500-mA, 40-V, adjustable linear voltage regulator

The LM317M and LM317MQ are adjustable

floating, positive-voltage regulators capable of supplying an output current of 0.5A

over an output voltage range of 1.25V to 37V. The device requires only two external

resistors to set the output voltage. The device features a typical line regulation

of 0.01% and typical load regulation of 0.1%. The device includes current limiting,

thermal overload protection, and safe operating area protection.

The device is a floating regulator

meaning there is no device ground terminal. Quiescent current flows to the load

instead of being wasted flowing to ground. Regulated output voltage of hundreds of

volts is possible if the maximum input to output differential does not exceed 37V at

any time. The device can function as a floating current source controlled by a

single resistor.

Additionally, the device does not need

an output capacitor for stable operation across the load current range. Optionally,

the transient performance of the device can be improved using an electrolytic or

tantalum output capacitor. Bypass the ADJUST pin with any type of capacitor to

achieve high ripple-rejection ratios.