SLWS213A January 2010 – November 2015 TRF370417
The TRF370417 device is fitted with a ground slug on the back of the package that must be soldered to the printed circuit board (PCB) ground with adequate ground vias to ensure a good thermal and electrical connection. The recommended via pattern and ground pad dimensions are shown in Figure 76. The recommended via diameter is 10 mils (0.10 in or 0.25 mm). The ground pins of the device can be directly tied to the ground slug pad for a low-inductance path to ground. Additional ground vias may be added if space allows. Decoupling capacitors at each of the supply pins are strongly recommended. The value of these capacitors should be chosen to provide a low-impedance RF path to ground at the frequency of operation. Typically, the value of these capacitors is approximately 10 pF or lower. The device exhibits symmetry with respect to the quadrature input paths. TI recommends that the PCB layout maintain this symmetry to ensure that the quadrature balance of the device is not impaired. The I/Q input traces should be routed as differential pairs and the respective lengths all kept equal to each other. On the RF traces, maintain proper trace widths to keep the characteristic impedance of the RF traces at a nominal 50 Ω.
Figure 44 shows the top view of the TRF3704 EVM board.