MGC3140 datasheet(34/49 Pages) MICROCHIP

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Application Architecture

The standard MGC3140 application architecture consists of a MGC3140 controller connected to external

electrodes and an application host. For further information on the electrode design, refer to “GestIC

Design Guide” (DS40001716). Details on the I2C interface can be found in “MGC3140 - GestIC Library

Interface Description User’s Guide” (DS40001875).

8.1

ESD Considerations

The MGC3140 provides Electrostatic Discharge (ESD) voltage protection up to 4 kV (HBM) and Charge

Device Model (CDM) 750V on corner pins; 500V on all other pins. Additional ESD countermeasures may

be implemented individually to meet application-specific requirements.

8.2

Power Noise Considerations

MGC3140 filtering capacitors are included in the reference design schematic.

8.3

High-Frequency Noise Immunity

In order to suppress irradiated high-frequency signals, the five Rx channels of the chip are connected to

the electrodes via serial 10 kΩ resistors, as close as possible to MGC3140. The 10 kΩ resistor and the

MGC3140 input capacitance are building a low-pass filter with a corner frequency of 3 MHz. An additional

ferrite bead is recommended to suppress the coupling of RF noise to the Tx channel (e.g., 600Ω at 100

MHz).

8.4

RF Emission

The Tx pins are used to shape the Tx signal and reduce emission in relevant frequency bands. The slope

of the Tx signal is randomized using dithering techniques while the sampling point is kept constant for

further reduction of emission. In addition, a RC network on the Tx output will reduce the emission even

further. For further support on reduction of RF emission, contact your local Microchip representative.

MGC3140

Application Architecture

DS40002037A-page 34

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