A laser diode current driver with photodiode sense amplifier for optical disk drive

A monolithic laser power amplifier is described. This IC drives a laser diode in a read/write optical disk system, accurately delivering up to 200 mA. The write pulses have less than 4-ns rise and fall times. Also included on the chip is a transimpedance amplifier which accepts the current from a laser power monitoring PIN photodiode and converts it to a voltage so that a servo system can maintain the correct read and write current levels. The IC is fabricated on a complementary bipolar process with a 6-GHz n-p-n f and a 1-GHz vertical p-n-p f.<
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