Supervisory Circuits with Windowed Watchdog and Manual Reset in 5-Lead SOT-23 Data Sheet ADM8323/ADM8324 FEATURES FUNCTIONAL BLOCK DIAGRAMS Windowed watchdog, 8 timeout options ADM8323 26 reset threshold options V CC 2.5 V to 5 V in 100 mV increments V CC RESET 4 reset timeout options RESET GENERATOR V REF 1 ms, 20 ms, 140 ms, and 1120 ms (minimum) Manual reset input MR DEBOUNCE RESET Open-drain or push-pull outputs WINDOWED WATCHDOG Low power consumption DETECTOR Specified over wide temperature range (40C to +125C) Qualified for automotive applications GND WDI 5-lead SOT-23 package Figure 1. APPLICATIONS ADM8324 Automotive Microprocessor systems V RESET Computers CC RESET GENERATOR Controllers V REF Intelligent instruments Portable equipment MR DEBOUNCE WINDOWED WATCHDOG DETECTOR GND WDI Figure 2. GENERAL DESCRIPTION The ADM8323/ADM8324 are supervisory circuits that monitor Each device is available in a choice of 26 reset threshold options power supply voltage levels and code execution integrity in from 2.5 V to 5 V in 100 mV increments. There are also four reset microprocessor-based systems. An on-chip watchdog timer checks timeout options of 1 ms, 20 ms, 140 ms, and 1120 ms (minimum). for activity within a preset timeout window. A reset signal can also Not all device options are available as standard models. See the Ordering Guide for details. be asserted by an external push-button switch through a manual reset input. The RESET output is either push-pull (ADM8323) The ADM8323/ADM8324 are available in a 5-lead SOT-23 or open-drain (ADM8324). package and typically consume only 10 A, making them suitable for use in low power portable applications. A watchdog failure results in a low output on the pin. A RESET failure can be triggered either by a fast watchdog error (watchdog pulses too close together) or by a slow watchdog error (no watchdog pulse within the timeout period). This effectively gives a window to observe the watchdog pulse. The watchdog timeout is measured from the last falling edge of the watchdog input (WDI). There are eight different watchdog windows available, as shown in Table 5. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20132018 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. 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Technical Support www.analog.com 11802-001 11802-002ADM8323/ADM8324 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Push-Pull RESET Output .......................................................... 10 Applications ....................................................................................... 1 Open-Drain RESET Output ..................................................... 10 Functional Block Diagrams ............................................................. 1 Manual Reset Input .................................................................... 10 General Description ......................................................................... 1 Windowed Watchdog Input ...................................................... 10 Revision History ............................................................................... 2 Applications Information .............................................................. 11 Specifications ..................................................................................... 3 Watchdog Input Current ........................................................... 11 Absolute Maximum Ratings ............................................................ 5 Negative Going V Transients ................................................. 11 CC ESD Caution .................................................................................. 5 Ensuring RESET Valid to V = 0 V ........................................ 11 CC Pin Configuration and Function Descriptions ............................. 6 Model Options ................................................................................ 12 Typical Performance Characteristics ............................................. 7 Outline Dimensions ....................................................................... 13 Theory of Operation ...................................................................... 10 Ordering Guide .......................................................................... 13 Circuit Description..................................................................... 10 Automotive Products ................................................................. 14 REVISION HISTORY 2/2018Rev. A to Rev. B Changes to General Description Section ...................................... 1 Added Note 3, Table 1 ...................................................................... 3 Changed Model Options Section to Device Model Options Section .............................................................................................. 12 Changes to Device Model Options Section ................................ 12 Deleted Table 7 Renumbered Sequentially................................. 13 Changes to Ordering Guide .......................................................... 13 3/2016Rev. 0 to Rev. A Change to Model Options Section Title ...................................... 12 Changes to Table 7 .......................................................................... 13 10/2013Revision 0: Initial Version Rev. B Page 2 of 15