DALLAS DS1816-15

DS1816
3.3V EconoReset with
Open Drain Output
www.dalsemi.com
FEATURES
PIN ASSIGNMENT
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
20% tolerance for use with 3.0-volt systems
Low-cost TO-92 or space saving SOT-23
packages available
Efficient open-drain output with internal
5 kΩ=pull-up resistor
Operating temperature -40°C to +85°C
3
1
2
SOT-23 PACKAGE
1 2 3
1 2 3
TO-92 PACKAGE
See Mech.
Drawings Section
PIN DESCRIPTION
TO-92
1
2
3
RST
VCC
GND
Active Low Reset Output
Power Supply
Ground
SOT-23
1
2
3
RST
VCC
GND
Active Low Reset Output
Power Supply
Ground
DESCRIPTION
The DS1816 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 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.
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DS1816
OPERATION - POWER MONITOR
The DS1816 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 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
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DS1816
TIMING DIAGRAM: POWER-UP Figure 3
TIMING DIAGRAM: POWER-DOWN Figure 4
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DS1816
ABSOLUTE MAXIMUM RATINGS*
Voltage on VCC Pin Relative to Ground
Voltage on RST Relative to Ground
Operating Temperature
Storage Temperature
Soldering Temperature
*
-0.5V to +7.0V
-0.5V to VCC +0.5V
-40°C to +85°C
-55°C to +125°C
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
PARAMETER
Supply Voltage
SYMBOL
VCC
DC ELECTRICAL CHARACTERISTICS
PARAMETER
MIN
0.0
(-40°C to +85°C)
TYP
MAX
5.5
UNITS
V
NOTES
1
(-40°C to +85°C; VCC=1.2V to 5.5V)
SYMBOL
MIN
Output Current @ 0.4 V
IOL
+10
Operating Current VCC < 5.5V
ICC
TYP
MAX
UNITS
NOTES
mA
2, 3
28
35
µA
4
VCC Trip Point (DS1816-5)
VCCTP
2.98
3.06
3.15
V
1
VCC Trip Point (DS1816-10)
VCCTP
2.80
2.88
2.97
V
1
VCC Trip Point (DS1816-15)
VCCTP
2.47
2.55
2.64
V
1
RP
3.5
5.5
7.5
kΩ
7
10
pF
Internal Pull-Up Resistor
Output Capacitance
COUT
AC ELECTRICAL CHARACTERISTICS
PARAMETER
(-40°C to +85°C; VCC=1.2V to 5.5V)
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
VCC Slew Rate
(VCCTP (MIN) to VCCTP (MAX))
tR
0
ns
tRPU
100
VCC Detect to RST
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150
250
ms
8
5, 6
DS1816
NOTES:
1. All voltages are referenced to ground.
2. Measured with VCC ≥ 2.7V.
3. A 1kΩ=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.
A . . . . . . 5%
B . . . . . . 10%
C . . . . . . 15%
D . . . . . . 20%
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