9.1 Application Information

ISO764x use single-ended TTL-logic switching technology. Its supply voltage range is from 3 V to 5.5 V for both supplies, V_CC1 and V_CC2. When designing with digital isolators, it is important to note 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.

9.2 Typical Application

Figure 16. Isolated Data Acquisition System for Process Control

9.2.2 Detailed Design Procedure

Figure 17. Typical ISO7640FM Circuit Hookup

Figure 18. Typical ISO7641FM Circuit Hookup

9.2.2.1 Typical Supply Current Equations

(Calculated based on room temperature and typical Silicon process)

ISO7640FM:

At V_CC1 = V_CC2 = 3.3 V

Equation 1. I_CC1 = 0.388 + 0.0312 × f

Equation 2. I_CC2 = 3.39 + 0.03561 × f + 0.006588 × f × C_L

At V_CC1 = V_CC2 = 5 V

Equation 3. I_CC1 = 0.584 + 0.05349 × f

Equation 4. I_CC2 = 4.184 + 0.05597 × f + 0.009771 × f × C_L

ISO7641FM:

At V_CC1 = V_CC2 = 3.3 V

Equation 5. I_CC1 = 1.848 + 0.03233 × f + 0.001645 × f × C_L

Equation 6. I_CC2 = 3.005 + 0.03459 x f + 0.0049395 × f × C_L

At V_CC1 = V_CC2 = 5 V

Equation 7. I_CC1 = 2.369 + 0.05385 × f + 0.002448 × f × C_L

Equation 8. I_CC2 = 3.857 + 0.05506 × f + 0.007348 × f × C_L

I_CC1 and I_CC2 are typical supply currents measured in mA; f is data rate measured in Mbps; C_L is the capacitive load on each channel measured in pF.

9.2.3 Application Curves

Figure 19. Typical Eye Diagram at 150 Mbps,
5-V Operation

Figure 20. Typical Eye Diagram at 150 Mbps,
3.3-V Operation