Critical AFE IP block converts current to voltage

Providing direct interface to the sensor systems with current output, the SCi310 is suited for applications including bio industry, medical, environmental, agriculture, aquaculture, food, ecology (soil, air and water pollution monitoring), photonics, energy and process control (smart meters and grids), instrumentation, automotive and security, military equipment and aircraft, mobile phones and gadgets and PCs and laptops with built-in sensors. The SCi310 is suitable for ASICs which are used in a large variety of applications - optical systems, pollution-detectors and monitoring, water treatment and processing, HVAC engineering industries, amperometric applications, chemical species identification, car engine control systems, navigation systems, precision process control, electrochemical blood glucose meter, X-ray detection systems, CT scanners or generally anywhere where photodiode sensors are being used, etc.

Using a proprietary Transimpendance Amplifier architecture with eight digitally programmable current ranges (from 8uA-1mA), the SCi310 converts current captured from the sensor system to a fully differential output voltage, ready to be amplified. The block can be connected to a wide variety of sensors with varying full scale current outputs. With voltages being more convenient for signal processing than currents, it makes sense to employ the functionality of a current-to-voltage converter prior any further analogue signal processing. The SCi310 maintains the constant voltage at the input pin for all operating modes and input currents, this is particularly useful when biasing PiN diodes in photoconductive region (preferred over photovoltaic region because of its linearity).

Designed to enhance linearity, the IP block keeps the offset low using a specially designed Auto Zeroing offset cancellation circuit that is applied via a digital signal.With this, any resulting output voltage in Auto Zero mode can be later used in the signal path for compensation. Particularly useful for the cancellation of offset coming from the sensor, a positive or negative current can be applied to the Ioc pin from an external variable current source such as a current DAC to cancel positive or negative offset voltages at the output.

Measuring absolute input current values over seven orders of magnitude (picoA to milliA), the SCi310 can detect and measure a small input current difference with additional switched-capacitor circuit for generating signal difference and amplification. The IP can be easily modified to accommodate customisable current ranges on demand and it can also be upgraded for multi-channel inputs, etc.

Damir Vuk , CEO and Co-founder of Systemcom, comments: "Although the SCi310 design has been silicon proven in TSMC 0.18um. We can help JVD to port the technology to other foundries to meet their customer's expectations. The SCi310 is developed by the Systemcom Ltd. team and now is available for integration into JVD Analog ASICs thanks to the relationship between JVD and Systemcom announced in 2013.”