HOW DOES IT WORK?

PAC1720 Click as its foundation uses the PAC1720, a dual bidirectional high-side current-sensing device with precision voltage measurement capabilities from Microchip Technology. It measures the voltage developed across external sense resistors to represent the high-side current of a battery or voltage regulator, then digitizes it with a variable resolution Sigma-Delta ADC and transmits it over the I2C protocol. The PAC1720 also measures the SENSE+ pin voltages and calculates average power over the integration period.

The PAC1720 has three states of operation: Active, Standby, and One-Shot Mode. In Active mode, the PAC1720 initiates conversion cycles for the programmed conversion rate. The Standby mode represents the lowest power state, where there are no conversion cycles. The majority of circuitry is powered-down to reduce supply current to a minimum. While the device is in the Standby state, the host can initiate a conversion cycle on-demand using One-Shot mode. After the conversion cycle is complete, the device will return to the Standby state.

PAC1720 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting operation with a clock frequency up to 400kHz. Besides, it also allows the choice of its I2C slave address by positioning the SMD resistor of appropriate value labeled as R2, giving the user the ability to select one of eight possible slave addresses.

The current range allows for significant variations in measured current with high accuracy and the low voltage drop across the resistor. The PAC1720 has programmable high and low limits for current sense and bus voltage with a maskable alert signal labeled as INT, routed to the RST pin of the mikroBUS™ socket, to the host when an out-of-limit measurement occurs.

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 I2C 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