Current Limit 6 Click Board™

How Does The Current Limit 6 Click Board™ Work?

The Current Limit 6 Click Board™ as its foundation uses the MAX17608, a current-limiting device with an adjustable overvoltage and overcurrent protection feature from Maxim Integrated, now part of Analog Devices. The MAX17608 offers flexible protection boundaries for systems against input voltage ranging from 4.5V to 60V and limits the output load current to a programmed level (up to 1A). The devices also feature two internal MOSFETs connected in series, with a low cumulative RON of 260mΩ typical. Input undervoltage protection can be programmed between 4.5V and 59V, while the overvoltage protection can be independently programmed between 5.5V and 60V (default Click board™ configuration is 4.5V for UVLO and 14V for OVLO). Additionally, the MAX17608 has an internal default undervoltage lockout set at 4V typical.

The current-limit switch is virtually ubiquitous in system control and provides a safe means for regulating the current delivered to a load circuit. It allows the load current to increase to a programmed limit but no higher. Typically, the current limit is a function of the voltage across an external resistor, and this voltage serves as the reference for an internal current-limiting amplifier. By replacing the resistor with a digital potentiometer, you can easily program the current limit as performed on this Click board™. For this purpose, the digital potentiometer MAX5401 from Maxim Integrated, which communicates with the MCU via 3-Wire SPI serial interface, is used to set the resistance on the MAX17608 SETI pin, adjusting the current limit for the switch between 0.1A to 1 A.

This current limiter offers several operational modes, selectable through a populated jumper labelled as R11 connected to the CLMD pin of the MAX17608. In a default configuration, this pin is connected to the ground, representing the Continuous mode of operation. When R11 is replaced with a 150kΩ resistor, this Click board™ is in the Latch-off mode, and when the user leaves this pin unconnected Autoretry mode of operation is activated. More information on the operational modes can be found in the attached datasheet.

The Current Limit 6 Click Board™ can be enabled or disabled through the EN pin routed to the PWM pin of the mikroBUS™ socket; hence, offering a switch operation to turn ON/OFF power delivery to the connected load. It also provides communication signals routed to the INT and AN pins of the mikroBUS™ socket, alongside its LED indicators labelled as ER1 and ER2, to indicate different operational and fault signals such as FLAG and UVOV signals. Besides, the MAX17608 also offers internal thermal shutdown protection against excessive power dissipation.

The Current Limit 6 Click Board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout for the Current Limit 6 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin		Pin	Notes
UVLO/OVLO Indicator	ER2	1	AN	PWM	16	EN	Enable
NC	2	RST	INT	15	ER1	Fault Indicator
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
NC	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

ONBOARD SETTINGS AND INDICATORS

CURRENT LIMIT 6 CLICK ELECTRICAL SPECIFICATIONS