Other Parts Discussed in Thread: TL7700, UC1903, TPS386000
Hi, team.
I received a question from the customer "Can we respond to negative voltage monitoring on TPS3808?"
(The customer is considering of two ways.)
Can you tell me if it can be used?
(1) Connect the VDD pin to GND(0V),Connect the GND pin to the negative power supply(-5.0V).
Input to the SENSE pin is a value obtained by dividing GND negative power supply (about -4.5V:voltage value higher than the threshold value).
(The input voltage to the SENSE pin goes low as the negative power supply voltage drops)
Since GND is output to the output pin (RESET) at H and a negative power supply is output at L.
Received by a photocoupler or an operational amplifier, it is converted to the logic of the positive power supply and connected to the latter stage circuit.
This circuit is a track record using of TL7700 before.
(TL7700 can not be used because the board of this time is 105 ℃ specification)
(2) VDD pin connects positive power supply(5V) and GND pin to GND(0V).
For the SENSE pin, input a value obtained by dividing a positive power supply to a negative power supply (a voltage value lower than the threshold value).
When the negative supply causes a voltage drop, the input voltage to the SENSE pin goes high.
Since the output pin (RESET) becomes a logic inversion, connect the inverter to the subsequent stage circuit.
Best regards,
Masumi Sekiguchi.