LT8418 Vcc UVLO timing sequence

Hello,

I test LT8418 in PCB board for motor driver.

At the moment the motor operates, the input voltage of the LT8418 momentarily rises above 6V or drops below 3.5V.

What should be the maximum timing sequence (in microseconds) for UVLO and OVLO triggers to prevent protection from occurring?

1. Vcc (Ch3, Red) Voltage Fluctuation 

• Maximum voltage: 5.887V → Potential OVLO trigger
• Minimum voltage: 4.141V → Potential UVLO trigger
• Average voltage: 5.085V → Normal level
• Peak-to-peak variation: 1.746V → Excessive voltage fluctuation detected

2. Supply Current (Ch4, Green)

• Severe current fluctuation observed, with high-amplitude switching ripple (approx. 184.4mA average).
• Sudden current draw from the motor results in both a voltage drop (4.1V) and excessive voltage rise (5.88V).

3. TG (Ch2, Blue) / BG (Ch1, Yellow) PWM Signal Analysis

• PWM waveform intermittently breaks in an irregular pattern.
• This indicates that UVLO/OVLO protection has been activated, disabling PWM output.