Ensure stable and safe operation of various systems with MIC33153 and PIC18F57Q43

MIC33153 Click is based on the MIC33153, a 4MHz DC-DC buck regulator with integrated inductor and Hyperlight Load™ technology, from Microchip. This integrated buck regulator requires minimal external components, including the inductor. This simplifies the design greatly, retaining the advertised electrical characteristics. Also, thermal shutdown and current limit protection features ensure safe operation, even in case of errors and short circuits. This Click operates with an input voltage range from 2.7V up to 5.5V, and it can deliver a regulated output ranging from 0.8V to 3.5V, with up to 1.2A. The output voltage is selectable, and the voltage on the FB pin manages it. This pin is routed to the output of the MCP4921, a 12-bit DAC converter from Microchip, with the SPI interface. The voltage on the DAC output affects the FB pin voltage, which in turn affects the main output voltage. A voltage divider connected between the main output terminal and the GND allows monitoring of the output voltage via the AN pin of the mikroBUS™. This gives an insight into the output voltage condition: if the output voltage deviates from the desired value, the corrected value can be sent to the DAC. MCP4921 DAC converter has its SPI lines routed to the mikroBUS™, so it is enough to send a new value via the SPI of the click board™ if a correction is needed. Of course, being a buck converter,

the Click board™ expects higher input voltage than it is set at its output. The proprietary HyperLight Load™ technology allows it to operate efficiently when a very light load is connected to the output terminal. Instead of using the continuous PWM signal to operate the DC-DC buck converter, it goes into the discontinuous mode, with the pulse frequency modulation (PFM) signal used for regulating the output. As the output current rises, the device enters the continuous conducting mode (CCM) with the PWM frequency at 4MHz. The transition is transparent and happens automatically when the output current rises above a certain level. This level depends on the duty cycle of the internal PWM signal, input and output voltages, PWM frequency, and the internal coil inductance, and it is about 200mA for the VIN = 3.6V and VOUT = 1.8V. The EN pin of the MIC33153 is also routed to the mikroBUS™, and it is used to turn off the output stage of the DC-DC step-down converter. A logic HIGH signal will activate the device, while the logic LOW will put the device in shutdown mode with very low power consumption. The EN pin is subject to a soft start circuitry that reduces the inrush current and prevents the output voltage from overshooting at the start-up. The Soft start delay is determined by the capacitor connected to the SS pin, which is fixed to around 300µS for the

MIC33153 Click. The EN pin is pulled HIGH by the onboard resistor. The PG pin of the MIC33153 is routed to the INT pin of the mikroBUS™, and it is used to signalize the power good status of the output voltage. An open drain output is pulled low when the output voltage drops under 86%. It reverts to the HIGH logic state when the output voltage reaches 92% of its steady state. It can generate the interrupt event on the controller or otherwise signal the output voltage problem. The PG pin is pulled HIGH by the onboard resistor. The MIC33153 click has two robust screw terminals connecting the input and output voltage rails. Instead of the input terminal, the click can use the voltage input from the development system if the VIN SEL SMD jumper is switched to the VCC position (default jumper position). MIC33153 click can work with both 3.3V and 5V rated MCUs. The VCC SEL SMD jumper should be switched to the correct position, indicated by the label - 3.3V or 5V, to select the desired operational voltage. It should be noted that the selected voltage will be used as the internal voltage supply for the buck converter input if selected so by the VIN SEL. Also, 3.3V is required regardless of the position of the VCC SEL jumper since the MCP4921 DAC is powered up from the 3.3V rail directly.

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.