Expected voltages for U5 chip

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  • #37712
    skullknightx
    Participant

    I am tshooting an init-2 error – Given this LDO voltage regulators (u5) proximity to power intake, i wanted to take some test measurements to make sure that it was functioning properly. on the input side i am am measuring 4.8 volts – on the output side of the circuit i am seeing something like 3.4 or so. I haven’t been able to find out what should be expected at each side , and dont want to pop out a chip simply based on a hunch. Any help would be greatly appreciated.

    #37715
    skullknightx
    Participant

    UPDATE: also performed check on U6 input is 4.9 and output is 1.3. per the data sheet this seems within tolerance

    #37716
    skullknightx
    Participant

    Finally on to something here i believe- per the code init error – 2 is related to the operation of U17. Input check for u17 yielded 1.3 volts. operating range per the data sheet should be within the 2.7 to 5 v range. Next steps are to examine trace layouts for u17 and walk back the power input.

    // IT6613 officially supports only 100kHz, but 400kHz seems to work
        I2C_init(I2CA_BASE,ALT_CPU_FREQ,400000);
        //I2C_init(I2C_OPENCORES_1_BASE,ALT_CPU_FREQ,400000);
    
        /* Initialize the character display */
        lcd_init();
    
        if (!ths_init()) {
            printf("Error: could not read from THS7353\n");
            return -2;
    #37719
    skullknightx
    Participant

    may very well have posted my way through this one. I actually think I caught the trouble early on but simply had to walk through it all to get the answer. I have a high degree of confidence that my U6 chip is at fault here. this chip appears to feed u17 – per the data sheet for u17 it needs 2.7 to 5 volts for voltage input which means the 1.3 worth of output on u6 is clearly not sufficient.

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