STMicroelectronics introduces two highly integrated electrically isolated Sigma-Delta modulators

     The STMicroelectronics ISOSD61 and ISOSD61L are high-precision isolated second-order sigma-delta modulators that improve the performance and reliability of industrial applications such as motor control, electric vehicle charging stations, solar inverters, UPS power supplies, and server and telecommunications power supplies.

     The ISOSD61 has TTL/CMOS compatible clock input and data output signal levels, while the ISOSD61L is compatible with low-voltage differential signals (LVDS). Both models have a 16-bit ADC resolution and a typical signal-to-noise ratio (SNR) of 86dB.

     The internal electrical isolation technology of both products completely eliminates the performance degradation caused by the use of optocoupling isolation, while also reducing power consumption and improving data transfer rates. The new product converts analog input signals of up to ±320mV to high-speed 1-bit digital data streams of up to 25Msamples /s. Under normal conditions, the input and output isolation capacity can be up to 6kV maximum transient voltage and surge isolation voltage, the maximum operating voltage is up to 1.2kV, and the common mode transient immunity is 30kV/μs, which can excellent suppression of rapid transient noise common in harsh industrial environments.

     Thanks to the external 25MHz sampling frequency, these modulators are suitable for handling very wide bandwidth input signals, with excellent high frequency signal processing capabilities and measurement accuracy, preparing the latest inverters and fast switches based on advanced power technologies such as silicon carbide (SiC) in high-resolution motor control systems.

     By integrating ADC and isolated UART peripherals on a single chip, the ISOSD61 and ISOSD61L help reduce bill of material costs, improve noise resistance and reliability, and reduce the overall cost of the end application. Separate current detection sensors are not required because a smaller current sampling resistor chip can be used.

     Both products are packaged in SO16W surface-mount plastic to meet the requirements of 8mm creepage distance and electrical clearance, and the operating temperature range is industrial-grade -40°C to +125°C.Both fully functional evaluation boards are available now. The ISOSD61 EVALST-ISOSD61T and ISOSD61L EVALST-ISOSD61L provide input and output coaxial cable interfaces and pin sockets, as well as pads for mounting current sampling sensors.