DS1842

19-4557; Rev 0; 4/09 www.DataSheet4U.com 76V, APD, Bias Output Stage with Current Monitoring General Description The DS1842 integrates the discrete high-voltage components necessary for avalanche photodiode (APD) bias and monitor applications. A switch FET is 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 device also includes a dual current mirror to monitor the APD current. ♦ 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 ♦ Multiple External Filtering Options ♦ 3mm x 3mm, 14-Pin TDFN Package with Exposed Pad Features DS1842 Applications APD Biasing GPON Optical Network Unit and Optical Line Transmission Ordering Information PART DS1842N+ DS1842N+T&R TEMP RANGE -40°C to +85°C -40°C to +85°C PIN-PACKAGE 14 TDFN-EP* 14 TDFN-EP* Pin Configuration appears at end of data sheet. +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. *EP = Exposed pad. Typical Application Circuit 3.3V LX DS1842 SW GATE GND FB COMP D2 CLAMP CURRENT LIMIT MIROUT ROSA DS1875 APD TIA MIRIN CBULK CURRENT MIRROR MIR1 CCOMP R COMP MIR2 EXTERNAL MONITOR MON3 ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxi...