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Measurements >> Other Measurements >> 3.3 V to 1.8V level converter
https://designers-guide.org/forum/YaBB.pl?num=1407685042

Message started by aman gupta on Aug 10^th, 2014, 8:37am

Title: 3.3 V to 1.8V level converter
Post by aman gupta on Aug 10^th, 2014, 8:37am

I want to convert a square wave with high level of 3.3 V & low level of 0V to a square wave of high level of 1.8 V and low level 0V. Frequency of square wave is 1 MHz in one case and 25 MHz in other case. I have the circuit for the converter as shown in the figure. I simulated this circuit both in LT Spice & Tina. The circuit simulation is working for 1MHz signal but with some delay. And it is not working for 25 MHz. May be because switching time of BJT is high as compared to period of the signal. Suggest some alternative for that or any modification in the circuit. And also I am reluctant to use any SMD level translator IC.

Title: Re: 3.3 V to 1.8V level converter
Post by raja.cedt on Oct 7^th, 2014, 2:14am

Hello,
Try to check opamp closed loop bandwidth or please show 3 node signals....

or thy this structure which is very common for LV to HV...

Thanks,
Raj.

Title: Re: 3.3 V to 1.8V level converter
Post by aaron_do on Jan 6^th, 2015, 11:59am

If this is a CMOS IC, you can just use I/O transistors in an inverter configuration. In your circuit, the 22k/15k ohm resistors could be limiting your bandwidth...

Aaron