DS1842A Datasheet, PDF (1/6 Pages) Maxim Integrated Products – 76V, APD, Bias Output Stage with Current Monitoring

19-4994; Rev 0; 10/09
EVAALVUAAILTAIOBNLEKIT
76V, APD, Bias Output Stage with
Current Monitoring
General Description
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 conjunc-
tion 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 shut-
down. The precision voltage-divider network is provid-
ed for precise control of the APD bias voltage. The
device also includes a dual current mirror to monitor
the APD current.
APD Biasing
GPON ONU and OLT
Applications
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
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS1842AN+
-40°C to +85°C 14 TDFN-EP*
DS1842AN+T&R -40°C to +85°C 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
PGND
FBOUT
FBIN
DS1842A
R₁
MIRIN
CURRENT MIRROR
C_BULK
R₂
MIR1
CLAMP
EP GND
CURRENT
LIMIT
MIROUT
MIR2
ROSA
EXTERNAL MONITOR
APD
TIA
MON3
NOTE: SEE THE LAYOUT CONSIDERATIONS SECTION.
________________________________________________________________ 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.