https://community.nxp.com/t5/LPC-Microcontrollers/LPC1759FBD80/m-p/1252781#M44445 Hello, I am currently using the LPC1759FBD80 microcontroller to control 24 relays, I wonder if the outputs are on low state or high state at startup, or undetermined, because I do not want to excite the 24 relays at once I risk to burn out since the power is high with a total current of 2.4 Amp. Fri, 26 Mar 2021 10:03:34 GMT AMMOURKENZA1 2021-03-26T10:03:34Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC1759FBD80/m-p/1252781#M44445 Hello, I am currently using the LPC1759FBD80 microcontroller to control 24 relays, I wonder if the outputs are on low state or high state at startup, or undetermined, because I do not want to excite the 24 relays at once I risk to burn out since the power is high with a total current of 2.4 Amp. Fri, 26 Mar 2021 10:03:34 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC1759FBD80/m-p/1252781#M44445 AMMOURKENZA1 2021-03-26T10:03:34Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC1759FBD80/m-p/1253429#M44459 <P>Peripheral in/outputs of basically all Cortex M devices are in a high-impedance state (Z) after startup or reset.</P><P>Peripheral units need to explicitly be enabled to work (power and clock).</P><P>To be safe, I would highly suggest to add pull-up or pull-down resistors to your relais drivers, to ensure startup in a safe state. The value should not interfere with the operation once the GPIO is enabled.</P> Mon, 29 Mar 2021 08:16:00 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC1759FBD80/m-p/1253429#M44459 frank_m 2021-03-29T08:16:00Z