M66515FP Datasheet, PDF (1/12 Pages) Mitsubishi Electric Semiconductor – LASER-DIODE DRIVER/CONTROLLER

M66515FP
Laser Diode Driver/Controller
REJ03F0084-0100Z
Rev.1.0
Sep.22.2003
Description
The M66515 is a laser diode driver/controller that performs drive and controls the laser power control of a type of
semiconductor laser diode the anode of which is connected, with the cathode of a photodiode for monitoring, to a stem
in which the semiconductor laser diode anode and monitoring photo diode cathode are connected to the stem.
This IC has a sink-type laser driving current output pin, and can drive a laser diode with a bias current of up to a
maximum 30 mA and with switched currents of up to 120 mA, switched at rates of up to 40 Mbps.
The IC incorporates a sample hold circuit, so that a self-APC (Automatic Power Control) system, which does not
require external laser power control, can be realized.
Features
• Internal sample-and-hold circuit for self-APC configuration
• High-speed switching (40 Mbps)
• High driving currents (150 mA max)
• Settable bias current (30 mA max)
• Single 5 V power supply
Applications
• Equipment employing semiconductor laser diodes
Function Overview
The M66515 is a laser diode driver/controller which drives and controls the laser power of a semiconductor laser diode
(LD) the anode of which is connected, with the cathode of a photodiode (PD) for monitoring, to a stem (among
Mitsubishi lasers, N type models).
LD driving and laser power control are executed by connecting an external capacitance to the C_H pin and applying a
reference voltage to the V_r pin.
The PD current occurring when a LD emits light flows through a resistance connected across 1RM and 2RM, resulting
in a potential difference (V_M). This V_M is compared with the voltage applied to the V_r pin, and when V_M<V_r, a constant
current source from the C_H pin flows to charge the external capacitor. When V_M>V_r, a constant current sink from the
C_H pin causes the charge on the external capacitor to be discharged.
This operation is performed when the S/H input is "L" (sample); when the S /H input is in the "H" state, the C_H pin is in
the high-impedance state (hold), regardless of V_M, V_r and the DATA input state.
The LD driving current consists of a switched current I_SW, which is controlled by the DATA input, and I_B, a LD bias
current which is independent of the DATA input state.
Rev.1.00, Sep.22.2003, page 1 of 11