8-bit MicrocontrollersのトピックESD protection problem https://community.nxp.com/t5/8-bit-Microcontrollers/ESD-protection-problem/m-p/731652#M22503 <HTML><HEAD></HEAD><BODY><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="color: black;">mcu: &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8bit &nbsp; &nbsp;MC9S08SC4</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="color: black;">function : &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dc motor control &nbsp; &nbsp; &nbsp;current about 1A</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;">the shell: &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;PCB ground and</STRONG><SPAN><SPAN style="color: black;">&nbsp;</SPAN><STRONG><SPAN style="color: black;">Motor negative&nbsp;</SPAN>connected with the metal casing directly,Half of the shell is &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;metal &nbsp;half plastic</STRONG></SPAN><STRONG style="color: black;">。</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;">phenomenon:</SPAN></STRONG><STRONG style="color: black;">&nbsp; &nbsp;1: &nbsp;when +15kv air dischage at the metal shell,the mcu reset. &nbsp; &nbsp;distance between the discharge &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;point and mcu is about 6cm.</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 2: &nbsp;solder a wire on the metal shell. &nbsp;<SPAN>Hung it above &nbsp;the mcu about 3cm. &nbsp;then +15kv air discharge &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;at the wire,the mcu &nbsp;breakdown.</SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;"></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>breakdown mcu phenomenon: </SPAN></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I use a LDO to supply the mcu power;normally the voltage should be 5v,&nbsp;because of the &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;breakdown mcu,it is 1v.</SPAN></SPAN></STRONG><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>&nbsp; &nbsp; if I replace the old with new one,the LDO voltage &nbsp;return to normal 5v.</SPAN></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">operation procedure:1:bring generator electrode close to the discharge point &nbsp;until 3mm ,then switch on ,arc appears .</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 2:the devece is &nbsp;placed &nbsp;on the horizontal coupling plane&nbsp;directly.</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">help1: &nbsp;operation procedure is correct?</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">help2: &nbsp;layout suggestion to prevent ESD damage to the mcu.</SPAN><SPAN><SPAN style="color: black; background: #F2F2F2;">Especially&nbsp;</SPAN><SPAN>radiated interference.</SPAN><SPAN>the&nbsp;</SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_10,#blng_part_tran_1_10">specific</SPAN></SPAN><SPAN><SPAN>&nbsp;</SPAN></SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_11,#blng_part_tran_1_11">circuit</SPAN></SPAN><SPAN><SPAN>&nbsp;</SPAN></SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_12,#blng_part_tran_1_12">design is &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;much<SPAN>&nbsp;</SPAN>&nbsp;needed for a newcomer.</SPAN></SPAN></SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="border: none windowtext 1.0pt; padding: 0cm; color: black; background: #F2F2F2;">thank you for your read and help!</SPAN></P><P><SPAN style="color: #666666; background-color: rgba(255, 255, 255, 0.8); font-size: 12px;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</SPAN></P></BODY></HTML> Thu, 23 Nov 2017 12:30:27 GMT fanziyu 2017-11-23T12:30:27Z ESD protection problem https://community.nxp.com/t5/8-bit-Microcontrollers/ESD-protection-problem/m-p/731652#M22503 <HTML><HEAD></HEAD><BODY><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="color: black;">mcu: &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8bit &nbsp; &nbsp;MC9S08SC4</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="color: black;">function : &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dc motor control &nbsp; &nbsp; &nbsp;current about 1A</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;">the shell: &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;PCB ground and</STRONG><SPAN><SPAN style="color: black;">&nbsp;</SPAN><STRONG><SPAN style="color: black;">Motor negative&nbsp;</SPAN>connected with the metal casing directly,Half of the shell is &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;metal &nbsp;half plastic</STRONG></SPAN><STRONG style="color: black;">。</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;">phenomenon:</SPAN></STRONG><STRONG style="color: black;">&nbsp; &nbsp;1: &nbsp;when +15kv air dischage at the metal shell,the mcu reset. &nbsp; &nbsp;distance between the discharge &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;point and mcu is about 6cm.</STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 2: &nbsp;solder a wire on the metal shell. &nbsp;<SPAN>Hung it above &nbsp;the mcu about 3cm. &nbsp;then +15kv air discharge &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;at the wire,the mcu &nbsp;breakdown.</SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); : ; color: black; font-size: 12px;"></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>breakdown mcu phenomenon: </SPAN></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I use a LDO to supply the mcu power;normally the voltage should be 5v,&nbsp;because of the &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;breakdown mcu,it is 1v.</SPAN></SPAN></STRONG><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"><SPAN>&nbsp; &nbsp; if I replace the old with new one,the LDO voltage &nbsp;return to normal 5v.</SPAN></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><STRONG style="background-color: rgba(255, 255, 255, 0.8); color: #666666; font-size: 12px;"><SPAN style="color: black; background: #EEEEEE;"></SPAN></STRONG></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">operation procedure:1:bring generator electrode close to the discharge point &nbsp;until 3mm ,then switch on ,arc appears .</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 2:the devece is &nbsp;placed &nbsp;on the horizontal coupling plane&nbsp;directly.</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">help1: &nbsp;operation procedure is correct?</SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="color: black;">help2: &nbsp;layout suggestion to prevent ESD damage to the mcu.</SPAN><SPAN><SPAN style="color: black; background: #F2F2F2;">Especially&nbsp;</SPAN><SPAN>radiated interference.</SPAN><SPAN>the&nbsp;</SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_10,#blng_part_tran_1_10">specific</SPAN></SPAN><SPAN><SPAN>&nbsp;</SPAN></SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_11,#blng_part_tran_1_11">circuit</SPAN></SPAN><SPAN><SPAN>&nbsp;</SPAN></SPAN><SPAN style="border: none windowtext 1.0pt; padding: 0cm;"><SPAN data-aligning="#blng_part_src_1_12,#blng_part_tran_1_12">design is &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;much<SPAN>&nbsp;</SPAN>&nbsp;needed for a newcomer.</SPAN></SPAN></SPAN></P><P style="margin: 0cm; margin-bottom: .0001pt;"><SPAN style="border: none windowtext 1.0pt; padding: 0cm; color: black; background: #F2F2F2;">thank you for your read and help!</SPAN></P><P><SPAN style="color: #666666; background-color: rgba(255, 255, 255, 0.8); font-size: 12px;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</SPAN></P></BODY></HTML> Thu, 23 Nov 2017 12:30:27 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/ESD-protection-problem/m-p/731652#M22503 fanziyu 2017-11-23T12:30:27Z