ADM6823TYRJZ-RL7

The ADM682x are supervisory circuits that 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. Each part is available in nine reset threshold options, ranging from 1.58 V to 4.63 V. The reset and watchdog timeout periods are fixed at 140 ms (min) and 1.6 sec (typ), respectively. The ADM682x are available in 5-lead SOT-23 packages and typically consume only 7 μA, making them suitable for use in low power, portable applications. The ADM682x provide microprocessor supply voltage supervision by controlling the microprocessor’s reset input. Code execution errors are avoided during power-up, powerdown, and brownout conditions by asserting a reset signal when the supply voltage is below a preset threshold. In addition, the ADM682x allow supply voltage stabilization with a fixed timeout before the reset deasserts after the supply voltage rises above the threshold. Problems with microprocessor code execution can be monitored and corrected with a watchdog timer (ADM6821/ ADM6822/ADM6823/ADM6824). When watchdog strobe instructions are included in microprocessor code, a watchdog timer detects if the microprocessor code breaks down or becomes stuck in an infinite loop. If this happens, the watchdog timer asserts a reset pulse, which restarts the microprocessor in a known state. If the user detects a problem with the system’s operation, a manual reset input is available (ADM6821/ADM6822/ ADM6823/ADM6825) to reset the microprocessor by means of an external push-button, for example.

Applications

• Microprocessor systems
• Computers
• Controllers
• Intelligent instruments
• Portable equipment

Key features

• Precision low voltage monitoring
• 9 reset threshold options: 1.58 V to 4.63 V
• 140 ms (min) reset timeout
• Watchdog timer with 1.6 sec timeout
• Manual reset input
• Reset output stages Push-pull active-low Open-drain active-low Push-pull active-high
• Low power consumption (7 μA)
• Guaranteed reset output valid to Vcc = 1 V
• Power supply glitch immunity
• Specified from -40°C to +125°C
• 5-lead SOT-23 package