DS3920_1112 Datasheet, PDF (1/7 Pages) Maxim Integrated Products – Fast Current Mirror

19-5797; Rev 2; 12/11
DS3920
Fast Current Mirror
General Description
The DS3920 precision current mirror is designed for ava-
lanche photodiode (APD) and PIN photodiode biasing
and monitoring applications. The device offers a current
clamp to limit current through the APD and a current mir-
ror output that produces a signal proportional (5:1) to the
APD current. A diode is also provided to limit the voltage
at the current mirror output.
The device accepts a +2.97V to +76V current mirror
supply voltage. Internal current limiting (4.4mA or 20mA,
typ) protects the monitored device from a short circuit to
ground. The provided internal clamp diode protects the
current mirror output from overvoltage. Additionally, the
device features thermal shutdown if the die temperature
reaches +150NC.
The device is available in a 6-pin SOT23 package, and
operates over the -40NC to +85NC extended temperature
range.
Features
S Wide Voltage Input Range: 2.97V to 76V
S Current Monitor
 Wide 250nA to 2mA Range
 5:1 Mirror Ratio
 Fast 50ns Time Constant
S Current Clamp (4.4mA or 20mA, typ)
S Voltage Clamp Protects Subsequent Output Circuitry
S 6-Pin SOT23 (MAX4007 Compatible)
Applications
Avalanche Photodiode (APD) Biasing
PIN Photodiode Monitoring
GEPON, GPON, 10GEPON, XGPON: ONU and OLT
Ordering Information appears at end of data sheet.
Typical Application Circuit
3.3V
DIODE
CURRENT
MONITOR
IMIROUT
MIRIN
IMIROUT/5
APD BIAS
RFILTER
100Ω–1000Ω
CFILTER
0.1μF
THERMAL
SHUTDOWN
GND
CURRENT
LIMIT
MIROUT
DS3920
R_AGC
499Ω
ROSA
APD
TIA
MIR ^IMIROUT^/5
VOUT
R_OUT
1kΩ–5kΩ
For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/DS3920.related
����������������������������������������������������������������� 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.