MMA6222EG

Sensors

Freescale Semiconductor

5

1.4

PIN FUNCTION DESCRIPTIONS

1.4.1

This pin supplies power to the device. Careful printed wiring board layout and capacitor placement is critical to ensure best per-

1.4.2

This pin is the power supply return node for the digital circuitry on the MMA62XXEG device.

1.4.3

This pin is the power supply return node for analog circuitry on the MMA62XXAEG device. An external bypass capacitor between

1.4.4

This pin is connected to the internal digital circuitry power supply rail. An external filter capacitor must be connected between this

1.4.5

These pins are connected in parallel to the internal analog circuitry power supply rail. One or two external filter capacitors must

to the printed wiring board assembly. Redundant external capacitors may be connected to these pins for maximum reliability, as

described in Section 1.5.

1.4.6

These pins are connected in parallel to an internal reference voltage node utilized by the analog circuitry. One or two external

support redundant connection to the printed wiring board assembly. Redundant external capacitors may be connected to these

pins for maximum reliability, as described in Section 1.5.

1.4.7

VPP

1.4.8

SCLK

This input pin provides the serial clock to the SPI port. The state of this pin is also used as a qualifier for externally-controlled

reset. An internal pull-down device is connected to this pin. This input may be left unconnected unless it is desired to initiate de-

vice reset as described in Section 1.4.9.

1.4.9

CS/RESET

This pin provides two functions. When the SPI is enabled, this pin functions as the chip select input for the SPI port. The state of

This pin may also be used to initiate a hardware reset. If CS is held low and SCLK is held high for 512

μs, the internal reset signal

is asserted.

An internal pull-up device is connected to this pin.

1.4.10

This pin functions as the serial data output for the SPI port.

system can be aware of potential difficulties if unexpected resets occur.

1.4.11

This pin functions as the serial data input to the SPI.