The traces that carry current from the LED cathodes to the OUTx pins must be wide enough to support the default current (up to 120 mA).
The SDI, CLK, LE(ED1), OE(ED2), and SDO pins should be connected to the microcontroller. There are several ways to achieve this, including the following methods:
The thermal pad in the PWP package should be connected to the ground plane through thermal relief vias. This layout technique will improve the thermal performance of the package.