The LMH6521 was designed primarily to be operated on 5-V power supplies. The voltage range for V_CC is 4.75 V to 5.25 V. When operated on a board with high-speed digital signals, it is important to provide isolation between digital signal noise and the LMH6521 inputs. 700-2700 MHZ Dual-Channel Receiver with 16-Bit ADC and 100 MHz IF Bandwidth Reference Design (TIDA-00360) provides an example of good board layout.