ZHCSD14G October 2014 – March 2017 ISO7842
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 Pin Configuration and Functions
-
6 Specifications
- 6.1 Absolute Maximum Ratings
- 6.2 ESD Ratings
- 6.3 Recommended Operating Conditions
- 6.4 Thermal Information
- 6.5 Power Ratings
- 6.6 Insulation Specifications
- 6.7 Safety-Related Certifications
- 6.8 Safety Limiting Values
- 6.9 Electrical Characteristics-5-V Supply
- 6.10 Supply Current Characteristics-5-V Supply
- 6.11 Electrical Characteristics—3.3-V Supply
- 6.12 Supply Current Characteristics—3.3-V Supply
- 6.13 Electrical Characteristics—2.5-V Supply
- 6.14 Supply Current Characteristics—2.5-V Supply
- 6.15 Switching Characteristics—5-V Supply
- 6.16 Switching Characteristics—3.3-V Supply
- 6.17 Switching Characteristics—2.5-V Supply
- 6.18 Insulation Characteristics Curves
- 6.19 Typical Characteristics
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文档支持
- 13机械、封装和可订购信息
9 Application and Implementation
NOTE
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.
9.1 Application Information
The ISO7842 device is a high-performance, quad-channel digital isolator with a 5.7-kVRMS isolation voltage per UL 1577. The device comes with enable pins on each side that can be used to put the respective outputs in high impedance for multi-master driving applications and reduce power consumption. The ISO7842 device uses single-ended CMOS-logic switching technology. The supply voltage range is from 2.25 V to 5.5 V for both supplies, VCC1 and VCC2. When designing with digital isolators, keep in mind that because of 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.
9.2 Typical Application
Figure 18 shows the typical isolated RS-232 interface implementation.
Figure 18. Isolated RS-232 Interface
9.2.1 Design Requirements
For this design example, use the parameters shown in Table 3.
Table 3. Design Parameters
| PARAMETER | VALUE |
|---|---|
| Supply voltage | 2.25 to 5.5 V |
| Decoupling capacitor between VCC1 and GND1 | 0.1 µF |
| Decoupling capacitor from VCC2 and GND2 | 0.1 µF |
9.2.2 Detailed Design Procedure
Unlike optocouplers, which require external components to improve performance, provide bias, or limit current, the ISO7842 device only requires two external bypass capacitors to operate.
Figure 19. Typical ISO7842 Circuit Hook-Up
9.2.3 Application Curve
The typical eye diagram of the ISO7842 device indicates low jitter and wide open eye at the maximum data rate of 100 Mbps.
Figure 20. Eye Diagram at 100 Mbps PRBS, 5 V and 25°C