Replacement Part for HV9150 to create HV from Li Cell

[joshp]

We've been using the HV9150 (https://www.digikey.com/en/products/detail/microchip-technology/HV9150K6-G/4902803) in our design to convert a single cell Li battery voltage to both a high negative and positive voltage. Unfortunately, the chip seems like it's going EOL   

Does anyone know of a replacement chip that meets the following requirements? I've tried using AI to help with this, but it doesn't give very good answers...

Vin: 2.9V -> 4.5V
Vout: >= +/- 75V
Current: ~10 mA
Size: ~3x3mm
Price: $1-2 (at scale is fine)

[dmendesf]

Needs to be regulated? A small transformer can be used? There's a bunch of chinese chips that clone some Texas chips that generates isolated voltages... usually a bit higher or lower than input. But as there's no regulation it's just a matter of messing with the turns ratio. These are the original:

https://www.ti.com/product-category/isolation/power-for-signal-isolators/transformer-drivers/overview.html

Look at LCSC for the clones.

[joshp]

It will likely need to be manufactured in a high quality fab (e.g. TI, AD, Microchip, etc.) as it's a central component. I don't think we have room for two transformers in the small-form-factor case. Our current tallest component is the 3mm inductor. We'll also need both arms of the voltage to be regulated (not passive regulation on a single arm)... I also believe one of our engineers raised concerns about potential distortion for a two sided transformer (voltage sag)

[dmendesf]

Yes, you can center tap, use 2 diodes.and have only one transformer. Voltage regularion is tricky. If power consumption of both sides varies at the same time there are ways (a jim williams app note comes to memory:)

https://www.analog.com/en/resources/app-notes/an-118fb.html

It's A Royer oscillator. Surelly it can be made simpler.

A.chip like the Texas.with an optocoupler output transistor in parallel with vcc.(amd a small series resistor feeding both) that drains current lowering available voltage if output voltage gets too high... it's late here and.maybe the general idea woks but the details are messed up but I think you understood.