Negative linear regulator Li'lBoard page.
Model number: LB2.02.
Description: This board works as a regulator to provide a smooth, fixed negative voltage when supplied with a more negative voltage.
Applications:
•To produce your system's desired negative operating voltage, use with a L'il2.08 (Wall Wart input) which is wired so that its most positive voltage is connected to system ground.
•The board can be operated as a current sink (useful for high power LEDs); this mode is supported by the support software.
Features:
•The board is designed so that the resistors that determine the output voltage can be combinations of both through-hole or SMD devices. One use of this is to parallel a (high value) through-hole device to trim the output voltage in critical applications. Additionally, the terminals where the resistors are mounted can be used to configure a selectable voltage regulator, using a switch to ground, or using a potentiometer to make a variable regulator with a lower limit on voltage of about 1.25 V.
•The input voltage can be fed into the unit via an on-board diode or directly. The diode provides protection from reverse voltages, however it will add to the dropout voltage of the regulator.
•Either a TO-220 or a surface mount version of the regulator can be installed. (Without either type installed the board can also be wired up to a TO-3 socket for higher power applications. Even a TO-39 package can be accommodated if desired.)
•If it is desired to run the regulator in current source mode then a higher power resistor can be mounted. To do this use the terminal below R1, and the “-V” terminal at the top right of the board to connect the current-setting resistor.
•A heatsink can be mounted on the TO-220 package version.
Key components: LM337
Support page: Click here
Restrictions: Can only produce an output which is less negative than the input, less a further dropout voltage of about 1.5 V.
Images:
Click on image for full (PDF) schematic
Vin max: 40
Vin min: 2.5
Vout min: 1.25
Vout max: 37
SPI: N/A.
Tenth centers: YES