Preliminary Technical Data
FEATURES
Supervisory Circuits with Watchdog and Manual Reset in 5-Lead SC70 and SOT-23 ADM82...
Preliminary Technical Data
FEATURES
Supervisory Circuits with Watchdog and Manual Reset in 5-Lead SC70 and SOT-23 ADM823/ADM824/ADM825
FUNCTIONAL BLOCK DIAGRAM
ADM823
VCC VREF VCC RESET GENERATOR
Precision 2.5 V to 5 V power supply monitor 7 reset threshold options: 2.19 V to 4.63 V 140 ms (min) reset timeout Watchdog timer with 1.6s timeout (ADM823, ADM824) Manual reset input (ADM823, ADM825) Push-pull output stages: RESET (ADM823) RESET, RESET (ADM824/ADM825) Low power consumption (3 µA) Guaranteed reset output valid to VCC = 1 V Power supply glitch immunity Specified over automotive temperature range 5-lead SC70 and SOT-23 packages
RESET
MR
DEBOUNCE WATCHDOG DETECTOR
04534-0-001
GND
WDI
Figure 1.
APPLICATIONS
Microprocessor systems Computers Controllers Intelligent instruments Portable equipment
GENERAL DESCRIPTION The ADM823/ADM824/ADM825 are supervisory circuits which monitor power supply
voltage levels and code execution integrity in microprocessor-based systems. As well as providing power on reset signals, an on-chip watchdog timer can reset the microprocessor if it fails to strobe within a preset timeout period. A reset signal can also be asserted by means of an external push-button, through a manual reset input. The three parts feature different combinations of watchdog input, manual reset input and output stage configuration, as shown in Table 1. Each part is available in a choice of seven reset threshold options ranging from 2.19 V to 4.63 V. The reset an...