SLVSFM0C September 2020 – January 2024 TPS3899
PRODUCTION DATA
The TPS3899 voltage supervisor with push-button monitor asserts a RESET/RESET signal when the SENSE pin voltage drops below VIT- for the duration of the sense delay set by CTS. If the SENSE pin voltage rises above VIT- + VHYS before the sense delay expires, the RESET/RESET pin does not assert. When asserted, the RESET/RESET output remains asserted until SENSE voltage returns above VIT- + VHYS for the duration of the reset delay set by CTR. If the SENSE pin voltage falls below VIT- before the reset delay expires while RESET is asserted, RESET/RESET will remain asserted.
Like most voltage supervisors, the
TPS3899 includes a reset delay tD to provide time for the power and
clocks to settle before letting the processor out of reset. At power up, the
circuits inside the TPS3899 need additional time to start the reset delay timer
after its power supply VDD has reached minimum VDD(MIN) for these
circuits to start operating properly. This additional time is specified with the
parameter start-up delay tSTRT. Figure 5-1 shows the timing diagram indicating this additional delay. After VDD is stable
and above VDD(MIN) subsequent changes of the sense voltage across the
threshold voltage will trigger reset after only the reset delay. The reset time
delay tD is set by a capacitor on the CTR pin. The start-up delay has a
max spec limit of 300μs for a ramp rate of
VDD ≤ 1V/μS.