The TPS3420, TPS3421, and TPS3422 (TPS342x) are low-current, ultrasmall, push-button reset timers. These devices use a long timing setup delay to provide the intended system reset, and avoid resets from short push-button closures or key presses. This reset configuration also allows for differentiation between software interrupts and hard system resets.
●The TPS3420 and TPS3421 monitor two inputs (PB1 and PB2) and output an active-low reset pulse signal (RST) when both inputs are low for the selected time delay. For the TPS3421, RST remains low for a factory-programmed fixed time. For the TPS3420, RST remains low until one of the PBx inputs is released. The need for a dedicated reset button is eliminated because two inputs are used to ensure reset. The TPS3422 monitors one input (PB1) and outputs an active-low reset pulse signal (RST) when PB1 is low for the selected time delay.
●The TPS342x have an open-drain output that can be wire-ORed with other open-drain devices. The TPS342x operate from 1.6 V to 6.5 V over the 40°C to +125°C temperature range, and provide a precise, space-conscious micropower solution for system resetting needs.
● Very Small Package: 1.45-mm × 1.00-mm SON
● Operating Range: 1.6 V to 6.5 V
● Single (TPS3422) or Dual (TPS3420 and
●TPS3421) Push-Button Inputs
● Low Supply Current: 250 nA (Typical)
● Two-State Logic, User-Selectable Input Delay:
● For Example: 7.5 s and 0 s
● Multiple Timing Options Available
● Fixed Time-out Pulse at RST (TPS3421 and
●TPS3422): 400 ms (Typical)
● Other Timing Options Available on Request
● Active Low, Open-Drain Output
