24 Channel USB Connected LED Controller, upto 1A per Channel

Step 3 Resistors and Disc Capacitors

Disc Capacitors:

- The bigger one is the 220nF and is C1 on the layout.

- The two smaller ones are 100nF(0.1uF) and are C4 & C5 on the schematic


Resistors:

- First place the 10kohm resistor, R25, for MCRL pull-up.

- Next are 220 ohm, R1-R24, they limit the current going to the transistor's base, the kit comes with Darlington transistors,  which need very little current to fully saturate(turn on).

- Last are R26 & R27, 22 ohm resistors.(v2 hardware)

Comments

[simmunity]

One detail is that the kit comes with one 100nf cap and that should be soldered as close as possible to the power and ground pins on the chip, not off to the side as recommended. The reason is that this cap prevents power spikes and when mounted far from the power pins, causes the PCB trace wires to become inductors and the effect of the cap to smooth the power is reduced. So lay the cap on the bottom of the board between the two sets of power pins and solder to teh traces there for best effect. Prefereably the kit would ship with two and those would be soldered directly across each power and ground pin set, on the chip but my kits only included one cap.