STMicroelectronics LD1086V33-DG

Overview

LD1086V33-DG from STMicroelectronics is a fixed-output 3.3 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, and internal thermal/overcurrent protection. It delivers stable power to microcontroller cores, FPGA I/O banks, and industrial sensor signal chains where input-to-output headroom is constrained.

For engineers reviewing the LD1086V33-DG datasheet, LD1086V33-DG pinout, LD1086V33-DG application, or LD1086V33-DG equivalent, key selection criteria include dropout voltage under 1.5 A load, output accuracy across –40 °C to +125 °C, quiescent current behavior, stability with 10 µF output capacitance, and thermal resistance in DPAK (R_thJA = 33 °C/W).

Technical Context

The LD1086V33-DG implements a PNP-based LDO architecture with on-chip trimming for tight output voltage accuracy. Its reference voltage is internally set to 1.25 V, enabling precise 3.3 V regulation via resistor-free fixed-output configuration. Dropout is maintained below 1.5 V up to 1.5 A, with quiescent current flowing into the load-not wasted as bias-improving efficiency over legacy regulators.

Thermal shutdown activates at junction temperatures exceeding 150 °C, and short-circuit current is dynamically limited to 1.5–2.3 A depending on dropout conditions. The device requires only a 10 µF minimum ceramic or tantalum output capacitor for stability and exhibits 79 dB supply voltage rejection at 120 Hz with 25 µF output capacitance.

Key Specifications

Pinout & Package

LD1086V33-DG is housed in a surface-mount DPAK (TO-252) package with exposed thermal pad connected to the output terminal. The package provides low thermal resistance (R_thJA = 33 °C/W) and is compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with TLV1117-33IDCYR and TPS7A4701RGWR, LD1086V33-DG uniquely balances 1.5 A capability, DPAK thermal performance, and cost-effective fixed-output simplicity-making it optimal for industrial and automotive applications demanding robustness over ultra-low noise or minimal footprint.

Availability

LD1086V33-DG is available at Aetrix Electronics and suitable for industrial automation controllers, automotive body electronics, medical diagnostics hardware, and networking infrastructure requiring stable component supply with long-term manufacturability.

Supply support for LD1086V33-DG 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, designing and manufacturing analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

LD1086V33-DG belongs to ST's LD1086 series of high-current LDOs engineered for reliability in harsh environments-targeting applications where dropout, accuracy, and thermal resilience outweigh ultra-low-noise or ultra-low-I_Q requirements.

FAQ

What is the minimum input voltage required for LD1086V33-DG to maintain regulation?

The minimum input voltage is 4.6 V: 3.3 V output plus 1.3 V typical dropout at 1.5 A load. At lighter loads, dropout decreases-e.g., ~0.6 V at 500 mA-allowing operation from as low as 3.9 V. Input must remain ≤30 V per absolute maximum rating.

Can LD1086V33-DG be used with ceramic output capacitors?

Yes-ST specifies stability with ≥10 µF ceramic (X5R/X7R) or tantalum capacitors. ESR is not critical due to internal compensation; however, a 1 µF ceramic bypass capacitor near the input pin is recommended for high-frequency transient suppression.

Does the DPAK thermal tab require solder connection to PCB copper?

Yes-the exposed thermal pad is electrically connected to the output (V_OUT) and must be soldered to a dedicated thermal land with ≥4 thermal vias to an inner ground or power plane. This achieves the specified R_thJA = 33 °C/W; omitting it degrades thermal performance by >20 °C/W.

How does LD1086V33-DG behave during short-circuit events?

It enters current-limit mode with foldback characteristics: short-circuit current drops to ~50–200 mA once dropout falls below ~2 V, reducing power dissipation. Thermal shutdown activates if junction temperature exceeds 150 °C, and the device automatically recovers once cooled below ~140 °C.