ModulatorThe contactless interface utilizes absorption modulation of the LF Field on all three channels simultaneously to send data to the base station. The modulation timing is determined by the RISC controller.Absorption modulation is accomplished by applying an additional load (S2 closed, see Figure 11) across the coil inputs. The LF field modulator contains a standard modulator and a strong modulator. If the standard modulator is selected, the high ohmic path (Rx+LIN, Rx+NLIN and Rx-LIN) is turned on (weak modulation), while selecting the strong modulator, both the low-ohmic path (Rx+LIN_strong and Rx-LIN_strong) and the high ohmic path are enabled (strong modulation).Besides the modulation load impedance, the absorption modulation characteristics depend on the source impedance of the external resonance circuit, the voltage limiter and the internal power consumption of the device. The applied load (S2) is different for each of the two half waves of the carrier, to support clock recovery. The resistors Rx and the switches S1, S2 are implemented for each channel.