DM160218 datasheet(27/50 Pages) MICROCHIP

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Hillstar Boards – Hardware Description

 2013 Microchip Technology Inc.

DS40001721A-page 27

FIGURE 3-5:

PCB LAYER STACK

In a target system design the GND layer is not required. It is added for the Hillstar sens-

ing electrode as a shielding layer and shall simulate the presence of static components

which are placed in a target device underneath the sensing electrodes.

3.4

I2C TO USB BRIDGE

Connecting the MGC3130 Unit to a PC requires an I2C to USB Bridge. The Hillstar

Bridge works as a Composite Device Class (CDC). It controls the USB transfer towards

the host PC and handles the I2C communication with the MGC3130 Unit. Moreover, it

provides 3.3V power supply and the MCLR signal to the MGC3130 Unit.

The bridge function is handled by Microchip’s PIC18F14K50 USB microcontroller.

The board is equipped with a mini USB connector (Type A) and a 2 mm 6-pin female

board-to-board connector for the I2C interface. The interface to the MGC3130 Unit

includes the following signals: EIO0, 3.3V, GND, SDA0, SCL0, and MCLR. Please refer

to Figure 3-6.

FIGURE 3-6:

I2C™ TO USB BRIDGE

Tx: 35 µm

Rx : 18 µm

GND: 18 µm

Not Used: 35 µm

0.25 mm

0.15 mm

Top layer

Bottom

layer

nd layer

rd layer

Rx feeding line

Note: Please refer to the “MGC3130 GestIC® Design Guide” for the electrodes

equivalent circuitry, capacitances (CRxTx, CRxG, TxRxG) and their typical

values.

™

DM160218 Datasheet(PDF) 27 Page - Microchip Technology