EL6252C

Features:

• Mini-Small Package Outline
• Voltage-controlled output current source requiring one external set resistor per channel
• Current-controlled output current source.
• Rise time = 1.0 ns
• Fall time = 1.1 ns
• On chip oscillator with frequency and amplitude control by use of external resistors to ground
• Oscillator to 500 MHz
• Oscillator to 100 mA pk/pk
• Single +5V supply (±10%)
• Current amplification = 100
• CMOS control signals



Application

• MO drives
• Mini-Disc drives
• Writable optical drives
• Laser diode current switching



Pinout




Description

   The EL6252C is a high-performance two channel laser diode current amplifier that provides controlled current to a grounded laser diode. The write amplifier can provide over 200mA of DC or pulsed current. The R and W channels have switching speeds of approximately one nanosecond rise/fall time and are summed together at the IOUT output. 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 I_OUT.

   An on-chip 500 MHz oscillator EL6252C is provided to allow current modulation when in the read mode. This is turned on when the OSCEN pin is held high (floating not recommended). Complete control of amplitude and frequency is set by two external resistors connected to ground at pins RFREQ and RAMP (see graphs in this data sheet for further explanation).

   Write current pulses EL6252C appear when an 'L' signal is applied to the OUTENW pin.

   The external resistors EL6252C allow the user to accurately and independently set each amplifier transconductance by applying a voltage to each resistor, without restriction on the voltage range, thus ensuring broad voltage DAC compatibility. Alternatively, the IIN pin can be biased from a current DAC or other current source.