Adujstable output voltage as low as 1.2V.
Ensure 1.5A output current.
Typical linear adjustment rate of 0.01%.
0.1% typical load regulation.
80dB ripple rejection ratio.
Output short circuit protection.
Overcurrent, overtemperature protection.
Regulator safe operating area protection.
Standard three-terminal transistor package.
Voltage range LM117 / LM317 1.25V to 37V continuously adjustable
Fairchild Semiconductor LM317 and information: 
Manufactured by Fairchild Semiconductor, LM317 is a linear regulator.
Edit this paragraph the main parameters
Output voltage: 1.25-37V DC;
Output current: 5mA-1.5A;
chip has overheated, over-current, short circuit protection;
Maximum input - output voltage differential: 40V DC,
The minimum input - output voltage differential: 3V DC;
Ambient temperature: -10- + 85 ℃.
Storage temperature: -65- + 150 ℃.
LM317 as the output voltage of the variable three-terminal regulator integrated block, is an easy to use, widely integrated regulator blocks. Model 317 series regulator block a lot: for example LM317HVH, W317L and so on. Electronic enthusiasts often make the output voltage regulator block 317 a variable power supply.
Power supply output voltage can be calculated, Vo = 1.25 (1 + R2 / R1). Only from the formula itself, the resistance values R1, R2 can be arbitrarily set. However, as the power supply output voltage calculation formula, R1 and R2 are not arbitrarily set.
First, the output voltage range of the regulator block 317 is Vo = 1.25V-37V (high output voltage regulator block 317 as LM317HVA, LM317HVK the like, the output voltage range is Vo = 1.25V-45V), so that R2 / R1 the ratio of the range can only be 0-28.6.
Second regulator block 317 has a minimum stable operating current, and some information called minimum output current, and some information called minimal leakage current. The minimum value is generally stable operating current 1.5mA. Because different regulator block 317 manufacturers, different models, the minimum stable operating current is not the same, but generally not more than 5mA. When the minimum stable current output current regulator block is less than 317, 317 regulator block will not work. When the output current regulator block 317 is greater than the minimum stable operating current regulator block 317 can output stable DC voltage. (As shown), did not pay attention if the regulator block with 317 making the minimum stable power supply current regulator block 317, then you make the power supply may occur following irregularities: power supply output the load voltage and load voltage varied.
In the application, in order to stabilize the circuit operation, in general, need to connect a diode as a protective circuit to prevent high voltage capacitor discharge circuit 317 of the burn.