DS1842A

19-4994; Rev 0; 10/09 KIT ATION EVALU LE B A IL A AV 76V, APD, Bias Output Stage with Current Monitoring General Description 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 DS1842A The DS1842A 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. Applications APD Biasing GPON ONU and OLT PART DS1842AN+ DS1842AN+T&R Ordering Information TEMP RANGE -40°C to +85°C -40°C to +85°C PIN-PACKAGE 14 TDFN-EP* 14 TDFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. *EP = Exposed pad. Typical Application Circuit 3.3V LX FBIN CBULK DS1842A SW GATE PGND FBOUT R2 CCOMP R COMP COMP D2 CLAMP CURRENT LIMIT MIROUT ROSA MIR1 R1 MIRIN www.DataSheet4U.com CURRENT MIRROR FB MIR2 EXTERNAL MONITOR EP GND DS1875 APD TIA MON3 NOTE: SEE THE LAYOUT CON...