18

NXP Semiconductors

33982

FUNCTIONAL DESCRIPTION

DIGITAL DRAIN VOLTAGE POWER (VDD)

This is an external voltage input pin used to supply power to the SPI circuit. In the event VDD is lost, an internal supply provides power to

a portion of the logic, ensuring limited functionality of the device. All device configuration registers are reset.

SERIAL OUTPUT (SO)

This output pin is connected to the SPI Serial Data Input pin of the MCU or to the SI pin of the next device in a daisy chain of devices.

This output remains tri-stated (high-impedance OFF condition) so long as the CS pin of the device is logic High. SO is only active when

the CS pin of the device is asserted logic Low. The generated SO output signals are CMOS logic levels. SO output data is available on

the falling edge of SCLK and transitions immediately on the rising edge of SCLK.

POSITIVE POWER SUPPLY (VPWR)

This pin connects to the positive power supply and is the source input of operational power for the device. The VPWR pin is a backside

surface mount tab of the package.

HIGH-SIDE OUTPUT (HS)

This pin protects high-side power output to the load. Output pins must be connected in parallel for operation.