The ISO7520C and ISO7521C provide galvanic isolation of up to 4243 VRMS for 1 minute per UL and 6000 VPK per VDE. These devices are also certified to 5000 VRMS reinforced insulation per end equipment standards IEC 60950-1, IEC 61010-1, and IEC 60601-1. These digital isolators have two isolated channels with unidirectional (ISO7520C) and bidirectional (ISO7521C) channel configurations. Each isolation channel has a logic input and output buffer separated by a silicon oxide (SiO2) insulation barrier. Used in conjunction with isolated power supplies, these devices prevent noise currents on a data bus or other circuits from entering the local ground and interfering with or damaging sensitive circuitry. The devices have TTL input thresholds and can operate from 3.3- and 5-V supplies. All inputs are 5-V tolerant when supplied from 3.3-V supplies. NOTE: The ISO7520C and ISO7521C are specified for signaling rates up to 1 Mbps. Due to their fast response time, these devices will also transmit faster data with much shorter pulse widths. Designers must add external filtering to remove spurious signals with input pulse duration < 20 ns, if desired.