MSL2164:16串LED驱动器设计指南详解（独家）

The processed GSC signal (the signal after being frequencymultiplied or divided, from either internally or externallygenerated signal at GSC) precisely sets each string’s phasedelay so that it is synchronized to its physical position onthe LCD panel, relative to the beginning, middle or endof the video frame. There are four different types of PWMmodulation modes, each defined by the part of the “on”time or off-time set by the PHDLYn[11:0] register (part of theSTRnSET register). The modes are “forward,” “center,” “reverse,” and “inverse”. All four modes use the PHDLYnregister to set the defined edge, and PWMn[11:0] to setthe “on” time as a number of processed GSC pulses.

Thefour different modes and register definitions are illustratedin the figure below, showing the current waveforms. Thedelay for string 0 is held at 0, and the PWM width is thesame for both strings and all the modes. Datan in thefigure refers to both the dimming data and the phase delaydata presented for the nth frame. For “forward” modePHDLYn specifies the number of processed GSC cyclesafter the processed PHI edge that the string “on” timebegins and the PWMn register specifies the “on” time.

In this mode the falling edge varies with the “on” timewidth programmed in the PWMn register, with the risingedge held constant. In “center” mode, the delay is setfrom the processed PHI edge to the center of the PWM onpulse with width set by the PWMn register. Both the risingand falling edge vary based on the PWMn with the centerheld constant within a processed GSC cycle. In “reverse”mode, the PHDLYn sets the delay from the next frame’sprocessed PHI edge to the falling edge of the PWM “on”time and the PWMn register determines the PWM “on”time. Therefore the rising edge varies with PWMn and thefalling edge is held constant. In “inverse” mode, the delayis set from the next frames PHI edge backwards to thefalling edge of the “on” time. The rising edge varies withthe PWMn register, while the falling edge is held constant.

相关阅读：

最实用的LED驱动设计的18个经典案例分析，原理，电路，方案，验证，一网打尽

推荐阅读：

1.MSL2164:16串LED驱动器应用案例精讲

摘 要：这些LED驱动器可与爱特梅尔tinyAVR®、megaAVR和AVR XMEGA等AVR®微控制器(MCU) 无缝集成。微控制器处理定时和调光指令，将数据发送给MSL2164和MSL2166器件。 AVR器件与固件提供优化整个背光设计的总体解决方案，提供相比竞争解决方案更卓越的性能。