Hello,
Please answer following questions from customer.
Q1: DRVOFF and GHS, SHS behavior
Customer observed VHS, GHSx and SHSx waveform when DRVOFF=High and results are follows.
(VS and VHS is different power supply and VS is always on following waveform.)
Waveform-1:
EN=High, B_EN=High, RSTN=High
Q1-1:
Please explain the reason why SHSx rise to same voltage with VHS and also GHSx rise to same voltage with VHS.
Waveform-2
EN=Low, B_EN=High, RSTN=High
Q1-2:
Please explain the reason why SHSx and GHSx doesn’t rise and zero voltage comparison with Wveform-1.
Q1-3:
Please confirm following my understanding of Passive pull-down, Semi-Active pull-down and Active pull-down is correct or not.
<Passive pull-down>
GHSx and SHSx is connected using 500k ohm resistor for high-said and GLSx and SLSx is connected using 500k ohm resistor for low-said
<Active pull-down>
Driver is enabled and driving Low for low-side and high-side.
<Semi-Active pull-down>
Datasheet explain as follows about Semi-Active pull-down
In addition a semi-active pulldown circuit is reducing the gate impedance at a typical voltage of 2 V to about 7 kΩ.
Please advise following figure of Semi-Active pull-down is correct or not
If it is not correct please correct figure of Semi-Active pull-down image.
[View:/cfs-file/__key/communityserver-discussions-components-files/38/No.63_5F00_Semi_2D00_Active_5F00_pull_2D00_down.pptx:1230:0]
Q2:
Please confirm following my understanding is correct.
Customer tried DRVOFF goes High while IHSx and ILSx is toggled form MCU and VDS error is observed reading STAT0 register.
So VDS error detection works while DRVOFF=High.
Q3:
Customer tried DRVOFF goes High while IHSx and ILSx is toggled form MCU and VDS error should be observed reading STAT0 register like Q3, but no VDS error is observed when Boost undervoltage error is exist in STAT1 register (Actually Boost voltage recovered normal and only Boost UV error flag is not cleared.)
Please answer the reason of no VDS error of above case, Reson-1 or Reason-2 or other.
<Reason-1>
There are priority between error flag and another error flags are masked until existing error flag is cleared.
In case of this reason is correct, please let me known the priority of each error and name of error flag which will masked when xx error flag is exist.
<Reason-2>
When Active pull-down is occurred by error detection, VDS error detection is masked until Active pull-down is canceled by error flag is cleared.
Best Regards.