The EL6238 is a high performance, dual output, laser driver for writeable 'super-combo' CD - DVD drive. The ENA pin enables the chip, while the SEL1 pin selects the I_OUT pin. Various waveforms can be generated where the amplitude is determined by the currents flowing into I_INR, I_IN2, I_IN3, and I_IN4. The timing is determined by the signals at OUTEN2, OUTEN3, and OUTEN4. The oscillator is enabled when OSCEN is high. The amplified I_INR current of the selected channel is enabled when the ENA pin is high. The total output current is the sum of the read current, the enabled write currents, and the oscillator current when enabled.

Usually a voltage DAC will drive a resistor that is in series with the I_INR, I_IN2, I_IN3, and I_IN4 inputs. The resistor allows the user to optimize the current gain for each channel.

Output write current pulses are enabled when a low is applied to the OUTEN2, OUTEN3, or OUTEN4 pin. The write current will flow to the selected output. When SEL1 is high I_OUT1 is selected. OUTENR enables read and oscillator current.

The RF oscillators frequency is determined by R_FREQ1 or R_FREQ2, and its amplitude by R_AMP1 or R_AMP2.

• Two channels for CD or DVD
• Voltage-controlled output current source requiring one external set resistor per channel
• Rise time = 0.8ns
• Fall time = 0.8ns
• Channel 2 to 270mA max
• Channel 3 to 200mA max
• Channel 4 to 100mA max
• On-chip oscillator with frequency and amplitude control by use of external resistors to ground
• Oscillator frequency to 600MHz
• Oscillator amplitude to 100mA_P-P
• Single +5V supply (±10%)
• Chip enables for power savings
• Pb-free available (RoHS compliant)

• Super Combo drives