DS1233D Datasheet, PDF (1/5 Pages) Dallas Semiconductor – 5V EconoReset

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DS1233D
5V EconoReset
FEATURES
§ Automatically restarts microprocessor after
power failure
§ Maintains reset for 350 ms after V_CC returns
to an in-tolerance condition
§ 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
SOT-223 package
§ Internal 5 kW pull-up resistor
§ Compatible with Motorola 68XXX series and
HC16 Microprocessors
§ Operating temperature of -40°C to +85°C
PIN ASSIGNMENT
DALLAS
1
DS1233
Econo
Reset
123
123
BOTTOM VIEW
TO-92 PACKAGE
See Mech.
Drawings Section
On Website
24 3
TOP VIEW
SOT-23 PACKAGE
See Mech.
Drawings Section
On Website
PIN DESCRIPTION
PIN 1
GROUND
PIN 2
RESET
PIN 3
PIN 4
V_CC
GROUND (SOT-223 ONLY)
DESCRIPTION
The DS1233D EconoReset uses a precision temperature-compensated reference and comparator circuit to
monitor the status of the power supply (V_CC). When an out-of-tolerance condition is detected, an internal
power-fail signal is generated which forces reset to the active state. When V_CC returns to an in-tolerance
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 DS1233D provides the functions of detecting out-of-tolerance power supply conditions and warning
a processor-based system of impending power failure. When V_CC 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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