Can Vth of MOS be lowered for lower input voltages?

  • Thread starter Thread starter shaikss
  • Start date Start date
Click For Summary

Discussion Overview

The discussion centers around the mechanisms for lowering the threshold voltage (Vth) of MOSFETs to accommodate lower input voltages, specifically around 100mV, in the context of designing a rectifier. Participants explore various approaches and considerations related to this topic.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about different mechanisms to lower or cancel Vth for MOSFETs in low-voltage applications.
  • Another suggests that using a low-noise amplifier (LNA) might be a potential solution, referencing external resources.
  • A participant raises a question about the availability of an external power supply, indicating that the feasibility of the design may depend on this factor.
  • It is noted that Vth can typically be adjusted through Boron threshold adjustment implants for NMOS and the opposite for PMOS, but this is limited by fixed boron doses in standard processes, which only yield MOSFETs with a fixed Vth unless specific instructions are given to the fabrication labs.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of lowering Vth, with some suggesting methods while others highlight limitations and conditions that may affect the outcome. The discussion does not reach a consensus on the best approach or the implications of the proposed methods.

Contextual Notes

Limitations include the dependency on fabrication processes and the fixed nature of boron doses in standard IC processes, which may restrict the ability to adjust Vth without explicit instructions to the fabrication labs.

shaikss
Messages
32
Reaction score
0
Hi,

I want to design a rectifier for lower input voltages in the order of 100mV.
So, in order to achieve the same, when I use MOS, I want to lower the Vth.
What are the different mechanisms that are implemented in order to lower/cancel the Vth?

Thanks!
 
Engineering news on Phys.org
The question is whether he has external power supply to power up anything. If so, that is going to be easy. If not, then it's going to be very hard.
 
Usually Vth is adjusted by Boron threshold adjustment implant for NMOS and vice-versa for PMOS. This thing is included in standard process steps in today's IC process. However, the boron dose is fixed and this generates only one kind of MOS with fixed Vth.

Unless you explicitly tell fab labs to use different dosage, you cannot change Vth.
 

Similar threads

  • · Replies 31 ·
2
Replies
31
Views
3K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 25 ·
Replies
25
Views
3K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 20 ·
Replies
20
Views
5K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K