What is the compliance voltage of a current driver?

The compliance voltage is the maximum voltage that a current driver can provide across its load while maintaining the requested current.

For example, if a laser diode needs 5 V to reach the desired current, the driver must have a compliance voltage higher than 5 V.

If the laser requires more voltage than the driver can provide, the current will not reach the requested value.

When selecting a current driver, check both the maximum output current and the compliance voltage required by your load.

For a laser diode, use the forward voltage at the intended operating current from the laser datasheet.

Can I increase the compliance voltage by increasing the supply voltage?

No, unless this is explicitly supported by the product documentation.

The supply voltage and the compliance voltage are different specifications. Applying a supply voltage above the specified range may damage the driver.

Can I connect two current-driver outputs in series to increase the compliance voltage?

Do not connect current-driver outputs in series unless the product documentation explicitly states that this is supported.

If you need a higher compliance voltage, use a driver designed for the required load voltage.