Microprocessor Supervisory Circuit ADM809-5L/ADM809-5S FEATURES FUNCTIONAL BLOCK DIAGRAM Specified over temperature ADM809-5L/ ADM809-5S Low power consumption: 17 A Precision voltage monitor: 3 V, 5 V options V CC RESET GENERATOR Reset assertion down to 1 V V CC RESET 55ms V REF 30 ms minimum power-on reset Logic low RESET output Available in SOT-23 and SC70 packages GND Figure 1. APPLICATIONS Microprocessor systems Computers Controllers Intelligent instruments Automotive systems GENERAL DESCRIPTION TYPICAL OPERATING CIRCUIT V CC The supervisory circuit of the ADM809-5L/ADM809-5S monitors the power supply voltage in microprocessor systems. It provides V V CC CC a reset output during power-up, power-down, and brownout MICROPROCESSOR ADM809-5L/ SYSTEM conditions. On power-up, an internal timer holds reset asserted ADM809-5S RESET INPUT RESET for 55 ms. This holds the microprocessor in a reset state until RESET conditions have stabilized. The output remains operational GND GND with V as low as 1 V. The ADM809-5L/ADM809-5S provide CC an active low reset signal (RESET). Figure 2. The reset comparator features built-in glitch immunity, making it immune to fast transients on VCC. The ADM809-5L/ADM809-5S consume only 17 A, making them suitable for low power, portable equipment. Rev. B 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 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 00090-001 00090-002ADM809-5L/ADM809-5S TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Function Descriptions ..............................5 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................6 General Description ......................................................................... 1 Theory of Operation .........................................................................7 Functional Block Diagram .............................................................. 1 Interfacing to Output of Other Devices .....................................7 Typical Operating Circuit ................................................................ 1 Ensuring a Valid Reset Output Down to VCC = 0 V .................7 Revision History ............................................................................... 2 RESET Benefits of a Very Accurate Threshold .............................7 Specif icat ions ..................................................................................... 3 Interfacing to Microprocessors with Multiple Interrupts ........7 Absolute Maximum Ratings ............................................................ 4 Outline Dimensions ..........................................................................8 ESD Caution .................................................................................. 4 Ordering Guide .............................................................................8 REVISION HISTORY 10/08Rev. A to Rev. B Updated Format .................................................................. Universal Updated Outline Dimensions ......................................................... 8 Changes to Ordering Guide ............................................................ 8 3/03Rev. 0 to Rev. A Added SC70 Package .......................................................... Universal Changes to Features ......................................................................... 1 Changes to Specifications ............................................................... 2 Changes to Absolute Maximum Ratings ...................................... 2 Changes to Table I .......................................................................... 3 Changes to Ordering Guide ........................................................... 3 Changes to TPC 2 ............................................................................ 4 Updated Outline Dimensions ........................................................ 6 Rev. B Page 2 of 8