Power inverters in solar photovoltaic systems are often connected directly to the electricity grid in order to inject the created energy into the mains and act as an electricity supplier. This energy must comply with certain regulations that set the standard in terms of quality and safety which requires of accurate measurements.
The AS8002 is a highly accurate measurement IC that allows monitoring the generated energy with low cost shunt resistors or other sensors for the current and resistor dividers for the voltage. This approach allows avoiding more expensive sensing devices while achieving the required accuracy for DC and AC measurements of current and voltage as well as stability over the operating temperature range of the inverter.
The 12 bit ADC samples the voltage and current and provides their instantaneous values through an SPI interface.
The 12 Bit ADC is preceded by low noise programmable gain amplifiers in order to accommodate different sensors. The ADC has three multiplexed inputs, offering one secondary channel in addition to the main voltage and current.
The on-chip temperature sensor provides the inverter designer the option of temperature compensation for any of the measured parameters or functional blocks provided, over the full operating temperature range of the device.
The on-chip voltage reference is connected to the ADC and to REF. An external crystal oscillator is not required as a high accuracy internal oscillator clock is available.
The independent over current interrupt detects a high current on the grid and allows the processor to open the switches without waiting for the ADC conversion.
The AS8002 Adapter Board
The AS8002-AB-1.0 Adapter board allows you an easy-to-use evaluation of the essential functions of the AS8002. It is a system with built-in microcontroller, USB interface and a simple analogue frontend. The complete system is fully supplied by the PC and needs no additional external power supply.