SI840XI2C-KIT Silicon Laboratories Inc, SI840XI2C-KIT Datasheet - Page 12

• Manufacturer Part Number: SI840XI2C-KIT
• Description: KIT EVAL FOR SI840X
• Manufacturer: Silicon Laboratories Inc

Specifications of SI840XI2C-KIT

• Main Purpose: Interface, Digital Isolator
• Embedded: No
• Utilized Ic / Part: Si8400, Si8401, Si8405
• Primary Attributes: Assorted Bi-directional i²C Isolators
• Secondary Attributes: 2 Single Channel, 1 Dual channel isolator
• Interface Type: I2C
• Operating Supply Voltage: 2.7 V to 5.5 V
• Product: Interface Modules
• For Use With/related Products: Si840x
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 336-1990

Si840x
2. Functional Description
2.1. Theory of Operation
The operation of an Si84xx 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 unidirectional Si84xx channel is
shown in Figure 5.
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 6 for more details.
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A
Transmitter
OSCILLATOR
MODULATOR
Figure 5. Simplified Channel Diagram
RF
Figure 6. Modulation Scheme
Semiconductor-
Based Isolation
Rev. 1.3
Barrier
DEMODULATOR
Modulation Signal
Output Signal
Input Signal
Receiver
B