DS1842_11 Datasheet, PDF (1/7 Pages) Maxim Integrated Products – 76V, APD, Bias Output Stage with Current Monitoring

19-4557; Rev 1; 3/11
76V, APD, Bias Output Stage with
Current Monitoring
General Description
The DS1842 integrates the discrete high-voltage com-
ponents 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 cur-
rent through the APD and also features an external
shutdown. The device also includes a dual current mir-
ror to monitor the APD current.
Applications
APD Biasing
GPON Optical Network Unit and Optical Line
Transmission
Pin Configuration appears at end of data sheet.
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
♦ Multiple External Filtering Options
♦ 3mm x 3mm, 14-Pin TDFN Package with Exposed Pad
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS1842N+
DS1842N+T&R
-40°C to +85°C
-40°C to +85°C
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
SW
FB
C_{COMP RCOMP}
COMP
D2
DS1875
LX
GATE
DS1842
MIRIN
C_BULK
GND
CURRENT MIRROR
MIR1
CLAMP
CURRENT
LIMIT
MIROUT
MIR2
ROSA
APD
TIA
EXTERNAL MONITOR
MON3
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.