doogg
Newbie level 1
Hi,
I am working on LCDCO design. We can program oscillation frequency by programming switched capacitor array. We find different cap curve vs sweep code with CC and RCC netlist, shown as attached figure. I apply AC current and measure imaginary voltage to calculate capacitor. The measure state is shown as follows. I use same method to simulate cap in different process. It don't have this issue. I am using new advanced process. I am wondering if the RCXT is wrong. But I can't make sure about this. From my knowledge, parasitic R should not affect equivalent capacitor. Can someone help this issue? Thanks.
.meas AC vm_crs Find vm(crsout) at=freq1
.meas AC vr_crs Find vr(crsout) at=freq1
.meas AC Q_crs param='vm_crs/vr_crs'
.meas AC C_crs param='1/(2*3.1416*freq1*vm_crs)'
I am working on LCDCO design. We can program oscillation frequency by programming switched capacitor array. We find different cap curve vs sweep code with CC and RCC netlist, shown as attached figure. I apply AC current and measure imaginary voltage to calculate capacitor. The measure state is shown as follows. I use same method to simulate cap in different process. It don't have this issue. I am using new advanced process. I am wondering if the RCXT is wrong. But I can't make sure about this. From my knowledge, parasitic R should not affect equivalent capacitor. Can someone help this issue? Thanks.
.meas AC vm_crs Find vm(crsout) at=freq1
.meas AC vr_crs Find vr(crsout) at=freq1
.meas AC Q_crs param='vm_crs/vr_crs'
.meas AC C_crs param='1/(2*3.1416*freq1*vm_crs)'
