STMicroelectronics L78L06ACZ

Overview

L78L06ACZ from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 6 V output at up to 100 mA, featuring internal current limiting, thermal overload protection, and short-circuit protection. It requires no external components and is commonly used for local on-card regulation in microcontroller power rails, sensor interface supplies, and low-power analog circuitry where noise rejection and stability are critical.

For engineers reviewing the L78L06ACZ datasheet, L78L06ACZ pinout, L78L06ACZ application, or L78L06ACZ equivalent, this device is selected for cost-sensitive, space-constrained designs requiring ±4% output accuracy, dropout voltage of 1.7 V, and operation across 0–125 °C junction temperature range without heatsinking.

Technical Context

The L78L06ACZ employs a monolithic bipolar silicon design with built-in thermal shutdown and foldback current limiting, enabling robust operation under fault conditions. Its architecture eliminates the need for external compensation or bypass capacitors beyond standard input/output decoupling (0.33 µF and 0.1 µF).

It operates as a fixed-output series pass regulator with a typical quiescent current of 6 mA at 25 °C and maintains output regulation over input voltages from 8.5 V to 20 V, supporting applications where input ripple and line variation must be suppressed before sensitive downstream circuitry.

Key Specifications

Pinout & Package

Supplied in TO-92 package (3-pin plastic transistor-style housing), with standardized pinout: Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN. The package supports through-hole mounting and provides adequate thermal dissipation for ≤100 mA loads without heatsink under ambient conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L06ACZ and MC78L06ACP, the L78L06ACZ delivers superior supply rejection (up to 46 dB) and lower output noise (50 µV), making it optimal for noise-sensitive analog and mixed-signal applications where regulation fidelity outweighs extended temperature range or automotive qualification.

Availability

L78L06ACZ is available at Aetrix Electronics and suitable for industrial sensor nodes, microcontroller core supplies, low-power analog signal chains, and on-card local regulation requiring stable component supply across long-lifecycle embedded programs.

Supply support for L78L06ACZ 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The L78L series belongs to ST's legacy linear regulator product line, engineered specifically for cost-effective, reliable local voltage regulation in space- and power-constrained applications where simplicity and ruggedness are prioritized over ultra-low IQ or adjustable output.

FAQ

What is the minimum input voltage required for stable 6 V output from L78L06ACZ?

The L78L06ACZ requires a minimum input voltage of 8.5 V to maintain regulation under all operating conditions, based on its 1.7 V dropout voltage specification and guaranteed performance across 0–125 °C junction temperature. Input below 8.5 V risks output collapse or unregulated behavior, especially at full 100 mA load or elevated temperature.

Can L78L06ACZ be used with ceramic output capacitors?

Yes-L78L06ACZ is stable with ceramic output capacitors of 0.1 µF or greater, as confirmed in ST's datasheet Figure 27 (stability vs. ESR). Unlike older 78L regulators, it does not require minimum ESR and avoids oscillation with low-ESR ceramics, simplifying layout and improving transient response in modern designs.

Does L78L06ACZ include reverse-polarity protection?

No-the L78L06ACZ lacks integrated reverse-voltage protection. Applying reversed polarity to VIN or VOUT can cause permanent damage. External protection (e.g., series diode on VIN or parallel TVS) must be added if reverse input is possible in the target application.

How does thermal performance differ between TO-92 and SO-8 packages for L78L06ACZ?

In TO-92, R_thJA is 200 °C/W (no heatsink), limiting continuous 100 mA operation to <25 °C ambient. In SO-8 with 6 cm² copper pour, R_thJA drops to 55 °C/W, enabling full-rated current up to 85 °C ambient. Package selection must match thermal budget-not electrical specs-as both share identical regulation characteristics.