LED 101 / Hardware
LED drivers and scan rate
Driver chips set current and PWM for each lamp. Scan rate is how those drivers share time across rows of the module.
LED drivers are the chips on the module that feed current to the lamps. LEDs want regulated current. The drivers also dim with pulse-width modulation: the lamp flips on and off fast enough that your eye sees a brightness level. That PWM depth is part of what limits grayscale and colour smoothness.
Scan rate is separate from refresh rate. A 1/16 scan means each row is driven one-sixteenth of the time in the multiplex cycle. Lower scan fractions (for example 1/8 versus 1/32) often mean each row is on longer per cycle, which can ease peak current and heat for a given brightness. Higher scan counts are a way to drive more LEDs with fewer driver channels. The right balance is a product design choice, not something you “improve” by adding LEDs.
When a wall flickers on camera, looks uneven, or cannot hold a clean gradient, drivers and scan design are on the shortlist next to the receive card and the processor.