DRV8714-Q1: I use DRV8714 driver a MOS(parameter shows at below picture)，but the rise time of gate isn't meet calculation.

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I test Vdrain（PIN39）,value is 15.9V，and I test Vsh1，the value is 16.3V（PIN23）. SH1 is set to HiZ mode.

Why Vdrain ≠Vsh1？

Hey Ling,

62mA is the maximum drive source/sink current that DRV8714-Q1 can provide, so that is the right setting for max time.  

Do you have Propagation Delay Reduction (PDR) turned on, via EN_PDR_x register setting? See 8.3.4.4 in the datasheet.  This can result in overall much faster rise/fall times.

You could also try Closed Loop Slew Time Control (STC) and set it to fastest settings and see if this results in improved switching time.  

You could check using this FAQ equations to make sure the drive supports these FETs:  [FAQ] How to determine which MOSFETs a gate driver can support?  But I'm pretty sure your FETis fine with 9nC Qgd. 

Beyond that you might need to look into using a different model of FET or a different driver - DRV8702-Q1 and DRV8703-Q1 go up to a drive current of 260mA source / 440mA sink for V_VM around 13.5V.  

Best,

Jacob

Thanks for your reply. For my second question, can you give me some comments? thanks~

Hey Ling,

ling xinjie said:

Why Vdrain ≠Vsh1？

For that let me refer with a coworker who is more familiar with this device, give us a day. 

Make sure you have the required external components for this part matching the datasheet.  Do you have an EVM you could test this out with to confirm whether our EVM gives the same performance?  https://www.ti.com/tool/DRV8714S-Q1EVM 

Best,

Jacob

I don‘t have EVM board.

I check my design，which is matching the datasheet description.

Thanks for your comments.

<Normally due to EMI concern, above SH slew could be good range. I am a little curious why you need to boost up slew rate on GHx/GLx more.>

---I want to decrease the Trise/Tfall of MOSFET，aimed at reduce MOSFET's switching losses

<I do not recommend to use Propagation Delay Reduction (PDR) for you>

---Can you give me some comments, why do not you suggest PDR for me? 

Thank you for your explanation, it is very useful.

add another question of DRV8714

I want to know when normal/short/STG/STB occurred the VDS comparator‘s output.Thanks~

<I want to know when normal/short/STG/STB occurred the VDS comparator‘s output.Thanks>

For this question，I just want to know how to set Register to judge short to battery/short to gnd/short each other/normal

Thanks for your reply. It is useful for my question. Next time I will create new post.

For this question I still have some confuse.

For Open Load，PVDD=16V.

I measure VSHx=15.200V and VGHx=15.000V. Why VSHx have 0.8V voltage drop, VGHx have 1V voltage drop?(respect to PVDD)

I measure VSHy=0.517V and VGHy=0.502V. Why VSHy have 0.517V voltage drop, VGHy have 0.502V voltage drop?(respect to GND)