2 Circuit Differences Between Channels

The LM5171 Channel 1 (CH1) and Channel 2 (CH2) have identical pinout but slightly different functions. Figure 2-1 shows the circuit differences between CH1 and CH2. The key differences are:

• DIR1 determines whether the HV error amplifier or LV error amplifier is active.
• When CH1 is inactive, VSET is pulled low.
• When OVP triggers, VSET and SS/DEM1 are pulled low.

When CH1 and CH2 are operated independently, CH1 has all the necessary features for a complete bidirectional converter: two error amplifiers for HV and LV rail voltage regulation, OVP with hysteresis, precise voltage reference with soft start. When operating CH2 in voltage mode, these features need to be implemented by external circuits.