Hi Guys,
I'm using ZXMHC10A07N8 to alternate a current through a resistive load. The IC is an 8 pin package containing 2 N channel and 2 P channel MOSFETs.
Datasheet is here: http://www.diodes.com/_files/datasheets/ZXMHC10A07N8.pdf
I've uploaded my current SPICE model, where you can hopefully see the problem. The H-bridge appears to be shorting itself due to the PMOSFETs slow turn on time upon powering up the circuit. (in my spice model as U1, pin 3 and pin 7)
The first IC is used as the H bridge, a second identical IC is used for its n-channels to control the p channels on the first IC. This is because my incoming driver signal is a pulsed 5V and my H-bridge Voltage is 24V. The P channels have pull-up resistors to Vin (24V). The smaller I make these Pullup resistors, the faster the turn on times. I don't really understand why this is, as the MOSFETs seem to all have low gate charges. Any explanation that could help my understanding would be hugely appreciated.
If anyone could offer some guidance as to what is wrong with the current circuit, I would be thrilled. I've spent all morning trying to figure out what is going on without much progress.
I've probably forgotten to include something crucial, so let me know.
Thanks so much,
Dom
I've also included the spice model for the IC as I cannot remember how to include it directly in the SPICE file.
I'm using ZXMHC10A07N8 to alternate a current through a resistive load. The IC is an 8 pin package containing 2 N channel and 2 P channel MOSFETs.
Datasheet is here: http://www.diodes.com/_files/datasheets/ZXMHC10A07N8.pdf
I've uploaded my current SPICE model, where you can hopefully see the problem. The H-bridge appears to be shorting itself due to the PMOSFETs slow turn on time upon powering up the circuit. (in my spice model as U1, pin 3 and pin 7)
The first IC is used as the H bridge, a second identical IC is used for its n-channels to control the p channels on the first IC. This is because my incoming driver signal is a pulsed 5V and my H-bridge Voltage is 24V. The P channels have pull-up resistors to Vin (24V). The smaller I make these Pullup resistors, the faster the turn on times. I don't really understand why this is, as the MOSFETs seem to all have low gate charges. Any explanation that could help my understanding would be hugely appreciated.
If anyone could offer some guidance as to what is wrong with the current circuit, I would be thrilled. I've spent all morning trying to figure out what is going on without much progress.
I've probably forgotten to include something crucial, so let me know.
Thanks so much,
Dom
I've also included the spice model for the IC as I cannot remember how to include it directly in the SPICE file.
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