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DS1833
5V EconoReset
FEATURES
PIN ASSIGNMENT
§ Automatically restarts microprocessor after
power failure
§ Maintains active-high reset for 350 ms after
VCC returns to an in-tolerance condition
DALLAS
DS1833
Econo
Reset
1
§ Accurate 5%, 10% or 15% microprocessor 5V
power supply monitoring
§ Reduces need for discrete components
§ Precision temperature-compensated voltage
reference and voltage sensor
§ Low-cost TO-92 package or surface mount
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4
2
TOP VIEW
SOT-23 PACKAGE
See Mech.
Drawings Section
On Website
SOT-223 package
§ Internal 5k pull-up resistor
§ Operating temperature of -40°C to +85°C
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BOTTOM VIEW
TO-92 PACKAGE
See Mech.
Drawings Section
On Website
PIN DESCRIPTION
PIN 1 Ground
PIN 2 Reset
PIN 3 V
CC
PIN 4 Ground (SOT-223 only)
DESCRIPTION
The DS1833 EconoReset uses a precision temperature compensated reference and comparator circuit to
monitor the status of the power supply (VCC). When an out-of-tolerance condition is detected, an internal
power fail signal is generated which forces reset to the active (high) state. When VCC returns to an intolerance condition, the reset signal is kept in the active state for approximately 350 ms to allow the
power supply and processor to stabilize.
OPERATION - POWER MONITOR
The DS1833 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, as
defined by the tolerance of the part selected, the RST signal is asserted. On power-up, RST is kept active
for approximately 350 ms after the power supply has reached the selected tolerance. This allows the
power supply and microprocessor to stabilize before RST is released.
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BLOCK DIAGRAM Figure 1
DS1833
APPLICATION EXAMPLE Figure 2
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