Ultra-Low Power Adjustable Supervisor with Power-Fail Output

The LTC2934 ultra-low power voltage monitor provides system initialization, power-fail warning and reset generation functions. Low quiescent current (500nA typical) makes the LTC2934 an ideal choice for battery-operated applications.

Precision power-fail and reset voltages can be configured independently. Early warning of an impending low voltage condition is provided at the power-fail output (PFO) when the PFI input falls below 0.4V. Supervisory circuits monitor the ADJ input and pull RST low when ADJ falls below 0.4V. When ADJ is rising from an under-threshold condition, an internal reset timer is started after exceeding the ADJ threshold by 5%. The 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 (LTC2934-1) or active pull-up circuits (LTC2934-2). Operating temperature range is from –40ºC to 85ºC.

Applications

* Portable Equipment

* Battery-Powered Equipment

* Security Systems

* Point-of-Sale Devices

* Wireless Systems

* 500nA Quiescent Current

* ±1.5% (Max) Accuracy over Temperature

* Operates Down to 1.6V Supply

* Adjustable Reset Threshold

* Adjustable Power-Fail Threshold

* Early Warning Power-Fail Output

* Selectable 15ms or 200ms Reset Timeout

* Manual Reset Input

* Compact 8-Lead, 2mm × 2mm DFN and TSOT-23 (ThinSOT™) Packages