Basic description

The DS1842A is a APD Bias Output Stage and Fast Current Monitor on a Single Chip. It integrates the discrete high-voltage components necessary for avalanche photodiode (APD) bias and monitor applications. A switch FET and precision voltage-divider network are used in conjunction with an external DC-DC controller to create a boost DC-DC converter. A current clamp limits current through the APD and also features an external shutdown. The precision voltage-divider network is provided for precise control of the APD bias voltage. The device also includes a dual current mirror to monitor the APD current.

Key Features

• 76V Maximum Boost Voltage
• Switch FET
• Current Monitor with a Wide 1µA to 2mA Range, Fast 50ns Time Constant, and 10:1 and 5:1 Ratio
• 2mA Current Clamp with External Shutdown
• Precision Voltage Feedback
• Multiple External Filtering Options
• 3mm x 3mm, 14-Pin TDFN Package with Exposed Pad

Applications/Uses

• APD Biasing
• GPON ONU and OLT

DS1842A