SolidSwitch Click Board™

How Does The SolidSwitch Click Board™ Work?

The SolidSwitch Click Board™ is based on the TPS22918, a 5.5V 2A load switch from Texas Instruments. To reduce voltage drop for low voltage and high current rails, every TPS22918 implements a low resistance N-channel MOSFET, reducing the drop-out voltage across the device. An ON/OFF input on the ON pin of the TPS22918 controls the switches. The ON pin is compatible with the standard GPIO logic threshold and can be used with any MCU with 1V or higher GPIO voltage. That's why the control of all switches is established via the port expander, the MAX7323.

This Click board™ is designed to operate from an external supply voltage range from 1V to 5.5V. The TPS22918 works regardless of power sequencing order. The order in which voltages are applied to the VIN terminal and ON pin of the load switch will not damage the device as long as the voltages do not exceed the absolute maximum operating conditions.

The SolidSwitch Click Board™ communicates with MCU through the MAX7323 port expander using the standard I2C 2-Wire interface with a frequency of up to 400kHz. It also has two address pins (A0 and A1) programmed by the user to determine the value of the last two LSBs of the slave address, selected by onboard SMD jumpers labelled as ADDR SEL to an appropriate position marked as 0 and 1, allowing selection of the slave address LSBs. Also, this Click board™ has a Reset pin, routed to the RST pin on the mikroBUS™ socket, which clears the serial interface in case of a bus lockup, terminating any serial transaction to or from the MAX7323.

Also, it uses an additional pin, the INT pin of the mikroBUS™ socket, which automatically flags data changes on any of the I/O ports of the MAX7323 used as inputs. The interrupt output INT and all transition flags are deasserted when the MAX7323 is accessed through the serial interface.

The SolidSwitch Click Board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout of the SolidSwitch Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
NC	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	INT	Interrupt
NC	3	CS	RX	14	NC
NC	4	SCK	TX	13	NC
NC	5	MISO	SCL	12	SCL	I2C Clock
NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

ONBOARD SETTINGS AND INDICATORS

SOLIDSWITCH CLICK ELECTRICAL SPECIFICATIONS