3 ms·
Bandgap reference can't tell anything about body bias voltage, unless it itself built on top of insulator
by baybal2 5y ago
Bandgap reference can't tell anything about body bias voltage, unless it itself built on top of insulator
- pjc50 5y agoCould you elaborate? Isn't the substrate usually tied to ground so we can ignore it in modelling? Or are you saying that it could be floated separately to ground in order to attack the chip?
- baybal2 5y agoYes, and normally it is. I think on every moderately modern CMOS IC, body bias is controlled. > What is body bias? > Body bias is used to dynamically adjust the threshold voltage (Vt) of a CMOS transistor. While CMOS transistors are usually thought of as having three terminal devices, with terminals for the source, gate, and drain, it’s increasingly common to have a fourth terminal connected to the body (substrate). Because the voltage difference between the source voltage (Vs) and body voltage (Vb) affects the Vt, the body can be thought of as a second gate that helps determine how a transistor turns on and off. https://semiengineering.com/body-bias-what-it-is-and-why-you-should-care/ https://semiengineering.com/body-bias-what-it-is-and-why-you...