Turn-off delay is influenced by load conditions. Systems applications well below the specified output loading may require timing considerations for some designs, i.e., multiplexed displays or when used in combination with sink drivers in a totem pole configuration.All unused inputs must be connected to ground. Pulldown resistors ([ch8776] 10 k[ch937]) are recommended for inputs that are allowed to float while power is being applied to VS.
The UDN2981A will source enough current for this LED matrix, but the chip is quite SLOW. If you intend to do fast PWM, you'll see ghost images. The information from row N will 'bleed' to N-1, N-2 etc. You can see this effect in my avatar's icon.