DS3920
Fast Current Mirror
General Description
Features
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.
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)
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.
Applications
Avalanche Photodiode (APD) Biasing
PIN Photodiode Monitoring
GEPON, GPON, 10GEPON, XGPON: ONU and OLT
The device is available in a 6-pin SOT23 package, and
operates over the -40NC to +85NC extended temperature
range.
Ordering Information appears at end of data sheet.
Typical Application Circuit
APD BIAS
R
FILTER
100Ω–1000Ω
3.3V
MIRIN
DIODE
C
FILTER
0.1μF
CURRENT
MONITOR
I
I
/5
MIROUT
MIROUT
THERMAL
SHUTDOWN
I
/5
GND
MIR MIROUT
V
OUT
CURRENT
LIMIT
R
OUT
1kΩ–5kΩ
DS3920
MIROUT
R
AGC
499Ω
ROSA
APD
TIA
For related parts and recommended products to use with this part, refer to: www.maximintegrated.com/DS3920.related
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
19-5797; Rev 2; 12/11