资 源 简 介
The EL6211 is a three-channel laserdiode current amplifier that providescontrolled current to a grounded laserdiode. Channels 2 and 3 should be used as the writechannels, with switching speeds of less than twonanoseconds rise/fall TIme. All three channels are summedtogether at the IOUT output, allowing the user to createmulTIlevel waveforms in order to opTImize laser diodeperformance. The level of the output current is set by ananalog voltage applied to an external resistor which convertsthe voltage into a current at the IIN pin (virtually ground).An on-chip 500MHz oscillator is provided to allow outputcurrent modulaTIon when in any mode. This is turned onwhen the OSCEN pin is held high. Complete control ofamplitude and frequency is set by two external resistorsconnected to ground at pins RFREQ and RAMP (see graphsin this data sheet for further explanation).Output current pulses are enabled when an ‘L’ signal isapplied to the OUTEN pin. No output current flows whenOUTEN is ‘H’, and additional laser diode protection isprovided since the OUTEN input will float high when open.Complete IOUT shutoff is also achieved by holding theENABLE pin low, which will override the OUTEN controlpins.The external resistors allow the user to accurately andindependently set each amplifier transconductance byapplying a voltage to each resistor, without restriction on thevoltage range, thus ensuring broad voltage DACcompatibility. Alternatively, the IIN pin can be biased from acurrent DAC or other current source.
