6 years, 6 months ago.

programming digital programmable capacitor

Hello everyone,

first of all i would like to say that i am a beginner with MBED systems so everything is new to me and i might be using wrong terminology or am being unclear, sorry for that and thank you.

i have a STmicroelectronics NUCLEO-F446ZE board (/media/uploads/sivan/manual.pdf) and i am using STM32CubeMX and IAR Embedded compiler. i am trying to program and operate a digital programmable capacitor (/media/uploads/sivan/ncd2100-515357.pdf) which is a chip with some capacitors on it and using serial communication one can change the capacitance for ones needs.

as i understood it i need a power and ground lines (pin 9 and 11 on CN8 on my board) that i connect to VDD and Vss. and 3 lines for programming and operating (DA, PV and CLK) which i connected to PA3, PC3 and PC0 as they are close together and therefore easily reached.

i am now trying to write the code to program the capacitance and i got really confused about how to do that. do i need to continuously toggle the CLK pin? do i send the bit values one by one or as a binary number with 1's and 0's on the bits i want on or off? how do i time the CLK with the DA pin?

if anyone has some experience with these capacitors or can help me just by looking at the datasheet i would really appreciate it.

thank you,

Sivan