9 Parameter Measurement Information

In this section, GND1 = GNDIO, GND2 = GISOIN unless otherwise noted.

Figure 9-1 Driver Voltages

R_L = 100 Ω for RS-422, R_L = 54 Ω for RS-485

Figure 9-2 Driver Voltages

C_L includes fixture and instrumentation capacitance

Figure 9-3 Driver Switching Specifications

Includes probe and fixture capacitance

Pass-fail criteria: Device is tested in both half-duplex and full-duplex conditions. Both the signal path and power path should be in specification compliant region during the application of CMTI pulse. This means no bit flips on R, and both V_ISOOUT and Driver V_OD should be within specifications mentioned in electrical characterisitcs table.

Figure 9-4 Common Mode Transient Immunity (CMTI)—Full Duplex

C_L includes fixture and instrumentation capacitance

Figure 9-5 Driver Enable and Disable Times

Figure 9-6 Driver Enable and Disable Times

C_L includes fixture and instrumentation capacitance

Figure 9-7 Receiver Switching Specifications

Figure 9-8 Receiver Enable and Disable Times

Figure 9-9 Receiver Enable and Disable Times

The driver should not sustain any damage with this configuration

Figure 9-10 Short-Circuit Current Limiting

The input pulse is supplied by a generator having the following characteristics: PRR ≤ 50 kHz, 50% duty cycle, t_r ≤ 3 ns, t_f ≤ 3 ns, Z_O = 50 Ω. At the input, 50-Ω resistor is required to terminate the input generator signal. The resistor is not required in the actual application. C_L = 15 pF and includes instrumentation and fixture capacitance within ±20%.

Figure 9-11 GPIO Channel: Switching Characteristics Test Circuit and Voltage Waveforms