EL6238
Dual 4-Channel Driver with Oscillator
Typical Diagram
Key Features
- 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 100mAP-P
- Single +5V supply (±10%)
- Chip enables for power savings
- Pb-free available (RoHS compliant)
Description
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 IOUT pin. Various waveforms can be generated where the amplitude is determined by the currents flowing into IINR, IIN2, IIN3, and IIN4. The timing is determined by the signals at OUTEN2, OUTEN3, and OUTEN4. The oscillator is enabled when OSCEN is high. The amplified IINR 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 IINR, IIN2, IIN3, and IIN4 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 IOUT1 is selected. OUTENR enables read and oscillator current.
The RF oscillators frequency is determined by RFREQ1 or RFREQ2, and its amplitude by RAMP1 or RAMP2.
Applications
- Super Combo drives
