DS1233-15 ,5V EconoResetFEATURES PIN ASSIGNMENT Automatically restarts microprocessor afterpower failureDALLASDS1233A Mon ..
DS1233-15+ ,5V EconoResetDS12335V EconoReset
DS1233-15+ ,5V EconoResetDS12335V EconoReset
DS1233-5 ,5V EconoResetPIN DESCRIPTIONPIN 1 GROUNDPIN 2 RESETPIN 3 VCCPIN 4 GROUND (SOT-223 ONLY)DESCRIPTIONThe DS1233D Ec ..
DS1233-5+ ,5V EconoResetapplications where additional reset current is required, aminimum capacitance of 500pF should be us ..
DS1233-5+ ,5V EconoResetDS12335V EconoReset
DTA143XK , DTA/DTC SERIES
DTA143XM , Digital transistors (built-in resistors)
DTA143XS , DTA/DTC SERIES
DTA143XS , DTA/DTC SERIES
DTA143XSA , PNP Digital Transistors (Built-in Resistors)
DTA143XUA , PNP Digital Transistors (Built-in Resistors)
DS1233-15-DS1233A-15-DS1233D-10
5V EconoReset
FEATURESAutomatically restarts microprocessor after
power failureMonitors pushbutton for external overrideInternal circuitry debounces pushbutton
switchMaintains reset for 350ms after VCC returns to
an in-tolerance condition or pushbutton
releasedAccurate 10% or 15% microprocessor 3.3V
power supply monitoringReduces need for discrete componentsPrecision temperature-compensated voltage
reference and voltage sensorLow-cost TO-92 package or surface mount
SOT-223 packageInternal 5k��pull-up resistorOperating temperature of -40�C to +85�C
PIN ASSIGNMENT
PIN DESCRIPTIONPIN 1GROUND
PIN 2RESETPIN 3VCC
PIN 4GROUND (SOT-223 ONLY)
DESCRIPTIONThe DS1233A EconoReset monitors two vital conditions for a microprocessor: power supply and external
override. A precision temperature-compensated reference and comparator circuit are used 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 state. When VCC returns to an in-tolerance condition,the reset signal is kept in the active state for approximately 350ms to allow the power supply and
processor to stabilize. The second function of the DS1233A is pushbutton reset control. The DS1233A
debounces a pushbutton closure and will generate a 350ms reset pulse upon release.
OPERATION — POWER MONITORThe DS1233A provides the functions of detecting out-of-tolerance power supply conditions and warninga 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 350ms after the power supply has reached the selected tolerance. This allows the power
supply and microprocessor to stabilize before RST is released.
3.3V EconoReset1 2 3
1 2 3
BOTTOM VIEW
TO-92 PACKAGE
See Mech.
Drawings Section
on Website4
TOP VIEW
SOT-223 PACKAGE
See Mech.
Drawings Section
on Website
DS1233A
OPERATION — PUSHBUTTON RESETThe DS1233A provides for a pushbutton switch to be connected to the RST output pin. When the
DS1233A is not in a reset cycle, it continuously monitors the RST signal for a low-going edge. If an edge
is detected, the DS1233A will debounce the switch by pulling the RST line low. After the internal timer
has expired, the DS1233A will continue to monitor the RST line. If the line is still low, the DS1233A willcontinue to monitor the line looking for a rising edge. Upon detecting a release, the DS1233A will force
the RST line low and hold it low for 350ms.
NOTE:For proper operation with an external pushbutton, a capacitor between 100pF and 0.01�F must be
connected between RST and ground. In applications where additional reset current is required, a
minimum capacitance of 500 pF should be used, along with a parallel external pull-up resistor of 1k�
minimum.
BLOCK DIAGRAM Figure 1
APPLICATION EXAMPLE Figure 2
DS1233A
PUSHBUTTON RESET Figure 3
POWER-UP Figure 4
POWER-DOWN Figure 5
DS1233A
ABSOLUTE MAXIMUM RATINGS*Voltage on VCC Pin Relative to Ground -0.5V to +7.0V
Voltage on I/O Relative to Ground -0.5V to VCC +0.5V
Operating Temperature Range-40°C to +85°C
Storage Temperature Range-55°C to +125°C
Soldering Temperature 260°C for 10 secondsThis is a stress rating only and functional operation of the device at these or any other conditionsabove those indicated in the operation sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods of time may affect reliability.
RECOMMENDED DC OPERATING CONDITIONS (-40�C to +85�C)
DC ELECTRICAL CHARACTERISTICS (-40�C to +85�C; VDD = 3.3V � 10%)
AC ELECTRICAL CHARACTERISTICS (-40�C to +85�C; VCC = 3.3V � 10%)
NOTES:1) All voltages are referenced to ground.
2) With a 100pF to 0.01�F capacitor connected from RST to ground.
DS1233A
ECONORESET SELECTION GUIDE
This datasheet has been :
www.ic-phoenix.com
Datasheets for electronic components.
