The ISO7421-EP device provides galvanic isolation up to 2500 VRMS
for 1 minute per UL. The ISO7421-EP device has two isolated channels. Each isolation channel has a
logic input and output buffer separated by a silicon dioxide (SiO2)
insulation barrier. Used in conjunction with isolated power supplies, the device prevents noise
currents on a data bus or other circuit from entering the local ground and interfering with or
damaging sensitive circuitry.
This device have TTL input thresholds and require two supply voltages, 3.3 or 5 V, or any
combination. All inputs are 5-V tolerant when supplied from a 3.3-V supply.
The ISO7421-EP device is specified for signaling rates up to 1 Mbps. Due to its fast
response time, under most cases, this device will also transmit data with much shorter pulse
widths. Designers should add external filtering to remove spurious signals with input pulse
duration <20 ns if desired.