STMicroelectronics LD1084D2M-R

Overview

LD1084D2M-R from STMicroelectronics is a 5A low-dropout positive voltage regulator in D2PAK package, delivering fixed 1.5V output with ±1% tolerance at 25°C, 1.3V typical dropout at 5A load, and operation across –40°C to +125°C junction temperature. It enables high-efficiency power delivery in space-constrained industrial DC-DC stages where thermal margin and load regulation stability are critical.

For engineers reviewing the LD1084D2M-R datasheet, LD1084D2M-R pinout, LD1084D2M-R application, or LD1084D2M-R equivalent, key selection considerations include dropout voltage under full-load conditions, quiescent current behavior across input voltage range, thermal resistance (R_thJC = 3°C/W), output tolerance over temperature, and compatibility with minimal 10µF output capacitance for stability.

Technical Context

The LD1084D2M-R uses an NPN pass transistor architecture-unlike PNP-based regulators-so its quiescent current flows into the load rather than being wasted, improving efficiency at light loads. Internal trimming ensures tight ±1% output voltage accuracy at 25°C and ±2% over full temperature range.

It integrates thermal shutdown and internal current limiting, supports adjustable configurations via external resistors (though LD1084D2M-R is fixed 1.5V), and maintains stability with only a 10µF tantalum output capacitor-no ESR constraints or additional compensation required.

Key Specifications

Pinout & Package

D2PAK (TO-263) package: thermally enhanced surface-mount variant with exposed metal tab for PCB copper pour heat sinking; compatible with standard reflow profiles and high-power layout practices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1084D2M-R, LD1085D2T-R offers identical mechanical and thermal behavior but targets 5 V systems, while TLV1117-15CDR trades current capability and thermal robustness for compactness-making it unsuitable as a drop-in replacement in high-power applications.

Availability

LD1084D2M-R is available at Aetrix Electronics and suitable for industrial PLCs, FPGA power systems, SCSI-2 termination networks, and motor driver logic rails requiring stable component supply with full traceability and long-lifecycle support.

Supply support for LD1084D2M-R 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, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The LD1084 series belongs to ST's high-current linear regulator product line, engineered specifically for industrial power conversion where thermal resilience, output accuracy, and reliability under sustained load are prioritized over switching efficiency.

FAQ

What is the minimum input voltage required for LD1084D2M-R to regulate 1.5 V at 5 A?

The minimum input voltage is 2.8 V, based on the typical 1.3 V dropout voltage at 5 A load. At worst-case 1.5 V dropout (guaranteed maximum), input must be ≥3.0 V. Input voltage must also remain within the absolute maximum rating of 30 V and avoid exceeding thermal limits under continuous operation.

Can LD1084D2M-R be used with ceramic output capacitors?

Yes, but ≥22 µF ceramic capacitance is required for stability-versus the 10 µF minimum for tantalum. Ceramic capacitors have lower ESR, which can cause phase margin loss; ST recommends verifying loop stability via load transient testing or using the manufacturer's recommended RC snubber if ringing occurs above 100 kHz.

Does LD1084D2M-R require an input bypass capacitor?

While not strictly mandatory, a 10 µF aluminum or tantalum input capacitor placed within 1 cm of the VIN pin is strongly recommended to suppress high-frequency noise from upstream sources (e.g., switchers) and prevent instability during fast load transients. Without it, line regulation degrades above 10 kHz and startup overshoot may exceed 10%.

How does the thermal shutdown behave during overload conditions?

When junction temperature exceeds ~150°C, the device disables the pass transistor and holds output at zero until temperature drops below ~135°C hysteresis threshold. Shutdown is fully automatic and self-recovering-no external reset or latch is needed. Recovery time depends on PCB thermal mass and airflow, typically 100–500 ms in standard 2-layer FR4 layouts.