RX62T R5F562T7DDFP (100 pin) unstable duty cycle on pin 53

Hi all,

I'm having a problem with a RX62T on an inverter board to drive a 3 IGBT's-IPM in order to run a 3 phase compressor from a split unit air conditioner. 2 of the Hi-outputs have a stable 82µs pulse, driving the IPM, but the 3rd Hi-output (pin 53 RX62T) starts up with 82µs and goes to almost DC and forces the IPM in to protection mode because of over current. Is this a fault in the RX62T or is it to be solved with programming and what is the best and most economical solution considering the support of recycle ? I appreciate your input.

  • Need more information. What do you mean exactly by "almost DC"? Does it still switch the full logic levels but the timing is wrong, or is the output voltage not switching to valid logic levels?

    If it is a timing problem then that indicates software.
    If it is a logic level voltage problem then that indicates a circuit problem in your board is overloading the RX62T output pin, or you have a damaged part.
  • In reply to Gerald:

    Thank you Gerald for showing interest to a solution to this matter. The voltage level is stable but the cutoff cycle drops from about 82µs to 5µs or less on pin 53 while the driving cycle goes from 82µs to 159µs or more and forces the inverter power module (IPM) into protection. The other 2 outputs are stable with a cutoff period of 82µs and a drive period of 82µs. What can be the cause and is there a suggestion or a link to program this faulty pin or is there an external input that can affect this pin ?

  • In reply to TTT-Leaders:

    The terminology you are using suggests that you are unfamiliar with the RX62T microcontroller.

    Has the board worked previously?
    Are you a developer of the board or a user of it?
    If you are a developer, do you have access to the software source code?
    If you are a user, then you must seek assistance from the board designer/manufacturer.
  • In reply to Gerald:

    The board has worked before and as a "recycle" promoter and technician I'm interested in repairing the board. I was hoping to get guidance on this platform on how to access the chip and edit that pin output with help of the right tools, documentation and information. What software (Windows 8) do I need to access the chip via I2 bus ?
  • In reply to TTT-Leaders:

    You can try out Renesas' e2studio development tool for free, which is an eclipse based IDE that includes code development and debugging features. There are also flash programming utilities that can be evaluated for free.
    However you will also need an 'emulator' to interface to the MCU, and those must be purchased. The board will not likely have the connector that matches the Renesas emulator so you would need to make an adapter. In addition, you will need the original source code for the software presently embedded in the device to be able to make modifications. The manufacturer may have locked access to the flash memory so that external debug tools cannot read the code out without a security code. Unauthorized attempts to access the flash memory can result in erasure as a security feature.

    So it is very unlikely that you can access the device to accomplish what you want to do without support from the board manufacturer.
  • Thank you again for your input and I will certainly follow your advice and share my progress if any.
  • In reply to TTT-Leaders:

    TTT-Leaders,

    How is your project progressing?
    Have you successfully programmed your board?

    Mike Clements
    RenesasRulz Moderator
  • In reply to Mike Clements:

    Thank you for showing interest. It has been stuck for a while. I need to purchase the emulator. Which one would you recommend for the RX62T ?
  • In reply to TTT-Leaders:

    This thread will be archived due to inactivity.

    Mike Clements
    RenesasRulx Moderator