For proper operation, V_CCA must always be at least 0.8 V less than V_CCB (V_CCA + 0.8 ≦ V_CCB). The 200 kΩ bias resistor is required to allow V_{ref_B} to regulate the EN input and properly bias the device for translation. A 0.1 µF capacitor is recommended for providing a path from V_{ref_B} to ground for high frequency noise. V_{ref_B} and V_I(EN) are recommended to be 1.0 V higher than V_{ref_A} for best signal integrity.

Attempting to drive the EN pin directly with a push-pull output device is a very common design error with the LSF0102-Q1 series of devices. It is also very important to note that current does flow into the A-side voltage supply during normal operation. Not all voltage sources can sink current, so be sure that applicable designs can handle this current. For more design details, see the Understanding the Bias Circuit for the LSF Family video.

Figure 9-2 Bias Circuitry Inside the LSF010x-Q1 Device