L79L05ABZ-AP

Overview

The L79L05ABZ-AP is a three-terminal negative linear voltage regulator from the L79L series, manufactured by STMicroelectronics. It provides a fixed output voltage of -5 V with an output current capability up to 100 mA. The device operates within a DC input voltage range of -30 V and supports an operating junction temperature range of -40 °C to +125 °C. Key electrical characteristics include a typical quiescent current of 6 mA at 25 °C, a dropout voltage of 1.7 V, and supply voltage rejection of 49 dB at 120 Hz. It is housed in a TO-92 package.

Feature Summary

• Integrated thermal overload protection and short-circuit protection for robust operation.
• Designed as a direct replacement for Zener diode/resistor combinations, offering improved output impedance and lower noise.
• Requires no external components for basic fixed voltage regulation applications.

Applications

• Local or on-card regulation to eliminate noise associated with single-point regulation.
• Negative power supply generation in electronic circuits.
• Replacement for discrete Zener diode and resistor voltage reference networks.

Procurement Notes

Verify that the specific part number matches the required tolerance grade; the 'AB' suffix indicates a ±5% output voltage selection. Confirm the package type corresponds to the TO-92 form factor with lead-free construction. Ensure the ordering code aligns with the desired packaging configuration, such as bulk bags or tape and reel, as specified in the manufacturer's official ordering information tables.

Selection Notes

Select this component when a stable negative voltage rail is required for low-to-moderate current loads up to 100 mA. The wide operating temperature range makes it suitable for industrial environments. Consider the dropout voltage requirements relative to the minimum input voltage to ensure proper regulation. Verify that the thermal resistance characteristics of the TO-92 package are sufficient for the expected power dissipation under load conditions.

Part Context

This component belongs to the L79Lxx series of three-terminal negative regulators. The series includes variants with different fixed output voltages, such as -8 V, -12 V, and -15 V. The L79LxxAB variant specifically denotes the version with tighter voltage tolerance compared to the L79LxxAC version. These regulators are designed for general-purpose power management tasks requiring reliable negative voltage sources.

Replacement Considerations

Direct functional substitutes within the same series include L79L08ABZ-AP (-8V), L79L12ABZ-AP (-12V), and L79L15ABZ-AP (-15V). Cross-series replacements like the L79 series (larger packages) offer higher current capabilities but require different PCB footprints. Ensure any substitute maintains the same polarity, pinout configuration, and thermal performance characteristics.

FAQ

What is the maximum DC input voltage for the L79L05ABZ-AP?

The maximum absolute DC input voltage is -30 V.

Does the L79L05ABZ-AP require external capacitors to function?

No external components are strictly required for basic operation, though input and output capacitors are typically recommended for stability in practical applications.

What is the typical quiescent current at room temperature?

The typical quiescent current is 6 mA at a junction temperature of 25 °C.