PN5190 datasheet describes the supply voltage range
1.When VBAT and VBAT_PWR pins of our PN5190 chip are connected to lithium battery for direct power supply, after EMVco_L1_3.1 certification, the field strength test of NFC will attenuate with the decrease of lithium battery power, so that the field strength test of NFC cannot pass. I would like to ask whether stable 3.3V power supply is recommended for these two pins of PN5190 chip or lithium battery power supply (lithium battery voltage range 3.7V ~ 4.4V) can be used directly. If so, what are the advantages and disadvantages of lithium battery power supply and stable single power supply?
2.The test now uses NXP NFC Cockpit tools for the opening test to ensure that the core NFC field intensity is maximum at 4cm, and the chip temperature is between 70℃ and 85℃. Is this working temperature reasonable? Will the chip temperature increase affect the temperature drift of the components of the NFC impedance matching circuit, thus attenuating the field strength of the NFC?