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 Performance features |
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 System construction： |
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| Logic level: |
Logic level includes PWM input signal level,mode select level ,reset signal and fault signal input/output level.
PWM signal level:
Due to all kinds of interference ,PSHI driver set a standard level of 15V(adjusted from factory) anti-jamming environment. Especially the connection lead (L>50cm)between the external control circuit and the driver(anti-jamming ability needed to be considered) is not short enough.And you should convert the control signal before connecting the driver if you don't choose the 15V .Signal conversion circuit such as CD40109BMS (four-channel level converter) ,CD4049(six-channel level converter)and so on.
Mode select level,reset signal and fault signal input level:
All the logic level of driver operate below 15V ,the logic level of driver is 15V ,upset threshold is 8V. So 15V is very suitable as logic signal.
The fault signal output level are open circuit output, and it should be 15V logic level if as logic output. |
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| Working mode select: |
| PSHI above two-channels have a model selection circuit to selcet indepedent mode or half-bridge interlock mode by pin(jumper). |
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| Interlock dead time: |
"Interlock" circuit prevents the two IGBTs of the half bridge to switch on at the same time, and there is a dead time between the top and the bottom ,which adjusted from factory is 10μs.It can be reduced by paralling external resistor to inner capacitor to meet different IGBTs and swtiching frequency.The adjusted dead time and the self supplied dead time by the control signal won't work at the same time, the longer one always take effect.
The interlock function be canceled in the indepedent mode.
Attention:If the error reset is PWM signal input double-two reset ,and the dead time of signal control should belower than it. For example, PSHI 23 is 5μs,so the dead time should be less than it to protect the IGBT because of the failure of error memory.
The interlock function be canceled in the indepedent mode. |
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| Gate voltage: |
| The gate voltage of drives are divided into +15V / -8V and +15V / -15V. |
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| Narrow-pluse control: |
| PSHI driver contain a 500ns narrow pulse supression circuit to eliminate radio frequency interference except for the special high types. |
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| DC/DC power supply: |
An internal DC/DC power supply for driving supply isolation power supply with output voltage,which make the driver get enough gate voltage without external isolation power supply.The drivers and controlled system can use the same power supply(+15V),
even if we are using more than one drivers. |
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| Over current and short circuit protection: |
"VCE monitoring circuit" is responsible for short-circuit sensing.Due to the direct measurement of VCEsat on the IGBT's collector, it cut off IGBT and block the output buffer through the soft turn-off circuit in case of short-circuit and send a signal to error memory
on the primary side.
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| IGBT short circuit and "soft turn-off": |
| In case of short-circuit, a further circuit increases the resistance in series with Rgoffand turns- off the IGBT at a lower speed.This produces a smaller peak voltage by reducing the di/dt value.Because in short-circuit conditions the Homogeneous IGBT's peak current increases up to 6-8 times the nominal current, and some parasitic inductance is always present in power circuits, it must fall to zero in a longer time than at normal operation to avoid the damage caused by voltage spike to IGBT. |
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| Under-voltage protection: |
| "The undervoltage protection" ensures that Vs actual is not below 13V.Once Vs below 13V, system will blocks the transmission of all input signals to the IGBT. |
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| Dynamic peak restrained function( or active clamp): |
| In a variety of devices, the reverse recovery of diode ,the electro-magnetic behavior distrbution load capacitance,turn-off snubber circuit and stray indutance can lead to peak voltage in the switch and turn-off of IGBT.When the peak voltage exceeds the preset ,the peak restrain plus a reverse gate signal to reduce it after judging out the the type of the peak. |
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