Texas Instruments Inc. is offering two tiny push-button reset controllers for space-constrained, power-sensitive applications such as pedometers, fitness bands, cell phones and tablets. The dual-channel TPS3420 and TPS3421 feature low power consumption and a selectable reset time delay to improve system stability.
Push-button reset controllers are required for portable electronics with an embedded battery. In practice, the user presses and holds one or two external keys for a specific period of time, which turns the portable device off or generates a reset. The TPS3420 and TPS3421 use a long input delay to provide the intended system reset and avoid reset from short push-button or key presses. This reset configuration enables differentiation between software interrupts and hard system resets. The timers are the first in a family of new push-button controllers from TI to ensure a hard and full system reset when needed to increase efficiency.
- Selectable input delay of 7.5 or 12.5 seconds eliminates unintended resets.
- Low 250-nA quiescent current conserves power for portable electronics.
- Selectable reset pulse of 400 or 800 milliseconds allows for flexible initializing.
- Small 1.45-mm by 1.0-mm by 0.55-mm SON package consumes 70 percent less board space than competitive devices.
Availability, packaging and pricing
The TPS3420 and TPS3421 push-button reset controllers are available in volume now from TI and its authorized distributors. Offered in a 6-pin SON package, the controllers are priced at US$0.40 in 1,000-unit quantities. For those applications requiring a single push-button input, TI offers the TPS3422 priced at US$0.34.
TPS3420 and TPS3421