3 Replies Latest reply on Jul 24, 2017 2:11 PM by JoMe_264151

Hello everyone
By reference to the first generation of PSoC (PSoC 1),the analog input range is 0-5 volt with AGND equal to 2.5v if Ref Mux=(Vdd/2)+/-(Vdd/2).
by using psoc 5lp , the range is [0-1.020]v or [0-4.080]v ???
also vref =1.020 as default, why that ?why my analog input shouldn't exceeded 4.080 v?
the range in psoc 1 is better than psoc 5,right ?

What is the equivalent of AGND in psoc 5lp ???This is a question in need of an answer.
the problem is :

i worked on psoc1 cy8c29466 with range 0-5 v and agnd=2.5 , i have implemented a big project using it and It works well, i want to development it by using psoc5lp cy8c5888 ,But there is a difference in input voltage range ,and AGND ??

I have attached image about my project using PSoC1

• ###### 1. Re: Basics about PSoC 5LP

With the correct choice the ADC input range is 0 to 5V (Vadd). You may provide a 2.5V reference (DAC) and configure the ADC as differential.

Aamof the ADC within the PSoC5 are more sophisticate than in PSoC1, although the former lacks some analog functionality the PSoC1 has. I would suggest you to start with a CY8CKIT-059  which you can get from a local distri for US\$10. You even could think about using a PSoC4 chip which is a bit smaller than a PSoC5 but still is quite better than the PSoC1.

Bob

• ###### 2. Re: Basics about PSoC 5LP

Q1 :what is the difference between using  vdac8 or vref as a voltage reference ??
vref=vdda/2 (which equal 2.5 v)

< my signal is sine in range [-2.5-+2.5]v with offset=2.5v => the input signal in range [0,5]v arround 2.5v as agnd

• ###### 3. Re: Basics about PSoC 5LP

A1) Using a DAC allows adjusting the voltage at run-time.