SI8663ED-B-ISR

The Silicon Labs SI8663ED-B-ISR is an ultra-low-power 6-channel digital isolator using capacitive coupling technology. It offers substantial advantages over legacy optocoupler-based isolation in data rate, propagation delay, power consumption, size, reliability, and external BOM. The device supports data rates up to 150Mbps with less than 13ns propagation delay and 4.5ns pulse width distortion. The 5000Vrms isolation rating with reinforced insulation meets IEC 61010-1 and IEC 60950-1 safety requirements. The 3/3 channel configuration (3 forward, 3 reverse) is ideal for bidirectional communication interfaces like SPI and UART. Schmitt trigger inputs provide high noise immunity, and the selectable fail-safe mode controls output state during power loss.

The SI8663ED-B-ISR operates through capacitive coupling isolation: 1) Signal Transmission: High-speed digital signals are modulated and transmitted across on-chip silicon dioxide capacitors that provide the galvanic isolation barrier. The capacitors block DC and low-frequency common-mode voltages while passing the high-frequency modulated signal. 2) Demodulation: The receiving side demodulates the signal and reconstructs the original digital waveform with minimal propagation delay (10ns typ) and pulse width distortion (1.5ns typ). 3) Common-Mode Rejection: The capacitive coupling architecture provides inherent common-mode transient immunity of 35kV/us minimum, making the device suitable for noisy industrial environments. 4) Fail-Safe: When input power is lost, the outputs assume a predefined state (high or low, selected by ordering option) preventing undefined system behavior.

• Isolated SPI communication between MCU and high-voltage ADC
• Motor drive gate driver isolation with bidirectional fault signaling
• Industrial PLC digital I/O channel isolation