Selection of the TX cascade driver

[JoyJo]

I would like to know the opinion of the forum members regarding the TX cascade driver.
1. The TX cascade is supposed to be with a non-resonant TX coil.
2. The coil will be controlled by a half-bridge 2N-channel mosfet relative to the minus power supply (ground).
3. The power supply of the driver chip itself must be 5V.
4. An adjustable voltage of 20 to 40 (50) V will be applied to the half-bridge
I selected the half-briss driver chip based on the availability of the chip and its soic-8 body.
As a result, I chose driver UCC27201.
I know there is also a good HIP2103 driver, but you can't buy it freely.

Now the moments in which I doubt:
1. The only thing that confuses me is that according to the scheme from the datasheet, this driver controls the midpoint of which, in fact, is connected to the positive power supply. In my case, the midpoint of the MOSFets will be connected to the coil TX, the second end of the coil TX will be connected to the ground.
In addition, the shutters of the MOSFets will be connected to the driver through resistors shunted by Schottky diodes.

2. Jitter (signal phase shaking). Won't this driver contribute jitter to the formation of the transmission signal?

I would like to know your opinion.

[Detectorist#1]

Hi JoyJo,
The MOSFETs haves Gates, Sources and Drains. Which is the "shutter" end, maybe the Gate? With these type of drivers is not possible to connect second end of the TX coil to GND. Lower MOSFET, when is open, will shunt the TX coil.

[JoyJo]

What's strange? The hip2103 driver is just installed in Equinox and it controls the assembly of ao4882 mosfets. And everything works fine. One output of the TX coil is connected to the midpoint of the MOSFets, the second output of the TX coil is connected to the ground.

[Marchel]

Why complicate it, the XP Deus FMF coil has an H-Bridge connected via 10R resistors directly to the GPIO on the processor and the detector works great.

[JoyJo]

I only saw the deus board in the photo, but I couldn't see the MOSFET brand. Do you have a MOSFET marking from deus? Maybe they use drmos?

[JoyJo]

And in dues with a full bridge, is the current phase measured in the TX coil? In Equinox, one channel of an external two-channel ADC is allocated for these purposes.

[JoyJo]

Hi JoyJo,
The MOSFETs haves Gates, Sources and Drains. Which is the "shutter" end, maybe the Gate? With these type of drivers is not possible to connect second end of the TX coil to GND. Lower MOSFET, when is open, will shunt the TX coil.

I completely forgot to mention an important point. The electrolytic capacitor of 100-200 mkF will be included sequentially with the TX coil.

[Marchel]

I only saw the deus board in the photo, but I couldn't see the MOSFET brand. Do you have a MOSFET marking from deus? Maybe they use drmos?

I tested these transistors and everything worked fine.

https://www.ti.com/lit/ds/symlink/cs...=1757583218840
https://www.ti.com/lit/ds/symlink/cs...=1757609949156

[Marchel]

And in dues with a full bridge, is the current phase measured in the TX coil? In Equinox, one channel of an external two-channel ADC is allocated for these purposes.

XP Deus 1 or 2 do not measure TX coil current.

[Marchel]

Here are XP Deus FMF photos of the PCB to show how simple it all is.

https://device.report/m/a47bb465c235...2bfdddf9461459

[pito]

PCB to show how simple it all is.

or this - simple

[JoyJo]

Oh, they use a full bridge on n/p MOSFETs. The use of only n channel MOSFETs would make it even more economical. But it doesn't matter. Thank you for the information. And do you have any data on the coil Rx and Tx: inductance, resistance, wire diameter. Th, it will most likely be wrapped in litzendrate.

[JoyJo]

or this - simple

Judging by the two rows of landing holes, the board is adapted for the use of a ready-made module with a microcontroller. The tracing of these modules is far from ideal. Is it possible to see the diagram of the device whose boards you demonstrated?

[JoyJo]

XP Deus 1 or 2 do not measure TX coil current.

Is the supply voltage of the full bridge adjustable? Or in deus, the value of the current in the TC coil changes by adjusting the duty rod of the control signals: pwm?

[Marchel]

Is the supply voltage of the full bridge adjustable? Or in deus, the value of the current in the TC coil changes by adjusting the duty rod of the control signals: pwm?

The H-Bridge is permanently powered by 3.3V and everything is controlled by PWM. Watch this video to see the signal flow.

https://www.youtube.com/watch?v=E2AYJp2uH2U&t=437s