5
KXX-A12040 A
(1) Circuit board surface to mount a mini-spectrometer
The circuit board surface to mount a mini-spectrometer should be inside an optical system that blocks
external light. So, attaching variable resistors, etc. to the back side of the circuit board surface makes it
easier to adjust them.
(2) Circuit board
The mounting holes for equipment in the circuit board should be made slightly larger than the screw
diameter in order to allow making fine adjustments of the photosensitive area position. Additionally, use a
circuit board that will hardly warp due to temperature variations in order to prevent the focus position from
shifting.
(3) Circuit components
Changes in mini-spectrometer temperature will also cause changes in characteristics such as the sensitivity
and dark current. Using circuit components that emit as little heat as possible is recommended to suppress a
temperature rise in the mini-spectrometer. Besides keeping the product away from heat-emitting circuit
components, please take other measures for heat dissipation.
(4) Grounds
To prevent digital circuit section noise from intruding into the analog circuit section through the ground,
isolate the digital section ground from the analog section ground, and use a thicker ground line to lower its
resistance.
(5) Digital signals
The input clock pulse line causes voltage fluctuations, so separate it as far as possible from the video signal
line and voltage supply line. Apply the input clock pulses at the specific timing and voltage to the product
connection terminals on the circuit board. Additionally, extra caution is needed during high-speed operation.
(6) Analog signals
Keep the wiring width and wiring distance between the video output terminal and amplifier as short as
possible. For the product with the active video and dummy video, set the same wiring width and wiring
distance for both the active video and dummy video side signal lines so that they have the same capacitance
as much as possible. To prevent noise intrusion into the output signal, keep the video signal line away from
digital signal lines such as clock lines that are subject to voltage fluctuations, and also make sure that the
video signal lines and digital signal lines do not cross each other on the front or back of the circuit board.
This reduces clock feed-through.
(7) Supply voltage
Fluctuations in mini-spectrometer supply voltage will cause unstable output characteristics. To avoid this, use
a power supply having minimal voltage fluctuations, and ensure that the mini-spectrometer supply voltage is
not affected by external voltage fluctuations. Do not allow voltage fluctuations on the power supply lines
caused by circuit board component operation to change the product supply voltage. Separate the power
supply lines to the product as far away as possible from digital signal lines such as clock lines where the
voltage changes.
