2 Reference Circuit

The following figure illustrates a typical reference circuit diagram of the ATA5352. A standard lithium battery, for example CR2032, can provide the IO voltage between 2.0V and 3.5V. The core voltage of 1.25V is generated by a DC/DC converter for optimized overall power consumption.

The host microcontroller controls the ATA5352 via the SPI interface. If required, the host can derive a high precision clock from the 48 MHz crystal of the ATA5352.

The RFIO pin of the device has an impedance of 30Ω. The application of this pin when matching to a 50Ω antenna requires the following components:

  • High-Q wire wound coil inductor with a Self-Resonant Frequency (SRF) >12 GHz (recommended size 0402).
  • 30Ω-to-50Ω matching network including a High-Q capacitor (recommended size 0201). It is recommended that the microstrip and co-planar lines be used to achieve the required matching.
The following reference circuit illustrates an example implementation including the component values to achieve the required matching.
Figure 2-1. ATA5352 Reference Circuit Diagram