The heatsink solution provided by optical module manufacturers (for example, a heat spreader or planar copper-fin heatsink) is physically sized to achieve a target brightness specification, given the constraints of the maximum heat load on the DMD (see datasheets), the maximum available illumination drive current, and the minimum efficiency of the illumination source. Based upon the heatsink solution provided by the OMM, a mechanical systems engineer can determine the appropriate amount of passive or active cooling (for example, a fan) required to keep the DMD and illumination source within their respective recommended operating temperature ranges. Using an active cooling solution can add power and audible noise, but can also dissipate more heat.

Keep in mind that if a particular application does not require the maximum brightness for which an optical module was designed, then the system electronics can be programmed to run the optical module at a lower power and brightness level. For such applications, there is also an opportunity to reduce the product size by reducing the air flow and/or working with the optical module manufacture to reduce the heatsink size.