Hello All,
A costumer was looking to use 30 TLC59711 units in cascade for an HMI interface.
The original design had VLED=Vcc=Vreg=3.3, after checking the used LED forward drop at 10mA, the supplier estimate the maximum value at 3.5V.
and for that I have changed the Vled tp 5V with 4.9kOhm Ref resistor for approximately 10mA current limit and left the Vcc=Vreg=3.3V to keep the voltage compatibility with the MCU.
My questions are as follow :
- is there any recommendation for the coupling capacitors ?
- Should I add some series resistors to the SDI & SCK pins ( 22Ohm)
- as for the last of the cascade, any recommendation in particular for the SDO/SCKO pins ?
Thank you in advance for the support