STMicroelectronics LD1086DT50TR

Overview

LD1086DT50TR from STMicroelectronics is a fixed-output 5.0 V, 1.5 A low-dropout linear voltage regulator in DPAK package, featuring ±1% output tolerance at 25 °C, 1.3 V typical dropout at full load, internal thermal and current limiting, and operation from −40 °C to +125 °C. It delivers stable power to microcontroller cores, FPGA I/O banks, and industrial sensor signal chains where precision and thermal robustness are critical.

For engineers reviewing the LD1086DT50TR datasheet, LD1086DT50TR pinout, LD1086DT50TR application, or LD1086DT50TR equivalent, this page provides verified technical context, validated pin functions, real-world application constraints, and confirmed alternative options for 5 V LDO replacement in high-reliability embedded systems.

Technical Context

The LD1086DT50TR implements a PNP-based pass transistor architecture with on-chip trimming for tight output voltage accuracy. Its reference voltage is internally set to 1.25 V, enabling fixed 5.0 V output via resistor-free configuration - eliminating external feedback network errors and layout sensitivity.

Quiescent current flows entirely into the load (not wasted as base current), improving efficiency over legacy PNP regulators. Dropout behavior is monotonic and guaranteed ≤1.5 V across temperature and load, supporting input voltages as low as 6.5 V while maintaining regulation at 1.5 A.

Key Specifications

Pinout & Package

LD1086DT50TR uses the DPAK (TO-252) surface-mount package with exposed thermal pad. The package features three terminals: Input (IN), Output (OUT), and Ground (GND). The tab is electrically connected to the output pin, requiring isolation from PCB ground planes unless intentionally tied to output potential.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed 5 V LDO applications.

Compared with LD1117DT50TR and TLV1117-50CDR, the LD1086DT50TR uniquely combines 1.5 A capability, ±1% accuracy, and DPAK thermal performance-making it the only option among the three qualified for sustained 1.5 A operation in extended temperature industrial applications.

Availability

LD1086DT50TR is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, medical patient monitors, and test equipment requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LD1086DT50TR 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 silicon solutions for automotive, industrial, and power management applications.

The LD1086 series belongs to ST's high-current, precision LDO portfolio, engineered specifically for industrial automation and automotive subsystems demanding tight voltage regulation, wide temperature operation, and robust thermal performance.

FAQ

What is the minimum input voltage required for LD1086DT50TR to maintain 5.0 V regulation at 1.5 A?

The minimum input voltage is 6.5 V, calculated as 5.0 V + 1.5 V maximum dropout. At 1.5 A and 125 °C junction temperature, dropout remains ≤1.5 V per datasheet Table 6, ensuring regulation down to 6.5 V input. Below this, output voltage drops linearly with input.

Can LD1086DT50TR be used with ceramic output capacitors only?

Yes. The device is stable with ≥10 µF ceramic output capacitors and has no minimum ESR requirement. This eliminates the need for tantalum or aluminum electrolytic capacitors, reducing size, cost, and failure risk in high-reliability designs.

Is the thermal pad on the DPAK package electrically connected, and how should it be handled on the PCB?

Yes-the exposed thermal pad is internally connected to the OUT pin. It must be soldered to a dedicated copper pour tied to the 5 V output net, not to ground. This ensures optimal thermal conduction while maintaining correct electrical potential and avoiding short circuits.

Does LD1086DT50TR include reverse polarity or reverse current protection?

No. The device lacks internal reverse-battery or reverse-current blocking. If the output voltage exceeds the input (e.g., during hot-swap or backup battery scenarios), current will flow backward through the pass transistor, potentially damaging upstream circuitry. An external Schottky diode is required for such use cases.