50 - 400mA LM358 Constant Current Driver, 3.5 -5.0V - Hand-held lasers and Modules V2

Specification

• Type : Low drop-out linear regulator, precision current source
• Applications: 808nm diodes 20 - 300mW, 650-660nm red diodes 20-200mW
• Input Voltage: 3.0 – 5.5V
• Output Current Range: 50-400mA
• Dimensions: 11 x 20 mm

Notes on Operation

1. The LM358 is a single-ended dual op-amp that allows the circuit to regulate current through a single side of the power circuit, in this case the power –ve connection to the LD- connection regulates the drive current. Power +ve is connected directly to LD+.
2. These drivers can be configured to by-pass the on-board switch by connecting the –ve power supply to the ‘power –ve unswitched’ connection or if the switching action is required the centre ‘power –ve switched’ connection can be used.
3. The positive power supply can connect either to the ‘power +ve’ solder pad on the board, typically used for laser modules or (for case +ve or case not connected laser diodes) the case pin of the laser diode can be used to make the connection. The case pin connection method is typically used in green laser pointers where the laser pointer body (and hence the diode casing) connected to battery +ve and the battery –ve connects via a spring to the power -ve switched board pad.