± 14V swicth in 3V process with 3V vdd.

[tekno1]

I am using a process with 15V capable MOSFETS and I want to connect a switched capacitor amplifier directly to input through ± 14V capable switch. Vdd is 3V.


Could you suggest me a suitable topology, paper, working circuit etc. I worry about particularly latch-up issues. Is it doable? thank you in advance.

 

[A.Anand Srinivasan]

when you are talking about that 14V capable MOSFET i believe you are talking about a discrete one... if it not discrete and if it is used in the wafer along with the 3V MOSFET then it is a very risky operation in terms of latchup.....

 

[tekno1]

The ± 15V device is not discrete one, it exist in the process. Is there any circuit anybody know that works. I can come up with one but I need comments from people who has experience to share. thanks again.

 

[A.Anand Srinivasan]

post your circuit,.... generally many process are done to prevent latchup from occuring which can be easily found by googling too...

 

[garfield]

Check this site , may be useful to you :


http:// www.nomad.ee/micros/mc34063a/index.shtml

you can use two ic , one for -B and other for +B

sorry if I don't understand the concept of your question.

regards-

 

[tekno1]

srinavasan

I do not have a solution yet. I was hoping an engineer with a previous experience could give me a lead.

garfield

Question is regarding IC design so I can not utilize external IC's.

thank you very much for your kind replies and efford

 

[A.Anand Srinivasan]

try reading this....

**broken link removed**

in it some methods for preventing latchup has been discussed... i had some documents... i'll find them and post them somehow....

 

[yuanxiao]

bootstrap

sometimes used in power management circuits to
control the external power switch

 

[tekno1]

@ yuanxiao

Due to device breakdown voltage limit there is no room for boostrapping. Also this will require a large area HV charge pump. I am stuck with p-ch switch but there may be some clever way as add on to it to accomplish a neat solution.

thanks for your reply.