The first test assesses each device’s peak performance with a minimal capacitive load. By limiting the output load to only 15 pF, the user can measure the typical maximum capability of each translator. See Figure 3-1 for the test setup.

Figure 3-1 Light Capacitive Load Bench Setup, 1.2V to 1.8V

Figure 3-2 TXB0104, 1.2V to 1.8V, Output Cload = 15pF, 60MHz

Figure 3-3 TXB0604, 1.2V to 1.8V, Output Cload = 15pF, 60MHz

With both devices provided the same input signal, the TXB0104 (Figure 3-2) is unable to support the 60MHz / 120Mbps signal—data bits are skipped because the signal exceeds the maximum supported data rate of the device. The TXB0604, however, can handle the 60MHz signal without issue. At higher VCC, the TXB0604 is able to achieve 80MHz+ as shown in the setup and waveform.

Figure 3-4 Light Capacitive Load Bench Setup, 1.8V to 3.3V

Figure 3-5 TXB0604, 1.8V to 3.3V, Output Cload = 15pF, 80MHz

The waveform above captures the signal integrity of the TXB0604 operating at a high data rate under a small capacitive loading condition.