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I want to control my A4988 current limit by controlling Vref.
So I have a idea that using DRV8301 produce 0~5 Vdc to do that but I have no idea how .
Could anyone help me or give me another methods to achieve this ?
Thanks !!!!
The DRV8301 is designed to drive the power stage to a 3-phase motor inverter. It is a good part, and we have diagrams to support it, but it would not be suitable for producing a simple 0-5Vdc.
I don't know what MCU you are using, but many TI MCUs have on-chip buffered DACs and they are fully supported by Altair Embed. They nominally produce values from 0-3V but can produce values from 0-4.3Vdc if you supply 4.6Vdc to the VDAC pin, which may be enough for you. Otherwise you can use an op-amp to amplify the nominal DAC output to 5Vdc.
I am using TI F28069M, do you have any Embed example for DACs?
BTW, I make sure I need 2.7~5Vdc, so your suggestion is very helpful for me.
Thank you very much.
I am using TI F28069M, do you have any Embed example for DACs? BTW, I make sure I need 2.7~5Vdc, so your suggestion is very helpful for me. Thank you very much.
Unfortunately, the F28069 does not have buffered DACs. Is Vref something you will want to change dynamically? If not, you can just set a resistor bridge across 5V to get the Vref you want.
If you want to vary the voltage dynamically, you could use an external DAC and connect via SPI or I2C: https://www.ti.com/product/DAC80504
Or you can use an RC circuit to filter a PWM: https://www.ti.com/lit/pdf/spraa88
Are you designing a board or just putting together a wired prototype?
Unfortunately, the F28069 does not have buffered DACs. Is Vref something you will want to change dynamically? If not, you can just set a resistor bridge across 5V to get the Vref you want. If you want to vary the voltage dynamically, you could use an external DAC and connect via SPI or I2C: https://www.ti.com/product/DAC80504 Or you can use an RC circuit to filter a PWM: https://www.ti.com/lit/pdf/spraa88 Are you designing a board or just putting together a wired prototype?
Using an RC circuit look suitable for me .
I just putting together a wired prototype and do something like mechatronics~
Thanks you so much !
Hi Robbert,
Unfortunately the F2806x series does not have a buffered DAC. If your desired Vref is not dynamically changing, you can use a resistor bridge to 5V to give you the desired Vref.
For dynamic voltage output you can use one of several methods:
