The ISO7631F and ISO7641F devices provide galvanic isolation up to 4242 VPK per VDE. The ISO7631F device has three channels, two of which operate in the forward direction and one which operates in the reverse direction. The ISO7641F device has 4 channels, three of which operate in the forward direction and one of which operates in the reverse direction. Suffix F indicates that output defaults to low-state in fail-safe conditions (see ). M-Grade devices are high-speed isolators capable of up to150-Mbps data rates with fast propagation delays, whereas C-Grade devices are capable of up to 25-Mbps data rates with low power consumption and integrated filters for noise-prone applications. C-Grade devices are recommended for lower-speed applications where input noise pulses of less than 6 ns duration must be suppressed, or when low-power consumption is critical. 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, 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 2.7-V (M-Grade), 3.3-V and 5-V supplies. All inputs are 5-V tolerant when supplied from 3.3-V or 2.7-V supplies.