Application Notes on TITLE：EM55S Series Vo can’t connect LED Document Number : Date of Issue : Issue Version : Supported Chips : Applicable Software : AP-EM55S-0003E 1 March 2002 1.0 All EM5500S Series chips We found that some users connect an LED or Lamp to Vcc at Vo or Vo1 pin or as shown in the figure below: Such connection is dangerous! Because the EM55S Series will enter into Test mode when Vo Pin is at High during Power ON reset. Test mode is only used for factory in-house chip testing purposes. (Refer to the Note on the EM5500S Spec, pages 4~7) Please do NOT use the above method of application circuit. The function cannot perform emulation on the EM55S kernel chip. 1 of 1