si8235 Silicon Laboratories, si8235 Datasheet - Page 12

• Manufacturer Part Number: si8235
• Description: 0.5 And 4.0 A Isodrivers
• Manufacturer: Silicon Laboratories

Si823x
4. Overview
The Si823x ISOdrivers are dual output drivers for isolated high-side/low-side and dual low-side gate drive
applications. These products utilize Silicon Laboratories' proprietary silicon isolator technology, which enables fast
propagation time while withstanding 600 V dc from the input to either output and between outputs. The operation of
this isolator is analogous to that of an optocoupler, except that 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. As shown in Figure 6, an isolation channel consists of an RF transmitter and receiver separated by an RF
transformer.
TRANSMITTER
RF
OSCILLATOR
RECEIVER
RF
Transformer
A
DEMODULATOR
B
MODULATOR
Figure 6. Isolator Operation
Input "A" turns the RF carrier on when high and off when low. The carrier is transmitted through the RF transformer
to the output side demodulator, which consists of a receiver tuned to the carrier frequency. The demodulator
asserts output "B" when sufficient in-band energy is detected. The driver output stage follows that of output B.
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