Dallas Semiconductor DS1815R-10-T-R, DS1815-5, DS1815-20, DS1815-10, DS1815R-5-T-R Datasheet

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FEATURES

 Automatically restarts a microprocessor after

power failure

 Maintains reset for 150 ms after VCC returns

to an in-tolerance condition

 Reduces need for discrete components
 Precision temperature-compensated voltage

reference and voltage sensor

 Accurate 5%, 10% or 20% power monitoring
 Low-cost TO-92 or space saving surface-

mount SOT-23 packages available

 Push-pull output for low current operation
 Operating temperature -40°C to +85°C

PIN ASSIGNMENT

PIN DESCRIPTION
TO-92

1 RST Active Low Reset Output
2 VCC Power Supply
3 GND Ground

SOT-23

1 RST Active Low Reset Output
2 V

CC

Power Supply

3 GND Ground

DESCRIPTION

The DS1815 EconoReset uses a precision temperature reference and comparator circuit to monitor the
status of the power supply (VCC). When an out-of-tolerance condition is detected, an intern al power-fail
signal is generated which forces reset to t he active state. When V

CC

returns to an in-tolerance condition,
the reset signal is kept in the active state for approximately 150 ms to allow the power supply and
processor to stabilize.

DS1815

3.3V EconoReset with Push-Pull Output

www.dalsemi.com

12

3

SOT-23 PACKAGE

1 2 3

1 2 3

TO-92 PACKAGE

See Mech.

Drawings Section

DS1815

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OPERATION - POWER MONITOR

The DS1815 provides the functions of detecting out-of-tolerance power supply conditions and warning a
processor-based system of impending power failure. When VCC is detected as out of tolerance, the RST
signal is asserted. On power-up, RST is kept active for approximately 150 ms after the pow er suppl y has
reached the selected tolerance. This allows the power supply and microprocessor to stabilize befor e RST

is released.

BLOCK DIAGRAM (CMOS OUTPUT) Figure 1

APPLICATION EXAMPLE Figure 2

APP LICATION DIAGRAM:

RST VALID TO 0 VOLTS V

CC

ON THE DS1815 Figure 3