The IC TL783 is a 3 terminal high voltage regulator that can be used for getting a continuously variable output between 1.25 V to 125 V DC.
The device has an in-built DMOS MOSFET which enables the user to obtain a decent current at around 700 mA for the entire voltage range.
The IC becomes very useful in high-voltage applications where other typical voltage regulator such as LM338 etc seem greatly ineffective.
The IC TL 783 is extremely good with its high voltage regulation feature due to its state-of-the-art technology that includes standard bipolar circuitry along with a special high-voltage double diffused MOSFET output stage.
With these advanced layouts the device is able to ideally adapt to voltages at much higher levels which other BJT based designs simply fail.
Due to the elimination of secondary-breakdown and thermal-runaway characteristics, which are normally a part of typical BJT based outputs, the TL783 is able to execute an optimal overload protection even while working with potentials up to 125 V input-output differential.
The device is further packed with many outstanding features such as over-current limiting, safe-operating-area (SOA) protection, and thermal shutdown.
The above mentioned protection features remain active even in a situation where the ADJ pin of the IC is accidentally left open.
How the IC Workis
The IC TL783 high voltage regulator works with just a couple of external resistors in order to process the intended voltage regulation at its output pinout.
The regulator circuit may demand a capacitor across its input +/- terminals if the input supply source is at a considerable distance from the IC. On the other hand a capacitor across the output terminal may become essential for eliminating spikes and other form of short voltage transients.
The chip offers superb ripple rejection even in the absence of a bypass capacitor at its ADJ pinout
Reference: http://www.ti.com/lit/ds/symlink/tl783.pdf