The MC79L00A series negative voltage regulators are inexpensive, easy to use and suitable for a wide range of applications requiring up to 100 mA. Like the more powerful MC7900 series negative regulators, this series has thermal shut-off and current limiting features that make it very rugged. In most applications, no external component is required for the operation.
Representative schematic diagram
The MC79L00A device is suitable for in-card regulation or any other application that requires moderate current levels to regulate negative voltages. These regulators offer substantial advantages over the normal resistance/Zener diode method.
MC79L00A series fixed voltage regulator design has thermal overload protection, when the power overload condition is too large closed circuit, internal short circuit protection, limit the circuit will pass the maximum current. In many low-current applications, compensating capacitors are not required.
Positive and negative regulator
However, if the voltage regulator is connected to a long power filter line, or the output load capacitance is large, it is recommended to use capacitor bypass voltage regulator input. Input bypass capacitors should be selected to provide good high frequency characteristics to ensure stable operation under all load conditions. 0.33F or larger tantalum, mylar or other capacitors with low internal impedance at high frequencies should be selected.
Standard Application
The bypass capacitor shall be installed on the shortest possible lead directly through the voltage regulator input terminal. Usually, good construction techniques are applied to minimize the grounding loop and lead resistance drop, since the regulator has no external induction leads. It is also recommended to bypass the output.
