MPR03X

Sensors

Freescale Semiconductor

3

2

External Signal Description

2.1

Device Pin Assignment

Table 1 shows the pin assignment for the MPR03X. For a more detailed description of the functionality of each pin, refer to the

appropriate chapter.

The package available for the MPR03X is a 2 x 2 mm 8 pin

DFN. The package and pinout is shown in Figure 3.

Figure 3. Package Pinouts

2.2

Recommended System Connections

The MPR03X Capacitive Touch Sensor Controller requires one external passive component. As shown in Table 1, the REXT line

should have a 75 k

connected from the pin to GND. This resistor needs to be 1% tolerance.

In addition to the one resistor, a bypass capacitor of 10 µF should always be used between the VDD and VSS lines and a

4.7 k

 pull-up resistor should be included on the IRQ. Note: This condition is when pin 8 is used for interrupt indication and not

for electrode sensing.

The remaining two connections are SCL and SDA. Depending on the specific application, each of these control lines can be used

by connecting them to a host controller. In the most minimal system, the SCL and SDA must be connected to a master I2C

interface to communicate with the MPR03X. All of the connections for the MPR03X are shown by the schematic in Figure 4.

Table 1. Device Pin Assignment

Pin

Name

Function

1SCL

I2C Serial Clock Input

2SDA

I2C Serial Data I/O

3VSS

Ground

4VDD

Positive Supply Voltage

5

REXT

Reference Resistor

Connect a 75 k

 ±1% resistor from REXT to V

SS

6

ELE0

Electrode 0

7

ELE1

Electrode 1

8IRQ/ELE2

Interrupt Output or Touch Electrode Input 2

IRQ is the active-low open-drain interrupt output

1

SCL

2

3

8

7

6

5

4

SDA

VSS

VDD

IRQ/ELE2

ELE1

ELE0

REXT

MPR03X

Interface

I²C Serial

3

VSS

SDA

SCL

MPR03X

ELE0

ELE1

IRQ/ELE2

1

2

VSS

75k

VDD

REXT