ZHCS455F December 2010 – July 2015 ISO7420E , ISO7420FE , ISO7421E , ISO7421FE
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 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 Electrical Characteristics: VCC1 and VCC2 = 5 V ± 10%
- 6.6 Electrical Characteristics: VCC1 = 5 V ± 10%, VCC2 = 3.3 V ± 10%
- 6.7 Electrical Characteristics: VCC1 = 3.3 V ± 10%, VCC2 = 5 V ± 10%
- 6.8 Electrical Characteristics: VCC1 and VCC2 = 3.3 V ± 10%
- 6.9 Power Dissipation Characteristics
- 6.10 Switching Characteristics: VCC1 and VCC2 = 5 V ± 10%
- 6.11 Switching Characteristics: VCC1 = 5 V ± 10%, VCC2 = 3.3 V ± 10%
- 6.12 Switching Characteristics: VCC1 = 3.3 V ± 10%, VCC2 = 5 V ± 10%
- 6.13 Switching Characteristics: VCC1 and VCC2 = 3.3 V ± 10%
- 6.14 Typical Characteristics
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Applications and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
9 Applications 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
ISO742x utilize single-ended TTL-logic switching technology. Its supply voltage range is from 3 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 (i.e. μC or UART), and a data converter or a line transceiver, regardless of the interface type or standard.
9.2 Typical Application
ISO7421 can be used with Texas Instruments' mixed signal micro-controller, digital-to-analog converter, transformer driver, and voltage regulator to create an isolated 4-20 mA current loop.
Figure 23. Isolated 4-20 mA Current Loop
9.2.1 Design Requirements
Unlike optocouplers, which require external components to improve performance, provide bias, or limit current, the ISO742x only require two external bypass capacitors to operate.
9.2.2 Detailed Design Procedure
9.2.2.1 Maximum Supply Current Equations
(Calculated over recommended operating temperature range and Silicon process variation)
9.2.2.1.1 ISO7420
At VCC1 = VCC2 = 3.3V ± 10%
At VCC1 = VCC2 = 5V ± 10%
9.2.2.1.2 ISO7421
At VCC1 = VCC2 = 3.3V ± 10%
At VCC1 = VCC2 = 5V ± 10%
ICC1_Q (max) and ICC2_Q (max) are equivalent to the maximum supply currents measured in mA under DC input conditions (provided in the specification tables of this data sheet); f is data rate in Mbps of both channels; CL is the capacitive load in pF of both channels. ICC1(max) and ICC2(max) are measured in mA.
9.2.2.2 Typical Supply Current Equations:
(Calculated over recommended operating temperature range and Silicon process variation)
9.2.2.2.1 ISO7420
At VCC1 = VCC2 = 3.3V
At VCC1 = VCC2 = 5V
9.2.2.2.2 ISO7421
At VCC1 = VCC2 = 3.3V
At VCC1 = VCC2 = 5V
ICC1_Q (typ) and ICC2_Q (typ) are equivalent to the typical supply currents measured in mA under DC input conditions (provided in the specification tables of this data sheet); f is data rate in Mbps of each channel; CL is the capacitive load in pF of each channel. ICC1(typ) and ICC2(typ) are measured in mA.
Figure 24. Typical ISO7420 Circuit Hookup
Figure 25. Typical ISO7421 Circuit Hookup
9.2.3 Application Curves
Figure 26. ISO7420FE Typical Eye Diagram at 50 MBPS, 3.3 V Operation
Figure 27. ISO7420FE Typical Eye Diagram at 100 MBPS, 3.3 V Operation