INA290: What is the max PWM switching frequency can INA290 be used in?

Hi Shengnan,

why not running a TINA-TI simulation?

First a 10kHz square wave input signal:

Then a 100kHz square wave input signal:

shengnan_ina290.TSC

Kai

Hello Shengnan,

. If I use INA290 in series with the inductor in a boost circuit, for peak current mode control. Since its bandwidth is 1.1Mhz, what is the max pwm switching frequency boost can switch at ?

Even though the bandwidth is 1.1MHz you need to account for the AC CMRR and the slew rate of the switching.  If the VCM is not changing depending on the placement of the Rshunt then you will not need to look into this.  If the placement does have a large VCM you may look into the INA240.

2. if I use average current mode control, is it different?

Yes it will be different if the average current is lower and the bandwidth is limited by the input voltage as you showed from Figure 7-2 that you placed in this post.  One way to battle this is to create and offset by adding a resistor on the In- pin.  Doing this will create an offset and gain error. 

3. INA290 is supplied with 3.3V power, the output goes to a micro for digital control. I found that within 1V output, the bandwidth is really low. so i am wondering this part is really not meant for digital control?

I would suggest maybe the INA240.  Or attempting the options above.

Regarding simulation the INA290 model does not account for the low Vsense bandwidth limitation.