15 Mbps push-pull isolator for industrial digital buses
The Renesas PS9123-F3-AX is a single-channel digital optocoupler with a push-pull, totem-pole output stage rated for 15 Mbps data rates.
What the 60 ns propagation delay means for timing closure
The maximum propagation delay of 60 ns for both tpLH and tpHL sets a 120 ns round-trip budget in isolated feedback loops like those in flyback or LLC converters. The nominal is tighter, but the absolute-maximum table is where the design lives — page 7 of the datasheet carries the min/max columns.
Supply rail and logic compatibility
For 3.3 V systems, this part will not drive a 3.3 V CMOS input directly without a voltage divider or level shifter — the output high is essentially VCC, so feeding 5 V into a 3.3 V-tolerant pin exceeds the absolute maximum. The input LED forward voltage is 1.55 V typical, driven by a maximum 20 mA DC forward current.
Package and footprint notes
Housed in a 5-lead 6-SOIC (0.173", 4.40 mm width) surface-mount package, supplier device package 5-SO. The 5-lead variant saves board area compared to an 8-pin DIP while keeping the 3750 Vrms creepage. MSL 3 out of the bag — bake before reflow if the moisture-barrier bag has been open past the floor-life window.