CYStech Electronics Corp.

Spec. No. : C513F3

Issued Date : 2003.05.24

Revised Date :2010.07.22

Page No. : 6/11

LM317F3

CYStek Product Specification

Fig 4. Ripple Rejection Test Circuit

Application Information

Basic Circuit Operation

The LM317 is a 3-terminal floating regulator. In operation, the LM317 develops and maintains a nominal

1.25V reference (Vref) between its output and adjustment terminals. This reference voltage is converted

The regulated output voltage is given by:

Vout=Vref

current is returned to the output terminal. This imposes the requirement for a minimum load current. If

the load current is less than this minimum, the output voltage will rise.

Since the LM317 is a floating regulator, it is only the voltage differential across the circuit which is

important to performance, and operation at high voltages with respect to ground is possible.

Fig 5. Basic Circuit Configuration