Design Article
MCU-based LED drivers inspire designs
Alex Zaretsky, Renesas
12/3/2012 11:56 AM EST
RL78/I1A MCU ASSP for lighting applications
RL78/I1A is an ASSP member of Renesas’ latest RL78 series of microcontrollers which combines the best features of its previous industry standard microcontroller cores, the 78K0 and the R8C, and offers higher computing performance.
This new 16-bit microcontroller generation boasts the lowest power consumption in its class in the world. It offers two different on-chip flash ROM configurations, and - depending upon the ambient temperature - can optionally operate at 24 or 32MHz. The MCU is available in 20, 30, 32, and 38 pin plastic (TSSOP, SSOP, and VQFN) package variants.
The RL78/I1A integrates all the necessary functions and resources required for a typical LED lighting application on board and it thus represents a single chip low power, low cost solution without sacrificing efficiency.
Lighting application specific functions like DALI (Digital Addressable Lighting Interface), DMX512 (Digital MultipleX), RDM (Remote Device Management), ZigBee, and Power Line Communications (PLC) are integrated on-chip. The on-chip extended DALI transceivers are augmented by other major standard interfaces like UART, SPI, and I2C.
The integrated on-chip functionality and intelligence reduces the need for additional external components (BoM). The reduced BoM in turn simplifies the parts procurement, system tests, production process, and increases the overall system reliability; it is thus a compelling argument for many LED drivers and lighting ballast designs where space is at a premium.

Figure 1: Block diagram of the RL78/I1A MCU
RL78/I1A is an ASSP member of Renesas’ latest RL78 series of microcontrollers which combines the best features of its previous industry standard microcontroller cores, the 78K0 and the R8C, and offers higher computing performance.
This new 16-bit microcontroller generation boasts the lowest power consumption in its class in the world. It offers two different on-chip flash ROM configurations, and - depending upon the ambient temperature - can optionally operate at 24 or 32MHz. The MCU is available in 20, 30, 32, and 38 pin plastic (TSSOP, SSOP, and VQFN) package variants.
The RL78/I1A integrates all the necessary functions and resources required for a typical LED lighting application on board and it thus represents a single chip low power, low cost solution without sacrificing efficiency.
Lighting application specific functions like DALI (Digital Addressable Lighting Interface), DMX512 (Digital MultipleX), RDM (Remote Device Management), ZigBee, and Power Line Communications (PLC) are integrated on-chip. The on-chip extended DALI transceivers are augmented by other major standard interfaces like UART, SPI, and I2C.
The integrated on-chip functionality and intelligence reduces the need for additional external components (BoM). The reduced BoM in turn simplifies the parts procurement, system tests, production process, and increases the overall system reliability; it is thus a compelling argument for many LED drivers and lighting ballast designs where space is at a premium.

Figure 1: Block diagram of the RL78/I1A MCU
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anne-francoise.pele
4/12/2013 8:57 AM EDT
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