The LM117 and LM317-N series of adjustable 3-pin positive voltage regulators are capable of supplying in excess of 1.5 A over a 1.25-V to 37-V output range and a wide temperature range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators.
The LM117 and LM317-N offer full overload protection such as current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected.
Typically, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors, in which case an input bypass is needed. An optional output capacitor can be added to improve transient response. The adjustment terminal can be bypassed to achieve very high ripple rejection ratios that are difficult to achieve with standard 3-terminal regulators.
• Typ. 0.1% Load Regulation
• Typ. 0.01%/V Line Regulation
• 1.5-A Output Current
• Adjustable Output Down to 1.25 V
• Current Limit Constant With Temperature
• 80-dB Ripple Rejection
• Short-Circuit Protected Output
• −55°C to 150°C Operating Temperature Range (LM117)
• Automotive LED Lighting
• Battery Chargers
• Post Regulation for Switching Supplies
• Constant Current Regulators
• Microprocessor Supplies