https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2293291#M59166 <P>Hello&nbsp;<a href="https://community.nxp.com/t5/user/viewprofilepage/user-id/258764">@哈哈哈哈哈</a>&nbsp;</P> <P>&nbsp;</P> <DIV> <P>On the SJA1105Q‑EVB, the 3.3 V power enable signal (VREG_EN) is typically controlled through two paths:</P> <OL> <LI>A control signal from the MCU (LPC1788), MCU_VREG_INH.</LI> <LI>A hardware override via the J9 jumper, which can directly force VREG_EN on or off.<BR />When J9 is used, it bypasses the MCU control path.</LI> </OL> <P>&nbsp;</P> <P>Thank you.</P> <P>BR</P> <P>Alice</P> </DIV> Wed, 14 Jan 2026 11:01:05 GMT Alice_Yang 2026-01-14T11:01:05Z https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2292895#M59164 <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="_0-1768356546887.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/372736iE03378F204B9D0AF/image-size/medium?v=v2&amp;px=400" role="button" title="_0-1768356546887.png" alt="_0-1768356546887.png" /></span></P><P><SPAN>Hello, in the SJA1105Q-EVB evaluation board, the 3.3V enable pin VREG_EN can be controlled as shown in the figure. What is the process and principle between the control by the LPC1788FET208 main chip pin MCU_VREG_INH and the control by the J9 jumper?</SPAN></P> Wed, 14 Jan 2026 02:14:03 GMT https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2292895#M59164 哈哈哈哈哈 2026-01-14T02:14:03Z https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2293291#M59166 <P>Hello&nbsp;<a href="https://community.nxp.com/t5/user/viewprofilepage/user-id/258764">@哈哈哈哈哈</a>&nbsp;</P> <P>&nbsp;</P> <DIV> <P>On the SJA1105Q‑EVB, the 3.3 V power enable signal (VREG_EN) is typically controlled through two paths:</P> <OL> <LI>A control signal from the MCU (LPC1788), MCU_VREG_INH.</LI> <LI>A hardware override via the J9 jumper, which can directly force VREG_EN on or off.<BR />When J9 is used, it bypasses the MCU control path.</LI> </OL> <P>&nbsp;</P> <P>Thank you.</P> <P>BR</P> <P>Alice</P> </DIV> Wed, 14 Jan 2026 11:01:05 GMT https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2293291#M59166 Alice_Yang 2026-01-14T11:01:05Z https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2298751#M59236 If J9 pins 1 and 2 are shorted, control comes from the PHY, meaning the MAC will also lose power. How can it be awakened then? Fri, 23 Jan 2026 06:15:16 GMT https://community.nxp.com/t5/LPC-Microcontrollers/SJA1105Q-EVB/m-p/2298751#M59236 哈哈哈哈哈 2026-01-23T06:15:16Z