LPC2478 board and current consumption

Introduction

This Technical Note applies to IAR Systems KickStart Kit for NXP Semiconductors’ LPC2478.

Discussion

Debugging with the LPC2478 board fails. For example, the 'J-Link Control Panel' shows a failure for overcurrent in the 'Target Power' tab.

Background

The LCD mounted on one batch of the LPC2478 board use too much power due to increased backlight. This will in turn use too much power for the debug probe to be able to power-up the board.

Solution

Use an external power adapter. Change position of EXT/JLINK jumper to EXT (pin 2-3 closed) in the lower right corner. The power input should be +(9-12V DC) / 6V AC.

Solution by modifying the board

It is also possible to change R22 from 1 Ohm to 2.2 Ohm, picture below. (Note that such a change ends the warranty of the board.)

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