The 78XX can produce output current in excess of 1A when used with an adequate heat sink. The
78LXX series can provide up to 100mA, the 78MXX series can provide up to 500mA, and the
78TXX series can provide in excess of 3A.
The input voltage must be at least 2V above the output voltage in order to maintain regulation. The
circuits have internal thermal overload protection and short-circuit current-limiting features. Thermal
overload occurs when the internal power dissipation becomes excessive and the temperature of the
device exceeds a certain value.
PIN 1 - INPUT
2 - GROUND
3 - OUTPUT
Fig: (5.1.a) Pin Layout
Fig: (5.1.b) Standard configuration
Table (5.1) 78XX series
Fixed Negative Linear Voltage Regulators
The 79XX series is typical of three-terminals IC regulators that provide a fixed negative output
voltage. This series is the negative counterpart of the 78XX series and shares most of the same
features and characteristics. Fig: (5.2.a & b) and Table (5.2) indicate the pin layout; the standard
configuration and part numbers with corresponding output voltage that are available.