LMH6533 Datasheet | National Semiconductor

Description The LMH™ 6533 is a laser diode driver for use in bination DVD/CD recordable and rewritable systems. The part contains two high-current outputs for reading and writing the DVD (650 nm) and CD (780 nm) lasers. Functionality includes read, write and erase through four separate switched current channels. The channel currents are summed together at the selected output to generate multilevel waveforms for reading, writing and erasing of optical discs. The LVDS interface delivers DVD write speeds of 12x and higher while minimizing noise and crosstalk. The LMH6533 is optimized for both speed and power consumption to meet the demands of next generation systems. The part features a 150 m A read channel plus one 300 m A and two 150 m A write channels, which can be summed to allow a total output current of 500 m A or greater. The channel currents are set through four independent current inputs. The part is manufactured in National Semiconductor’s VIP10™ process, which features bonded wafer technology and trench isolation for very high switching speeds at low power levels. An on-board High-Frequency Modulator (HFM) oscillator helps reduce low-frequency noise of the laser and is enabled with the ENOSC pin. The fully differential oscillator circuit minimizes supply line noise, easing FCC approval of the overall system. The SELB pin (active HIGH) selects the output channel and oscillator settings. External resistors determine oscillator frequency and amplitude for each setting. The write and erase channels can be switched on and off through dedicated LVDS interface pins. Features n Fast switching: Rise and fall times < 0.8 ns n Low voltage differential signaling (LVDS) channels enable interface for the fast switching lines n Low output current noise: < 0.5n A/ n Dual output: Selectable by SELB pin (active HIGH) n Four independent current channels - Gain of 300, 300 m A write channel - Gain of 150, 150 m A low-noise read channel - Two gain of 150, 150 m A write channels - 500...