Hi,
I'm using a external supply to activate the TPS65400 of my customer. The circuit is like that :
At first Q2 short-circuit the pin CHIP_ENABLE and when the threshold is reached Q1 short-circuit Q2 and the voltage around the pin CHIP_ENABLE is released.
The voltage should be around 4.5V which is under the limitation of 7.2V.
But here is a scope of a test with a freezing spray on the Under Voltage Lockout function above :
BLUE : V_CHIP_ENABLE
PURPLE : VDDA
CYAN : VOUT (The voltage which is use for my resistor divider)
GREEN : VOUT_PMIC
I retry without the spray :
The voltage around the pin CE was 11.7 V !?
Do you have an idea about this problem ?
My TPS65400 is powered with 12V (the same voltage as my resistor divider).
