Novosense – SP301L/H: RS485 Isolation: Novosense develops analog and mixed-signal semiconductors for demanding industrial, energy, and automotive applications.
By 2025, Novosense had shipped more than 2.7 billion ICs featuring its in-house developed capacitive isolation technology.
For further background, the manufacturer provides an informative YouTube video covering the fundamentals of digital isolation.
The SP301L and SP301H are three-channel digital isolators for galvanically isolated RS485 interfaces. Available in the SSOW10 package, they combine two forward channels. One for data and the other acts as driver enable. The last one is the reverse channel for the receive signal.
This enables a microcontroller to be directly and compactly isolated from an RS485 transceiver on the isolated field side. According to Novosense, using the SP301L/H ICs can reduce PCB area requirements by up to 60% compared with an implementation using three conventional optocouplers.
The two variants support different default voltage level (off state) at the enable pin: L for “default low” and H for “default high”. Both versions provide a defined output state if the input-side supply voltage is lost.
The devices support data rates from DC to 8 Mbit/s and supply voltages from 2.5 V to 5.5 V on both sides of the isolation barrier. This makes them suitable for both 3.3 V and 5 V designs while also simplifying logic-level translation.
The specified operating temperature range extends from −40 to +125 °C.
For harsh environments, the SP301L/H offer a typical CMTI of ±200 kV/µs, ±8 kV HBM ESD robustness, and a maximum surge isolation voltage of 10 kV peak.
Their isolation withstand rating according to UL 1577 is 5 kVRMS for one minute. In addition, NOVOSENSE specifies reinforced isolation in accordance with DIN EN IEC 60747-17, with a maximum working isolation voltage of 1500 VRMS AC or 2121 VDC.
Typical applications include isolated RS485 nodes in industrial automation, energy systems, smart-grid infrastructure, and smart-metering equipment. Here the use eases especially where differing ground potentials, fast common-mode transients, or stringent EMC requirements stress the communication interface.
Are you planning a robust, standards-compliant RS485 interface? Contact us directly, for support with component selection and sourcing. In addition to the Novosense SP301L/H RS485 isolators, we are happy to advise you on further components for your application.