Do i need a LED driver to drive 32 mosfets?
Here are examples of 500mA constant current LED drivers. Looks like most need a PWM input to control dimming. https://www.digikey.com/products/en/integrated-circuits-ics/pmic-led-drivers/745?FV=7b80001%2C1f140000%2Cffe002e9&amp;quantity=0&amp;ColumnSort=1000011&amp;page=1&amp;stock=1&amp;k=led+driver&amp;pageSize=25&amp;pkeyword=led+driver  If you paired these with SX1509 to create the PWM signals, that might do what you want  https://www.digikey.com/product-detail/en/semtech-corporation/SX1509BIULTRT/SX1509BIULCT-ND/2295548