The EL6253C is a high-performance three channel laser diode current amplifier that provides controlled current to a grounded laser diode. Amplifiers R and 2 can provide up to 120 mA per channel of DC or pulsed current whereas amplifier 3 can provide up to 240 mA. Channels 2 and 3 must be used as the write channels, with switching speeds of approximately one nanosecond rise/fall time. All three channels are summed together at the IOUT output, allowing the user to create multilevel waveforms in order to optimize laser diode performance. The level of the output current is set by an analog voltage applied to an external resistor which converts the voltage into a current at the IIN pin (virtually ground). The current seen at this pin is then amplified by 100X to become a current source at pin IOUT.