PS8551L4 Chapter Title
R08DS0039EJ0200 Rev.2.00 Page 15 of 17
Sep 06, 2011
(4) Cautions
• Fluxes
Avoid removing the residual flux with freon-based and chlorine-based cleaning solvent.
2. Cautions regarding noise
Be aware that when voltage is applied suddenly between the photocoupler’s input and output at startup, the output
transistor may enter the on state, even if the voltage is within the absolute maximum ratings.
USAGE CAUTIONS
1. This product is weak for static electricity by designed with high-speed integrated circuit so protect against static
electricity when handling.
2. Board designing
(1) By-pass capacitor of more than 0.1
μ
F is used between VCC and GND near device. Also, ensure that the
distance between the leads of the photocoupler and capacitor is no more than 10 mm.
(2) Keep the pattern connected the input (V
IN+, VIN−) and the output (VOUT+, VOUT−), respectively, as short as
possible.
(3) Do not connect any routing to the portion of the frame exposed between the pins on the package of the
photocoupler. If connected, it will affect the photocoupler's internal voltage and the photocoupler will not
operate normally.
(4) Because the maximum frequency of the signal input to the photocoupler must be lower than the allowable
frequency band, be sure to connect an anti-aliasing filter (an RC filter with R = 68 Ω and C = 0.01
μ
F, for
example).
(5) The signals output from the PS8551 include noise elements such as chopping noise and quantization noise
generated internally. Therefore, be sure to restrict the output frequency to the required bandwidth by adding a
low-pass filter function (an RC filter with R =10 kΩ and C = 150 pF, for example) to the operational amplifier
(post amplifier) in the next stage to the PS8551.
3. Avoid storage at a high temperature and high humidity.
