TI中文支持网F28377数据手册对上电顺序的说明：
The voltage on VDDIO should be greater than or equal to the voltage on VDD during power up. Before
powering the device, no voltage larger than 0.3 V above VDDIO should be applied to any digital pin, and no
voltage larger than 0.3 V above VDDA should be applied to any analog pin. The internal power-on-reset
circuit will ensure glitchless IOs during power up.
其中VDDIO是3.3V，VDD是1.2V
它的意思是需要3.3V先上电，1.2V后上电，我可以像下图那样用3.3V去产生1.2V吗？
mangui zhang：
你好 一般控制器都是要求IO电压优先于内核电压上电
建议你最好参考TI 的EVM板设计 或者使用TI的电源芯片
1117不知道电流能到多少 能不能满足内核电压要求？
你这种方案会产生延时 不知道能不能满足要求
F28377数据手册对上电顺序的说明：
The voltage on VDDIO should be greater than or equal to the voltage on VDD during power up. Before
powering the device, no voltage larger than 0.3 V above VDDIO should be applied to any digital pin, and no
voltage larger than 0.3 V above VDDA should be applied to any analog pin. The internal power-on-reset
circuit will ensure glitchless IOs during power up.
其中VDDIO是3.3V，VDD是1.2V
它的意思是需要3.3V先上电，1.2V后上电，我可以像下图那样用3.3V去产生1.2V吗？
wuxian：
回复 mangui zhang:
谢谢你的回答，1117是800mA，能够满足芯片的要求。只是上电时序能否满足要求就不知道了，官方的用的DC-DC感觉太复杂了，想用一个简单点的，常用的芯片来做。
F28377数据手册对上电顺序的说明：
The voltage on VDDIO should be greater than or equal to the voltage on VDD during power up. Before
powering the device, no voltage larger than 0.3 V above VDDIO should be applied to any digital pin, and no
voltage larger than 0.3 V above VDDA should be applied to any analog pin. The internal power-on-reset
circuit will ensure glitchless IOs during power up.
其中VDDIO是3.3V，VDD是1.2V
它的意思是需要3.3V先上电，1.2V后上电，我可以像下图那样用3.3V去产生1.2V吗？
囧：
回复 wuxian:
F28377没有明确的上电时序要求，但是建议按照controlcard来做
F28377数据手册对上电顺序的说明：
The voltage on VDDIO should be greater than or equal to the voltage on VDD during power up. Before
powering the device, no voltage larger than 0.3 V above VDDIO should be applied to any digital pin, and no
voltage larger than 0.3 V above VDDA should be applied to any analog pin. The internal power-on-reset
circuit will ensure glitchless IOs during power up.
其中VDDIO是3.3V，VDD是1.2V
它的意思是需要3.3V先上电，1.2V后上电，我可以像下图那样用3.3V去产生1.2V吗？
wuxian：
后来将两种电源方案都设计上了，经过测试，直接用lll7-1.2是可以的
