Single-channel digital isolator for industrial interface lanes
The Renesas PS9851-1-F3-AX is a single-channel, DC-input optocoupler from the NEPOC series with a push-pull / totem-pole output. It is built for isolating digital signals in industrial communication buses — CAN, RS-485, SPI — where 15 Mbps data rate and 2500 Vrms isolation cover the typical line speed and safety barrier requirements. The output type means it can drive a logic gate input directly without an external pull-up, simplifying the receiver side of the isolation channel. The 10 kV/µs common-mode transient immunity (CMTI) rating is the spec that matters when the part sits across a motor-drive or inverter isolation boundary: fast voltage transients from the switching node are suppressed enough to avoid bit errors on the data line.
60 ns propagation delay — timing budget for the bus
Maximum propagation delay of 60 ns (tpLH / tpHL) sets the timing budget for a closed-loop control loop or a polled SPI transaction. In a 1 MHz SPI link running at 15 Mbps, the 60 ns delay adds roughly one bit-time of latency per isolation crossing — acceptable for most sensor-to-controller links, but something to verify against the system's worst-case jitter budget. Rise and fall times are both 4 ns typical, giving clean edges that keep signal-integrity reflections low on short board traces inside the same enclosure.
ROHS3 compliant per the listing, which matches current European and Asian assembly requirements. For dual-sourcing or higher channel count, the NEPOC family includes the two-channel PS9851-2-F3-AX and PS9851-2-V-F3-AX variants with identical 15 Mbps speed, 60 ns propagation delay, and same 8-SOIC footprint — useful if a board spin adds a second isolated channel.
Supply rail and drive current
Each channel delivers 2 mA output current, enough to drive one CMOS load or a high-impedance ADC input; for heavier loads (opto-MOSFET gate, long cable), buffer externally. Forward voltage is 1.6 V typical at the LED input, with a maximum DC forward current of 20 mA. The 1.6 V Vf is compatible with 3.3 V logic if a series resistor limits the LED current to the 20 mA ceiling.
Package and temperature grade
Housed in an 8-SOIC (3.90 mm width) package, also referred to as 8-SSOP in the supplier device package field. Surface-mount, compatible with standard reflow profiles.