SLLSEP0A July 2015 – March 2016 ISO7820
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The ISO7820 is a high-performance, dual-channel digital isolator with 5.7 kVRMS isolation voltage per UL 1577. It utilizes single-ended CMOS-logic switching technology. Its supply voltage range is from 2.25 V to 5.5 V for both supplies, VCC1 and VCC2. When designing with digital isolators, it is important to keep in mind that due to the single-ended design structure, digital isolators do not conform to any specific interface standard and are only intended for isolating single-ended CMOS or TTL digital signal lines. The isolator is typically placed between the data controller (that is, μC or UART), and a data converter or a line transceiver, regardless of the interface type or standard.
For the ISO7820, use the parameters shown in Table 7.
|Supply voltage||2.25 V to 5.5 V|
|Decoupling capacitor between VCC1 and GND1||0.1 µF|
|Decoupling capacitor from VCC2 and GND2||0.1 µF|
Unlike optocouplers, which need external components to improve performance, provide bias, or limit current, ISO7820 only needs two external bypass capacitors to operate.
Many applications in harsh industrial environment are sensitive to disturbances such as electrostatic discharge (ESD), electrical fast transient (EFT), surge and electromagnetic emissions. These electromagnetic disturbances are regulated by international standards such as IEC 61000-4-x and CISPR 22. Although system-level performance and reliability depends, to a large extent, on the application board design and layout, the ISO7820 incorporate many chip-level design improvements for overall system robustness. Some of these improvements include:
Typical eye diagram of ISO7820 indicate low jitter and wide open eye at the maximum data rate of 100 Mbps.