A substrate for an LED emitter includes a body with a recess region formed therein. Bonding pads are disposed within the recess region, including LED bonding pads for LEDs and supporting chip bonding pads for one or more semiconductor chips that provide supporting circuitry (e.g., driver and/or controller circuitry) to support operation of the LEDs. External electrical contacts can be disposed outside the recess region. Electrical paths, disposed at least partially within the body of the substrate, connect the external electrical contacts to a first subset of the supporting chip bonding pads and connect a second subset of the supporting chip bonding pads to the plurality of LED bonding pads such that one or more supporting chips connected to the controller pads can be operated to deliver different operating currents to different ones of the LEDs.