数模转换器DAC8718 8734电源上电顺序问题
之前有用DAC8718,电源上电顺序使用了继电器进行控制,这回设计要求体积小,可能要拿掉继电器,问一下如果数字电和模拟电同时上电下电可不可以?
手册并没有给出上电的时序规定.
不过由于控制电路属于数字部分, 最后让模拟电源不晚于数字电源达到稳定
一般有上电时序要求的在datasheet中都会给出,如果没有的话,就没问题,像DAC8718,如果想通过AVDD来产生DVDD,IOVDD,应该也是没问题的。
官方的评估板在其使用手册中提到了需要注意上电顺序,而且是数字电先上
按照这个顺序进行上电
For proper power-on initialization of the device, IOVDD and the digital pins must be applied before or at the same
time as DVDD. If possible, it is preferred that IOVDD and DVDD can be connected together in order to simplify the
supply sequencing requirements. Pull-up resistors should go to either supply. AVDD should be applied after the
digital supplies (IOVDD and DVDD) and digital initialization pins (LDAC, CLR, RST, CS, and RSTSEL). AVSS can
be applied at the same time as or after AVDD. The REF-x pins must be applied last.