DS1811R-15+T&R Analog Devices

DS1811 5V EconoReset with Open Drain Output www.maxim-ic.com FEATURES PIN ASSIGNMENT Automatically restarts a microprocessor after 3 power failure DALLAS DS1811 Maintains reset for 150 ms after V returns CC Econo Reset to an in-tolerance condition Reduces need for discrete components Precision temperature-compensated voltage 12 reference and voltage sensor TOP VIEW SOT-23 PACKAGE Low-cost TO-92 or space saving SOT-23 See Mech. Drawings Section packages available On Website 1 2 3 Efficient open-drain output with internal 5.5 k pull-up resistor 1 2 3 Operating temperature -40C to +85C BOTTOM VIEW TO-92 PACKAGE See Mech. Drawings Section On Website PIN DESCRIPTION TO-92 1 RST Active Low Reset Output 2 V Power Supply CC 3 GND Ground SOT-23 1 RST Active Low Reset Output 2 V Power Supply CC 3 GND Ground DESCRIPTION The DS1811 EconoReset uses a precision temperature reference and comparator circuit to monitor the status of the power supply (V ). When an out-of-tolerance condition is detected, an internal power-fail CC signal is generated which forces reset to the active state. When V returns to an in-tolerance condition, CC the reset signal is kept in the active state for approximately 150 ms to allow the power supply and processor to stabilize. 1 of 5 041002DS1811 OPERATION - POWER MONITOR The DS1811 provides the functions of detecting out-of-tolerance power supply conditions and warning a processor-based system of impending power failure. When V is detected as out-of-tolerance, the RST CC signal is asserted. On power-up, RST is kept active for approximately 150 ms after the power supply has reached the selected tolerance. This allows the power supply and microprocessor to stabilize before RST is released. BLOCK DIAGRAM (OPEN-DRAIN OUTPUT) Figure 1 APPLICATION EXAMPLE Figure 2 2 of 5