LM317T/NOPB

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.
Because the regulator is floating and detects only the
input-to-output differential voltage, supplies of several
hundred volts can be regulated as long as the
maximum input-to-output differential is not exceeded.
That is, avoid short-circuiting the output.
By connecting a fixed resistor between the
adjustment pin and output, the LM117 and LM317-N
can be also used as a precision current regulator.
Supplies with electronic shutdown can be achieved
by clamping the adjustment terminal to ground, which
programs the output to 1.25 V where most loads draw
little current.