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UCD3138: About UCD3138 Application problem

Part Number: UCD3138

Hi  Friend:

      I have some problem about UCD3138 application; can you help resolve? Thank you

1、Which I/O ports correspond to software program update and download;

2、If I use multiple modules, how to design and wiring;

3、Whether the dead time of each PWM channel can be adjusted;

4、The input voltage we designed is generally between 200-400v and the output is 14V/28V. Do you have any data or samples in this regard for our reference?

  • Most commonly the PMBus ports, specifically PMBUS_CLK and PMBUS_DATA are used for initial download.  We also support, and some customer use, the JTAG pins, which are TCK, TMS, TDI, and TDO.  For software update, you can use the pins above, as well as the UART pins, the SPI pins, the I2C pins, and, if you want to be clever, pretty much any GPIO pins.

    The difference is that a a blank UCD has ROM support for download via PMBus pins, and hardware support for download via JTAG pins.  For firmware updata, there is capability for a boot flash program, so whatever download method you are clever enough to program can be used for update once you download the boot flash program with the two inherently supported interfaces.  

    The interconnection for multiple modules depends on which modules.  To do what you need to do, you probably need 2 UCDs, one controlling a PFC, and one controlling a DC/DC supply to drop the high voltage from the PFC down to your desired voltage.  Typically the interface between PFC and DC/DC has:

    Isolated serial interface - 2 lines between a UART on the PFC and a UART on the DC/DC.  This can carry relatively low speed information back and forth, including commands,. monitoring data, and program updates.  

    1 or more lines for high speed information between the PFC and DC/DC, also isolated.  There seems to always be an AC DROP line from the PFC to the DC/DC, since this needs to be quicker than can easily be supported by the UART.  

    Of course, there's also always the high voltage signal from the PFC to the DC/DC.  Sometimes there's also a little bias supply to provide power to limited parts of the DC/DC.  

    Certainly the dead time for each PFC channel can be adjusted.  The UCD3138 family members have very sophisticated DPWM logic that was designed to support many topologies, and that we have stretched to support more.  We can do everything from a simple buck to a phase shifted full bridge/LLC combination.  

    I suggest reading the device data sheets, and especially the UCD3138 Technical Reference Manual at:

    http://www.ti.com/lit/ug/sniu028a/sniu028a.pdf