LTC2956 Wake-Up Timer with Pushbutton Control FEATURESDESCRIPTION n 1.5V to 36V Supply Input Range The LTC®2956 is a micropower, wide input voltage range, n Adjustable Wake-Up Period: 250ms to 39 Days configurable wake-up timer with pushbutton control. It n Adjustable Maximum Awake Time periodically wakes up and turns on a connected system n 0.8µA Quiescent Current to perform tasks like monitoring temperature or capturing n 0.3µA Shutdown Current images. After completing the task, the LTC2956 turns the n Pushbutton Input with Debouncing system off to conserve power. n Low Leakage EN Output Allows DC/DC Converter The wake-up timer period can be adjusted from 250ms to Control (LTC2956-1) 39 days using configuration resistors. The system awake n High Voltage EN Output Drives External P-Channel time can be controlled by the input pulse at the SLEEP MOSFET (LTC2956-2) pin or adjusted by the capacitor at the ONMAX pin. The n ±25kV ESD HBM on PB Input LTC2956 operates over a wide supply input range from n 12-Lead 3mm × 3mm QFN and MSOP Packages 1.5V to 36V. The low 800nA quiescent current suits bat- tery powered applications. APPLICATIONS The pushbutton input allows the user to shutdown, turn n Heartbeat Timers on or reset the wake-up timer. With the timer in shutdown, n Periodic Wake-Up Control the quiescent current drops to 300nA. The LTC2956 also n Portable and Battery-Powered Equipment provides three status outputs to indicate mode transitions n Intervalometers and pushbutton events. Two versions are available for n Data Acquisition applications requiring either positive or negative enable polarities. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION V LT3060 BAT V + IN VOUT VMAIN SHORT PRESS STARTS LONG PRESS STOPS 1µF SHDN CYCLING TIMER CYCLING TIMER 10k 10k PB VIN EN 10k ONMAX LTC2956-1 PBOUT µP SHUTS OFF TURNED ON 1.5nF SLEEP POWER ONALERT TURNING OFF OFFALERT PB µP TIMER PERIODICALLY SLEEP GND ENABLES POWER LONG RANGE PERIOD EN 100k 100k 280k 9.76k tAWAKE tSLEEP 2956 TA01b tPERIOD tLONG = 1s, tONMAX = 20ms, tPERIOD = 250ms 2956 TA01a 2956fa For more information www.linear.com/LTC2956 1
