pinout, LD49150PT08R application, or LD49150PT08R equivalent, key selection criteria include bias-supply dependency, ADJ-pin feedback design for sub-1V outputs, fast transient response up to 10 MHz, and PPAK DFN6 (3×3 mm) thermal performance under high-current load regulation.

Technical Context

The LD49150PT08R implements a dual-rail architecture: main input (VIN) powers the output pass device, while separate bias supply (VBIAS) powers control circuitry-enabling ultra-low VIN down to 1.4 V without compromising regulation or transient response. This decoupling ensures stable reference generation and error amplifier operation independent of VIN droop.

Its adjustable configuration uses an external resistor divider on the ADJ pin referenced to 0.8 V internal bandgap (±1.5% tolerance), supporting output voltages from 0.8 V to 4.5 V. Fast transient response (≤10 MHz bandwidth) is achieved via high-gain error amplifier and optimized compensation, requiring only ≥1 µF ceramic output capacitance for stability.

Key Specifications

Pinout & Package

LD49150PT08R is housed in a thermally enhanced PPAK DFN6 (3×3 mm) package with exposed thermal pad soldered to PCB ground plane for effective heatsinking. The package complies with ECOPACK® environmental standards and supports reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A8300RGRT and ADM7172ACPZ-R7, LD49150PT08R uniquely supports 0.8 V adjustable output from 1.4 V VIN using dual-supply architecture-enabling designs where intermediate rail voltage is constrained by battery or energy-harvesting sources.

Availability

LD49150PT08R is available at Aetrix Electronics and suitable for graphics processor core supply, PC add-in card power, and microprocessor core voltage applications requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant packaging.

Supply support for LD49150PT08R 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 headquartered in Geneva, Switzerland, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

LD49150PT08R belongs to ST's high-performance LDO portfolio targeting low-voltage, high-current digital power rails-specifically engineered for microprocessor, GPU, and FPGA core supply where ultra-low dropout and fast transient response are critical.

FAQ

What is the minimum output capacitance required for stability?

The LD49150PT08R requires a minimum 1 µF ceramic capacitor (X5R/X7R) on the VOUT pin for guaranteed stability across temperature and load. A 10 µF capacitor is recommended for optimal transient response, especially when VIN exceeds 4 V to mitigate parasitic inductive overshoot during short-circuit events.

How does the dual-supply architecture improve performance?

The separate VBIAS input powers the error amplifier, reference, and control circuitry independently of VIN, allowing stable operation even when VIN drops to 1.4 V. This decoupling preserves PSRR, bandwidth, and regulation accuracy-unachievable with single-supply LDOs operating near dropout.

Can the EN pin be left floating?

No. The EN pin must never be left floating: it has no internal pull-up or pull-down. If unused, tie EN directly to VIN to ensure continuous operation. Leaving it unconnected risks erratic enable/disable behavior due to noise coupling, potentially causing system reset or brownout.

What thermal considerations apply to the PPAK package?

The PPAK package relies on PCB copper area for heatsinking: the exposed thermal pad must be soldered to a solid GND plane. For 1.5 A continuous load at 125°C ambient, ≥4 cm² of 2-oz copper (inner or bottom layer) is required. θJA drops from ~100°C/W (no copper) to ~40°C/W with adequate layout-preventing thermal shutdown.