L79L05ACZ

Overview

The L79L05ACZ 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 -7 V to -30 V and features thermal overload protection and short-circuit protection. It is housed in a TO-92 package with three pins and supports an operating junction temperature range of 0 °C to 125 °C.

Feature Summary

• Provides fixed negative voltage regulation for local or on-card applications
• Includes internal current limiting and thermal shutdown protection mechanisms
• Requires no external components for basic operation
• Offers improved output impedance compared to Zener diode/resistor combinations

Applications

• Local or on-card regulation for eliminating noise and distribution problems associated with single-point regulation
• Replacement for Zener diode/resistor combinations requiring lower quiescent current and lower noise
• Use with power pass elements to construct high-current voltage regulators

Procurement Notes

Verify that the specific part number matches the required AC tolerance variant (-5% output voltage accuracy) rather than the C variant (-10%). Confirm the TO-92 through-hole package configuration aligns with the PCB footprint requirements. Ensure the ordering suffix corresponds to the intended bulk or tape-and-reel packaging format as specified in the manufacturer's ordering information table.

Selection Notes

Select this component when a fixed negative voltage supply is required for low-to-moderate current loads up to 100 mA. Consider the thermal resistance characteristics of the TO-92 package and ensure adequate heat dissipation measures are implemented if the power dissipation approaches internal limits. Verify that the input voltage remains within the specified maximum rating of -30 V to prevent damage.

Part Context

The L79L05ACZ belongs to the L79L series of three-terminal negative voltage regulators. This family includes variants offering different fixed output voltages such as -8 V, -12 V, and -15 V. The series is designed for general-purpose regulation tasks where simplicity and reliability are prioritized, utilizing internal circuitry to protect against overcurrent and overheating conditions without external support components.

Replacement Considerations

Direct pin-compatible substitutes within the same series include other L79LxxACZ variants for different voltage outputs. Cross-manufacturer equivalents may exist but require verification of electrical parameters and pinout configurations.