peculiarity
Guaranteed 1% Output Voltage Tolerance (LM317A)
Guaranteed maximum. 0.01%/V Line Regulation (LM317A)
Guaranteed maximum. 0.3% Load Regulation (LM117)
Guaranteed 1.5A output current
Drops to an adjustable output of 1.2V
Current limit with constant temperature
P+ product enhancement testing
80 dB ripple rejection.
Output short-circuit protection
illustrate
The LM117 series of actively adjustable three-terminal regulators is capable of providing an output range of more than 1.5A from 1.2V to 37V. They are very easy to use and only require two external resistors to set the output voltage. In addition, both line and load regulation are better than standard fixed regulators. In addition, the LM117 is packaged in standard transistors, making it easy to install and handle packages.
In addition to higher performance than fixed regulators, the LM117 series provides complete overload protection only in ICs. Includes current limit, overtemperature protection and protection of safe zones on the chip. All overload protection circuits remain fully functional, even if the adjustment terminal is disconnected.
Under normal circumstances, no capacitor is required unless the device is located in a slave input filter capacitor, in which case an input bypass of more than 6 inches is required. An optional output capacitor can be added to improve transient response. Trimming the terminal can bypass to achieve a very high ripple rejection ratio, which is difficult to implement with a standard three-terminal regulator.
In addition to replacing a fixed regulator, the LM117 is useful in a variety of other applications. Since the regulator is "floating" and can only see the input to the differential output voltage, a power supply of several hundred volts can be supervised for a long time without exceeding the standard, that is, avoiding short-circuit output.
In addition, it enables a particularly simple adjustable switching regulator, a programmable regulated output, or by adjusting the connection between the pin and the output fixed resistor, the LM117 can be used as a precision current regulator. Clamping to adjust the terminal ground which programs most loads draw to 1.2V output current is very small and can be passed through electronic shutdown supplies.
For applications requiring higher output current, the LM150 Series (3A) and LM138 Series (5A) datasheets. For negative additions, see the data sheet for the LM137 series.