DS1818 ,3.3V EconoReset with PushbuttonFEATURES PIN ASSIGNMENT • Improves Reliability of Processor Operation 3 o Temperature-Compensat ..
DS1818 ,3.3V EconoReset with PushbuttonPIN DESCRIPTION o Fixed 3.3V Reset Threshold TO-92 o 5%, 10%, and 20% Tolerance Versions 1 RS ..
DS1818-10 ,3.3V EconoReset with PushbuttonPIN DESCRIPTIONTO-921 RST Active Low Reset Output2 V Power SupplyCC3 GND GroundSOT-231 RST Active L ..
DS1818-10 ,3.3V EconoReset with PushbuttonFEATURES PIN ASSIGNMENT Automatically restarts a microprocessor after3power failure Monitors push ..
DS1818-5+ ,3.3V EconoReset with PushbuttonFEATURES PIN ASSIGNMENT • Improves Reliability of Processor Operation 3 o Temperature-Compensat ..
DS1818R-10/T&R ,3.3V EconoReset with PushbuttonPIN DESCRIPTION o Fixed 3.3V Reset Threshold TO-92 o 5%, 10%, and 20% Tolerance Versions 1 RS ..
DXT3150-13 , NPN SURFACE MOUNT TRANSISTOR
DXT3904 , TECHNICAL SPECIFICATIONS OF NPN EPITAXIAL PLANAR TRANSISTOR
DXT3904-13 , NPN SURFACE MOUNT TRANSISTOR
DXT5551 , TECHNICAL SPECIFICATIONS OF NPN EPITAXIAL PLANAR TRANSISTOR
DXT651-13 , LOW VCE(SAT) NPN SURFACE MOUNT TRANSISTOR
DZ23C10 ,Zener DiodesDZ23C2V7–DZ23C51Vishay Telefunken300 mW Dual Surface Mount Zener Diodes
DS1818
3.3V EconoReset with Pushbutton
BENEFITS AND FEATURES • Improves Reliability of Processor Operation Temperature-Compensated Voltage
Monitor for Precise, Automated Power-
Fail Detection Automatically Restarts a Microprocessor
After Power Failure Maintains Reset for 150ms After VCC
Returns to Tolerance for Processor
Stabilization Monitors Pushbutton for External
Override Active-Low Reset Output • Efficient Open-Drain Output with Internal 5.5kΩ Pullup Resistor Saves Power and Space 35μA (max) Quiescent Current • Allows for Easy Design with No Complicated
Settings Fixed 3.3V Reset Threshold 5%, 10%, and 20% Tolerance Versions
Available • Operates in Most Commercial and Industrial
Environments -40°C to +85°C Operating Temperature
Range • MXD1818 Offers Improved Performance over
the DS1818
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 VCC Power Supply
3 GND Ground
DESCRIPTION The DS1818 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 state. When VCC 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.
The DS1818 also monitors a pushbutton on the reset output. If the reset line is pulled low, a reset is
generated upon release and the DS1818 output will be held in reset output low for typically 150 ms.
DS1818
3.3V EconoReset with Pushbutton 2
TOP VIEW
SOT-23 PACKAGE
See Mech.
Drawings Section
On Website1 2 3
1 2 3
BOTTOM VIEW
TO-92 PACKAGE
See Mech.
Drawings Section
On Website
DALLAS
DS1818
Econo
Reset
DS1818
OPERATION - POWER MONITOR The DS1818 provides the functions of detecting out-of-tolerance power supply conditions and warning a
processor-based system of impending power failures. 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 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
OPERATION - PUSHBUTTON RESET The DS1818 provides a pushbutton switch for manual reset control. When the DS1818 is not in a reset
cycle, a pushbutton reset can be generated by pulling the RST pin low for at least 1 µs. When the
pushbutton is held low, the RST is forced active low and will remain active low for about 150 ms after
the pushbutton is released. See Figure 2 for an application example and Figure 3 for the timing diagram.
TIMING DIAGRAM: PUSHBUTTON RESET Figure 3 DS1818
TIMING DIAGRAM: POWER-UP Figure 4
TIMING DIAGRAM: POWER-DOWN Figure 5 DS1818
ABSOLUTE MAXIMUM RATINGS* Voltage on VCC Pin Relative to Ground -0.5V to +7.0V
Voltage on RST Relative to Ground -0.5V to +5VCC +0.5V
Operating Temperature -40°C to +85°C
Storage Temperature -55°C to +125°C
Soldering Temperature 260°C for 10 seconds
This is a stress rating only and functional operation of the device at these or any other conditions
above 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)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Supply Voltage VCC 1.0 5.5 V 1
DC ELECTRICAL CHARACTERISTICS (-40°C to +85°C; VCC=1.2V to 5.5V)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Output Current @ 0.4 V IOL +10 mA 2, 3
Voltage Input Low VIL 0.4 V 1
Voltage Input High VIH 0.7
*VCC V 1
Operating Current VCC < 5.5V ICC 28 35 µA 4
VCC Trip Point (DS1818-5) VCCTP 2.98 3.06 3.15 V 1
VCC Trip Point (DS1818-10) VCCTP 2.80 2.88 2.97 V 1
VCC Trip Point (DS1818-20) VCCTP 2.47 2.55 2.64 V 1
Internal Pull-up Resistor RP 3.50 5.5 7.5 kΩ 7
Output Capacitance COUT 10 pF
AC ELECTRICAL CHARACTERISTICS (-40°C to +85°C; VCC=1.2V to 5.5V)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES RESET Active Time tRST 100 150 250 ms 5
VCC Detect to RST tRPD 2 5 µs
VCC Slew Rate
(VCCTP (MAX) to VCCTP (MIN))
tF 300 µs 8
VCC Slew Rate
(VCCTP (MIN) to VCCTP (MAX))
tR 0 ns
VCC Detect to RST tRPU 100 150 250 ms 5, 6
Pushbutton Detect to RST tPB 1 µs
DS1818
NOTES: 1. All voltages are referenced to ground.
2. Measured with VCC ≥ 2.7V.
3. A 1 kΩ external pull-up resistor may be required in some applications for proper operation of the
microprocessor reset control circuit.
4. Measured with RST output open.
5. Measured with 2.7V ≤ VCC ≤ 3.3V.
6. tR = 5 µs.
7. VOH and IOH are a function of the value of RP and the associated output load conditions.
8. The tF value is for reference in defining values for tRPD and should not be considered a requirement for
proper operation or use of the device.
PART MARKING CODES “A”, “B”, &“C” represent the device type.
810 - DS1810
811 - DS1811
812 - DS1812
813 - DS1813
815 - DS1815
816 - DS1816
817 - DS1817
818 - DS1818
“D” represents the device tolerance. - 5% - 10% - 15% - 20%
DS1818
REVISION HISTORY
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED 3/15 Updated Benefits and Features section 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
