12-Bit High Output Current Source
ADN8810
FEATURES
High precision 12-bit current source
FUNCTIONAL BLOCK DIAGRAM
5V
5V
3.3V
Low noise
Long term stability
ENCOMP DVDD AVDD
RESET
PVDD
Current output from 0 mA to 300 mA
Output fault indication
Low drift
Programmable maximum current
24-lead 4 mm × 4 mm leadframe chip scale package
3-wire serial interface
RESET
4.096V
FB
VREF
CS
R
SN
1.6V
IOUT
ADN8810
SERIAL
INTERFACE
SCLK
SDI
R
SN
1.6V
D1
R
SN
ADDRESS
ADDR0-2
FAULT
3
AVSS
SB
DGND
DVSS
APPLICATIONS
SB
FAULT
Tunable laser current source
Programmable high output current source
Automatic test equipment
INDICATION
Figure 1.
GENERAL DESCRIPTION
The ADN8810 is a 12-bit current source with an adjustable
full-scale output current of up to 300 mA. The full-scale out-
put current is set with two external sense resistors. The output
compliance voltage is 2.5 V, even at output currents up to
300 mA.
The device is particularly suited for tunable laser control and
can drive tunable laser front mirror, back mirror, phase, gain,
and amplification sections. A host CPU or microcontroller
controls the operation of the ADN8810 over a 3-wire SPI®
interface. The 3-bit address allows up to eight devices to be
independently controlled while attached to the same SPI bus.
The ADN8810 is guaranteed with ꢀ ꢁSB INꢁ and 0.ꢂ5 ꢁSB
DNꢁ. Noise and digital feedthrough are kept low to ensure low
jitter operation for laser diode applications. Full-scale and
scaled output currents are given in Equations 1 and 2,
respectively.
VREF
10× RSN
IFS
≈
(1)
(2)
+ 0.1⎟⎞⎟
⎛
VREF
1
⎜ RSN
IOUT = Code ×
×
×
ꢀ096 RSN ⎝⎜ 15k
⎠
Rev. 0
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