FEATURES
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LTC2935 Ultra-Low Power Supervisor with Power-Fail Output, Selectable Thresholds DESCRIPTION
The LTC®2935 ultra-low power voltage monitor provides system initialization, power-fail warning and reset generation functions. Low quiescent current (500nA typical) makes the LTC2935 an ideal choice for battery-operated applications. Three binary threshold-select inputs configure one of eight integrated reset thresholds, available from 3. 3V to 2. 25V in 150mV increments. Early warning of an impending low voltage condition is provided at the power-fail output (PFO), whose threshold is 150mV above the configured reset threshold. Supervisory circuits monitor VCC and pull RST low when VCC drops below the configured reset threshold. When VCC is rising from an under-threshold condition, an internal reset timer is started after exceeding the reset threshold by 5%. A 200ms reset timeout delays the return of the RST output to a high state. A pushbutton switch connected to the MR input is typically used to force a manual reset. Outputs RST and PFO are available with open-drain (LTC2935-1) or active pull-up (LTC2935-2) circuits. Operating temperature range is from –40ºC to 85ºC.
500nA Quiescent Current ±1. 5% (Max) Accuracy over Temperature Integrated Precision Attenuators Eight Pin-Selectable Reset Thresholds Eight Pin-Selectable Power-Fail Thresholds Early Warning Power-Fail Output 200ms Reset Timeout Manual Reset Input Compact 8-Lead, 2mm × 2mm DFN and TSOT-23 (ThinSOT™) Packages
APPLICATIONS
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Portable Equipment Battery-Powered Equipment Security Systems Point-of-Sale Devices Wireless Systems
, LT, LTC, LTM are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
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TYPICAL APPLICATION
Configurable Low Power Voltage Monitor
VIN VCC 0. 1μF S2 S1 S0 MR GND
2935 TA01a
Falling Threshold Selection Table
RESET ...
LTC2935 PDF File
