Greetings to all, I have previously tested and burned the FB4 component on of the HMC767LP6CE device. Noting the difference between PCB and datasheet (on the pcb where there is 15V for the tuning voltage and 5.5V for the VCO voltage while 13V and 5.25V max as VCO on the datasheet), I wanted to know to which maximum threshold I have to limit myself, to avoid the burnt of the device if there is some electronics below that brings the voltage to that value. Can someone help me with this problem?
On the HMC767 eval board apply 15V at TP4 to power the active loop filter op-amp (U5) and 5.5V at TP3 to power all other rails.
The 5.5V voltage at the input of U2 (HMC976) is regulated down to the required 5V for the VCO.
The Vtune input (pin 6) on the HMC767 is driven by the op-amp output. This pin can tolerate up to 15V but in practice, due to the TLS4031 op-amp headroom, the max Vtune voltage will be limited to around 13.6V.