JAJSF96C April 2018 – October 2021 LM5036
PRODUCTION DATA
An example implementation of the VAUX2 level-shift detection circuit is shown in Figure 8-3. The zener voltage must be between the off-state and on-state level of VAUX2. When VAUX2 is above the zener voltage, both Q1A and Q1B are turned on and therefore the reference output voltage VREFSec is clamped to ground. Once VAUX2 falls below the zener voltage, both Q1A and Q1B are turned off, and the reference is released.
Designers who wish to benefit from the fully regulated pre-biased startup feature of LM5036 must use separate voltage reference and error amplifier devices. Popular combined error amplifier and voltage reference devices, such as TL431, can be used only when the fully regulated pre-biased startup feature is not required.
Assistance with half-bridge voltage control loop design may be obtained using the Power Stage Designer™ tool.