ADN8820

EDFA and CW Laser Controller Preliminary Technical Data FEATURES Four Operational Modes Including: Constant Laser Current Constant Optical Output Power Constant EDFA Gain Constant Laser Power High Power Efficiency: >90% Three Built-In Photodiode TIAs Adjustable Laser Diode and EDFA Protection Limits Free-run or Synchronous Switching Frequency Modes Adjustable Phase Delay for Synchornous Clock Mode Optional Dithering Built-In Programmable Dither Frequency and Amplitude ADN8820* Output Power (COP), or Constant EDFA Gain (CG). Multiple pump laser applications are easily supported by the ADN8820. Common-cathode-to-ground and common-anode-to-VDD configurations are also supported. The ADN8820 has a high speed closed-loop control, making it suitable for add/drop applications in telecommunication systems. It has a low-current shutdown mode and a soft-start feature to minimize power supply bounce on start-up. Protection circuitry is built into the device. The protection limits are easily adjustable and are used to set maximum output current and voltage, optical output power, EDFA gain, and pump or CW laser power. The output stage consists of a high-efficiency PWM amplifier in parallel with a high-speed linear amplifier. This provides the fastest settling time response along with the lowest power and heat dissipation. A pair of external MOSFETs on the PWM amplifier provide output currents of up to 5A. Three low-bias current TIAs are built-in. These allow amplification for the laser ba...