Current Limit 6 Click is a compact add-on board representing a current-limiting solution. This board features the MAX17608, adjustable overvoltage, and overcurrent protection device from Analog Devices. This Click board™ is ideal for protecting systems with the flexible input overvoltage protection range from 4.5V to 60V, and the adjustable input undervoltage protection range is 4.5V to 59V. Also, the maximum current limit is 1A and can be programmed through a digital potentiometer MAX5401. When the device current reaches the programmed threshold, the device prevents further current increases by modulating the FET resistance. This Click board™ is suitable for applications in portable equipment, process instrumentation, and condition monitoring, or with power supplies, protecting them in a short circuit or other overload conditions.

Current Limit 6 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Current Limit 6 Click as its foundation uses the MAX17608, a current-limiting device with an adjustable overvoltage and overcurrent protection feature from 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 Analog Devices, 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 labeled 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.

Current Limit 6 Click 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 labeled 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.

This 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.

• Interface: GPIO, SPI
• Compatibility: mikroBUS™
• Dimensions: 42.9 x 25.4mm
• Input Voltage: 3.3V or 5V, External
• Supply Voltage VCC: Min. 3.3V, Max. 5V
• External Supply Voltage VIN: Min. 4.5V, Max. 60V
• Output Current-Limit Range: Min. 0.1A, Max. 1A
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +125°C

• Schematic
• MAX17608 Datasheet
• MAX5401 Datasheet
• mikroSDK
• GitHub