Isolated delta-sigma modulator for industrial automation

29th July 2020

Renesas

Lanna Deamer

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Datasheet

Renesas Electronics has announced the RV1S9353A optically isolated delta-sigma (ΔΣ) modulator. According to the company, the RV1S9353A delivers the industry’s highest accuracy compared to other 10MHz clock output optically isolated devices. It includes a precision analogue-to-digital converter with ENOB of 13.8 bits (typ) for converting an analogue voltage input into a digital output one-bit data stream across the isolation barrier.

The RV1S9353A connects directly to an RZ/T MPU and RX72M MCU, or other MPUs, MCUs, SoCs and FPGAs with a digital filter. The RV1S9353A is used in robotic arm controllers, as well as AC servo controllers and NC servo controllers employed in a range of smart factory equipment.

The trend toward improving control accuracy for industrial instruments is driving the demand for high accuracy optical isolation. Renesas’ RV1S9353A meets this need with precision sensing features, including lower offset voltage drift, higher Signal-to-Noise Ratio (SNR), lower reference voltage drift vs. temperature, and higher input resistance. The modulator’s low offset voltage drift simplifies offset correction and its 5kV rms isolation and 8mm creepage distance is ideal for compact 200V and 400V motor drive equipment.

OEMs want to standardise their designs during development and design certification. The RV1S9353A addresses this requirement with 500kΩ typical input resistance making it capable of both current sensing and voltage monitoring for easier design. Best of all, the ΔΣ modulator’s digital output and connected digital filter removes the need for complex multi-component designs that use a traditional analogue isolation amplifier with analog filter and several other components.

“The RV1S9353A ΔΣ modulator gives our customers the absolute highest accuracy and control needed to modernise today’s smart factories,” said Chris Stephens, Vice President of Communications & Motor Control, Industrial and Communications Business Division at Renesas. “Its higher input resistance and ability to provide both current sensing and voltage monitoring simplifies design and saves costs while meeting the UL, CSA and VDE safety standards.”

Key features of the RV1S9353A ΔΣ Modulator

Input offset voltage drift vs temperature (max) 2.5µV/°C
SNR (typ) 85dB
Reference voltage (max) gain error ±0.5%
Reference voltage drift vs. temperature (typ) 30ppm/°C
High input resistance (typ.) 500kΩ
High common mode transient immunity (typ) 25kV/us
Operating ambient temperature (max) -40°C to 110°C
Supplied in 8-pin SDIP with 1.27mm pin pitch

The new RV1S9353A ΔΣ modulator joins Renesas’ family of optoelectronic products, including photocouplers with IC output and high speed communication up to 15Mbps, as well as general-purpose transistor output devices featuring high isolation voltage, high temperature operation and compliance with various international safety standards. The motor driving photocouplers (IPM drive and IGBT drive) feature high isolation voltage, high temperature operation, high output current, and high speed switching.