Generating low-voltage reference CMOS 0.18um

[yippie]

Hello all,

I need to generate the following voltages (DC) for a DAC I'm creating (split capacitive DAC).

1.4, 1, 0.8, 0.4V

The DAC is dual scale, and will operate between 0.4 and 1.4V in one mode and 0.8 and 1V in another.

Can anybody recommend me a good method on how to achieve these voltages? I have a Vdd of 1.8 and Vss of 0V. Using 0.18um process.

Thanks
Yippie

 

[yippie]

Accurate 0.5V reference on 0.18um process

Hello all,

I'll keep this short and simple:
How can I accurately generate a 500mV reference voltage. I have a Vdd of 1.8V (Vss = 0). Would a bandgap generate with resistors be any good?
I will be using the 500mV as the input to a summing op-amp circuit



Thanks
Yippie

 

[Dominik Przyborowski]

The standard BG reference based on Vbe of BJT and silicon bandgap produce around 1.2V, but is many solutions for lov voltage BG referenmce using mosfets in subthreshold region generate a reference voltage in a range of 0.3-0.6V. Using these BGR You are able to generate any volatge using OTA with proper resistive network.

 

[OTA_LDO]

A Beta Multiplier circuit could also be used, but it is not as accurate as a bandgap with respect to temperature and process variations

 

[erikl]

Re: Accurate 0.5V reference on 0.18um process

How can I accurately generate a 500mV reference voltage. I have a Vdd of 1.8V (Vss = 0). Would a bandgap generate with resistors be any good?

See this PDF: View attachment Sub-1V_CMOS_BGA.pdf

 

[ZekeR]

Re: Accurate 0.5V reference on 0.18um process

See this PDF: View attachment 99014

Gee, I wonder why they didn't simulate over corners?

Yippie, use the circuit of Figure 1.a.