Datasheet

AD5382 Data Sheet
Rev. C | Page 36 of 40
OPTICAL ATTENUATORS
Based on its high channel count, high resolution, monotonic
behavior, and high level of integration, the AD5382 is ideally
targeted at optical attenuation applications used in dynamic
gain equalizers, variable optical attenuators (VOA), and optical
add-drop multiplexers (OADM). In these applications, each
wavelength is individually extracted using an arrayed wave
guide; its power is monitored using a photodiode, transimped-
ance amplifier and ADC in a closed-loop control system.
The AD5382 controls the optical attenuator for each wavelength,
ensuring that the power is equalized in all wavelengths before
being multiplexed onto the fiber. This prevents information loss
and saturation from occurring at amplification stages further
along the fiber.
ATTENUATOR
ATTENUATOR
ATTENUATOR
ATTENUATOR
AWG
AWG
FIBREFIBRE
DWDM
OUT
OPTICAL
SWITCH
11
12
1n–
1
1n
DWDM
IN
AD5382,
32-CHANNEL,
14-BIT DAC
N:1 MULTIPLEXER
16-BIT ADCCONTROLLER
TIA/LOG AMP
(AD8304/AD8305)
ADG731
(32:1 MUX)
AD7671
(0V TO 5V, 1MSPS)
PHOTODIODES
ADD
PORTS
DROP
PORTS
03733-044
Figure 43. OADM Using the AD5382 as Part of an Optical Attenuator