STMicroelectronics L78L06ACUTR

Overview

L78L06ACUTR from STMicroelectronics is a fixed-output +6 V, 100 mA positive linear voltage regulator in SOT-89 package, featuring ±4% output voltage tolerance at 25 °C (5.76–6.24 V), 1.7 V dropout voltage, and integrated thermal overload and short-circuit protection. It delivers stable local regulation for microcontroller I/O rails, sensor biasing, and low-power analog circuitry in industrial control and automotive body electronics.

For engineers reviewing the L78L06ACUTR datasheet, L78L06ACUTR pinout, L78L06ACUTR application, or L78L06ACUTR equivalent, this device serves as a drop-in replacement for legacy 6 V regulators requiring low quiescent current (6 mA typ. at 25 °C), high PSRR (39–46 dB at 120 Hz), and noise-sensitive operation (50 µV RMS output noise, 10 Hz–100 kHz).

Technical Context

The L78L06ACUTR implements a monolithic three-terminal architecture with internal current limiting, thermal shutdown, and no external compensation required. Its design targets local point-of-load regulation where input-to-output differential is ≥1.7 V and ambient temperature remains within 0–125 °C.

It operates across input voltages of 8.5–20 V (for 6 V output), maintains load regulation of ≤30 mV over 1–40 mA, and achieves line regulation of ≤100 mV when VI varies from 9–20 V - enabling robust performance in unregulated DC supplies and battery-derived rails.

Key Specifications

Pinout & Package

SOT-89 package: 3-pin surface-mount plastic package with exposed die attach pad for enhanced thermal dissipation (R_thJA = 55 °C/W with 6 cm² copper pour). Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L06ACZ, L78L06ACUTR provides better thermal management and tighter initial tolerance; versus TL750L06CD, it trades 2% accuracy and 15 µV noise reduction for direct SOT-89 compatibility and lower system-level integration effort.

Availability

L78L06ACUTR is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body electronics, embedded microcontroller I/O rails, and legacy equipment retrofits requiring stable component supply with consistent parametric performance across production batches.

Supply support for L78L06ACUTR 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.

L78L06ACUTR belongs to the L78L series of three-terminal positive voltage regulators, engineered for cost-effective, protected local regulation in space-constrained and thermally demanding environments - especially where reliability under fault conditions is essential.

FAQ

What is the minimum input voltage required for L78L06ACUTR to maintain regulation?

The L78L06ACUTR requires a minimum input voltage of 7.7 V to sustain 6 V output under full 100 mA load, based on its 1.7 V typical dropout voltage. At 40 mA load, input may be as low as 7.7 V; derating is recommended for worst-case temperature and tolerance variation. Operation below 8.5 V input is not characterized per datasheet Table 14.

Can L78L06ACUTR be used in parallel to increase output current?

No - L78L06ACUTR is not designed for parallel operation. Its output voltage tolerance (±4%) and lack of current-sharing features cause unequal load distribution, risking thermal runaway in one device. For >100 mA, use a single higher-current regulator (e.g., L7806CD2T) or add an external pass transistor per Figure 14 in DS0424.

Is a heatsink required for continuous 100 mA operation in SOT-89 package?

A PCB copper pour of ≥6 cm² connected to the exposed tab is mandatory for 100 mA continuous operation at ambient temperatures up to 70 °C. Without it, junction temperature exceeds 125 °C even at 40 mA. The SOT-89's R_thJA drops from 200 °C/W (TO-92) to 55 °C/W with proper layout - making heatsinking achievable via standard FR4 copper, not mechanical heatsinks.

Does L78L06ACUTR require both input and output capacitors?

Yes - STMicroelectronics specifies a 0.33 µF ceramic capacitor at the input (within 5 mm of Pin 1) and a 0.1 µF ceramic capacitor at the output (within 5 mm of Pin 3) for stability, transient response, and EMI suppression. Omitting either risks oscillation, overshoot, or failure to reject input ripple, as confirmed in Figure 13 and Section 6 of DS0424 Rev 30.