peculiarity
Guaranteed 1% output voltage tolerance (LM317A)
Maximum guarantee. 0.01%/V Line Regulation (LM317A)
Maximum guarantee. 0.3% load regulation (LM117)
Ensures an output current of 1.5A
Drops to adjustable output of 1.2V
Constant temperature and current limit
P+ Product enhancement testing
80 dB ripple suppression rate.
Output short-circuit protection
illustrate
The actively adjustable three-terminal regulator LM117 series can provide an output range from 1.2V to 37V, exceeding 1.5A. They are very easy to use, requiring only two external resistors to set the output voltage. In addition, existing lines and load regulation are better than standard fixed voltage regulators. Additionally, the LM117 is packaged in a standard transistor, making it easy to install and handle packages.
In addition to outperforming fixed voltage regulators, the LM117 series offers complete overload protection only in ICs. This includes current limiting on the chip, overheating protection, and safeguarding the safe zone. All overload protection circuits remain fully functional, even if the terminal is disconnected when adjusted.
Normally, no capacitor is required unless the device is located at the slave input filter capacitor, in which case the input bypass needs to be more than 6 inches. An optional output capacitor can be added to improve transient response. Adjusting the terminal can bypass and achieve very high ripple rejection ratios, which is difficult to achieve with standard three-terminal regulators.
Besides replacing fixed regulators, the LM117 is very useful in a variety of other applications. Since the regulator is "floating," only the input to differential output voltage can be observed. A power supply of several hundred volts can be regulated for long-term maximum input differential output without exceeding the standard, thus avoiding short-circuit output.
Additionally, it allows for a particularly simple adjustable switching regulator, a programmable regulated output, or by adjusting the fixed resistor connecting pins and outputs, allowing the LM117 to serve as a precise current regulator. Tighten the adjustment of the terminal ground, and most loads can output 1.2V with very low output current, which can be done electronically.
For applications requiring higher output current, the LM150 series (3A) and LM138 series (5A) datasheets. For the negative addition, see the LM137 series datasheet.