ZHCSIU5A October 2018 – December 2018 DAC43608 , DAC53608
PRODUCTION DATA.
DAC 用于通过单位增益缓冲器设置 MOSFET 的拉电流,如Figure 64 所示。LED 连接在电源和 MOSFET 的漏极之间。该配置允许 DAC 控制或设置流过 LED 的电流量。DAC 后面的缓冲器可控制反馈环路内 MOSFET 的栅极-源极电压,从而补偿由于 MOSFET 温度、电流和老化引起的这种下降和相应漂移。流过 LED 并由 DAC 设置的电流可以用Equation 2 计算得出。为了在 0 – 5V DAC 输出范围内产生 0 – 20mA 电流,需要 250Ω 的 RSET。
下面给出了开始使用 LED 偏置应用所需的伪代码。
//SYNTAX: WRITE <REGISTER NAME(Hex Code)>, <DATA>
//Power-up the device and channels
WRITE DEVICE_CONFIG(0x01), 0x0000
//Program mid code (or the desired voltage) on all channels
WRITE DACA_DATA(0x08), 0x07FC //10-bit MSB aligned
WRITE DACB_DATA(0x09), 0x07FC //10-bit MSB aligned
WRITE DACC_DATA(0x0A), 0x07FC //10-bit MSB aligned
WRITE DACD_DATA(0x0B), 0x07FC //10-bit MSB aligned
WRITE DACE_DATA(0x0C), 0x07FC //10-bit MSB aligned
WRITE DACF_DATA(0x0D), 0x07FC //10-bit MSB aligned
WRITE DACG_DATA(0x0E), 0x07FC //10-bit MSB aligned
WRITE DACH_DATA(0x0F), 0x07FC //10-bit MSB aligned