UCC25600 questions about datasheet

Q1) In page 1, there is a following description, but not mentioned in Electrical Characteristics parts in the datasheet.
“ Integrated Gate Driver With 0.4-A Source and 0.8- A Sink Capability”
Is this guaranteed specification?

No. This is typical numbers. We can't measure the peak current during the test. The gate driver is tested based on the on resistance and the rise fall time as shown in datasheet page 6 GATE DRIVE section

Q2) In Table 1, DT port explanation, it says 
“To prevent shoot through when this pin is accidentally shorted to ground, the minimum dead time is set to 120 ns. Any dead time setting less than 120 ns will automatically have 120-ns dead time.”
  Is this 120-ns guaranteed value?
  Can you show min/max value for this period?

I need to check with test engineer and find that out

Q3)Regarding to SS capacitor, 1uF is defined as recommended maximum capacitor.
  In customer's application, longer soft start period will be required and more capacitor is required than 1uF.
- Is 1uF actual maximum capacitor for correct operation?
- Why maximum capacitor is defined as 1uF?

The  recommended maximum SS capacitor is to consider the internal discharge circuit current handling capability. If you need longer soft start time, you can either parallel a resistor with the capacitor to bypass some soft start current or use extra diode and capacitor to make your own soft start and then discharge the big capacitor through other means

Q4) Regarding to “FSW(start)”, is this fixed value and user can not configure this value?

The start up frequency is ~100kHz above your minimum switching frequency setting. It changes with your minimum switching frequency setting

Q5) Regarding to “GATE DRIVE” specification, GD1, GD2 output voltage high is specified as 9V(min) to 11V(max).
  Is this defined under the condition of VCC being between 11V and 18V?

No, it is only for 11V . There is no voltage clamp of this driver.

Q6) “Thermal shutdown threshold” is defined as 160deg(typ), but absolute maximum ratings for Tj is described as 125deg.
  Why thermal shutdown is defined as 160deg which is far above Tj max?

The minimum value for the thermal shut down needs to be above 125 so that we can guarantee the 125

Q7) Customer wants to set switching frequency as 290kHz.
According to equation (18), required IRT will be
                           IRT = 290[kHz]/83[Hz] = 3.493mA
To get IRT of 3.493mA, RT resistance would be,
                     RT resistance = 2.5V/3.493mA = 0.715kohm.
- Is it correct understand?
In this case 0.715kohm is smaller than 1kohm, which is smaller than recommended RT resistance.
- What is the concern when using RT resistance under 1kohm?

There is no concern on RT resistance small. However, the part  enters burst mode operation at 350kHz with minimum value of 300kHz. Operate at 290kHz gives very little room to operate

Besides, the RT is to set up the minimum switching frequency at lowest input voltage and maximum load. The normal operation frequency is demanded by the feedback loop

Q8) What is OC_latch? Could you provide explanation for this?
Would OC_latch be connected to FAULT block in Block Diagram?

When the CS pin goes above 2V typical, IC latches off, You need to recycle VCC to release the latch

Q9) In section 7.3.1, it says "During soft start, the switching frequency is increased."
  With followings, this expression makes the customer bit confusing.
- From Figure 12, switching frequency looks like decreasing during soft start.
- And Start frequency is fixed at 142.5kHz with regardless with RT resistance.
Is this based on the assumption that operating switching frequency is typically higher than 142.5kHz?

As mentioned earlier, the soft start makes the startup frequency about 100kHz above the minimum switching frequency. The soft start pin work this way. The lower the SS pin voltage, the more it increases the switching frequency. At beginning, the SS pin voltage is low, so it increases the frequency a lot. Later, when the SS pin voltage becomes higher, it increase the frequency lower. So it appears the frequency is reducing. In reality, it is just decreasing the extra switching frequency it added

Q2) In Table 1, DT port explanation, it says  

“To prevent shoot through when this pin is accidentally shorted to ground, the minimum dead time is set to 120 ns. Any dead time setting less than 120 ns will automatically have 120-ns dead time.”

 Is this 120-ns guaranteed value?

 Can you show min/max value for this period?

After checking, the 120ns is not a tested value. This value should be based on the design and not a guaranteed value.

Hello Lu-san,