SI8621BD-B-IS Silicon Laboratories Inc, SI8621BD-B-IS Datasheet - Page 18

• Manufacturer Part Number: SI8621BD-B-IS
• Description: IC ISOLATOR 2CH 5KV 16SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI8621BD-B-IS

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-2065-5

Si8610/20/21/22
2. Functional Description
2.1. Theory of Operation
The operation of an Si861x/2x channel is analogous to that of an opto coupler, except an RF carrier is modulated
instead of light. This simple architecture provides a robust isolated data path and requires no special
considerations or initialization at start-up. A simplified block diagram for a single Si861x/2x channel is shown in
Figure 4.
A channel consists of an RF Transmitter and RF Receiver separated by a semiconductor-based isolation barrier.
Referring to the Transmitter, input A modulates the carrier provided by an RF oscillator using on/off keying. The
Receiver contains a demodulator that decodes the input state according to its RF energy content and applies the
result to output B via the output driver. This RF on/off keying scheme is superior to pulse code schemes as it
provides best-in-class noise immunity, low power consumption, and better immunity to magnetic fields. See
Figure 5 for more details.
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A
Transmitter
OSCILLATOR
MODULATOR
Figure 4. Simplified Channel Diagram
RF
Figure 5. Modulation Scheme
Semiconductor-
Based Isolation
Rev. 1.3
Barrier
DEMODULATOR
Modulation Signal
Output Signal
Input Signal
Receiver
B