NSC LM8364BALMF30 Micropower undervoltage sensing circuit Datasheet

LM8364
Micropower Undervoltage Sensing Circuits
General Description
Features
The LM8364 series are micropower undervoltage sensing
circuits that are ideal for use in battery powered microprocessor based systems, where extended battery life is a key
requirement.
A range of threshold voltages from 2.0V to 4.5V are available
with an active low open drain output. These devices feature
a very low quiescent current of 0.65µA typical. The LM8364
series features a highly accurate voltage reference, a comparator with precise thresholds and built-in hysterisis to prevent erratic reset operation, and guaranteed Reset operation
down to 1.0V with extremely low standby current.
n Extremely Low Quiescent Current: 0.65µA, at VIN =
2.87V
n High Accuracy Threshold Voltage ( ± 2.5%)
n Open Drain Output
n Input Voltage Range: 1V to 6V
n Surface Mount Package (5-Pin SOT23)
n Pin for pin compatible with MC33464
These devices are available in the space saving SOT23
5-pin surface mount package. For other undervoltage
thresholds and output options, please contact National
Semiconductor.
Functional Block Diagram
Applications
n
n
n
n
Low Battery Detection
Microprocessor reset Controller
Power Fail Indicator
Battery Backup Detection
Connection Diagram
5-Pin SOT23
20065906
Top View
20065907
© 2003 National Semiconductor Corporation
DS200659
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LM8364 Micropower Undervoltage Sensing Circuits
March 2003
LM8364
Pin Description
20065908
Ordering Information
Package
Part Number
LM8364BALMF20
LM8364BALMFX20
5-Pin
SOT23
LM8364BALMF30
LM8364BALMFX30
LM8364BALMF45
LM8364BALMFX45
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Package
Marking
Threshold
Output Type
Transport Media
F01A
2.0V
Open Drain,
Active Low
3k Units Tape and Reel
F05A
3.0V
Open Drain,
Active Low
3k Units Tape and Reel
F04A
4.5V
Open Drain,
Active Low
3k Units Tape and Reel
2
NSC Drawing
1k Units Tape and Reel
1k Units Tape and Reel
1k Units Tape and Reel
MF05A
Junction Temperature
(Note 1)
125˚
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Operating Ratings (Note 1)
Supply Voltage
−0.3V to 6.5V
Temperature Range
−0.3V to 6.5V
Thermal Resistance to ambient (θJA)
RESET Output Voltage
RESET Output Current
Storage Temperature Range
−40˚C to 85˚C
265˚C/W
ESD Tolerance
70mA
Human Body Model
−65˚C to 150˚C
2000V
Machine Model
Mounting Temp.
Lead temp (Soldering, 10 sec)
200V
260˚C
Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TA = 25˚C.
Symbol
VDET−
VHYS
Parameter
Detector Threshold Voltage
Detector Threshold
Hysteresis
Conditions
Min
(Note 3)
Typ
(Note 2)
Max
(Note 3)
Units
20 Suffix
1.950
2.0
2.050
V
30 Suffix
2.925
3.0
3.075
45 Suffix
4.388
4.5
4.613
20 Suffix
0.060
0.100
0.140
30 Suffix
0.090
0.150
0.210
45 Suffix
0.135
0.225
0.315
High to Low State Output
(VIN Decreasing)
VIN Increasing
∆Vdet/∆T
Detector Threshold Voltage
Temperature Coefficient
VOL
RESET Output Voltage Low
State
(Open Drain Output: ISINK = 1mA)
IOL
RESET Output Sink Current
VIN = 1.5V, VOL = 0.5V
VIN
Operating Input Voltage
Range
IIN
Quiescent Input Current
± 100
0.25
1.0
PPM/˚C
0.5
2.5
1.0
V
V
mA
6.0
V
20 Suffix
VIN = 1.9V
0.55
0.8
VIN = 4.0V
0.70
1.3
VIN = 2.87V
0.65
0.9
VIN = 5.0V
0.77
1.3
VIN = 4.34V
0.70
1.0
VIN = 6.0
0.85
1.4
60
300
30 Suffix
µA
45 Suffix
tp
Propagation Delay Time
Figure 1
µs
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Typical values represent the most likely parametric norm
Note 3: All limits are guaranteed by testing or statistical analysis.
3
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LM8364
Absolute Maximum Ratings
LM8364
Typical Performance Characteristics
Input Current vs. Input Voltage
LM8364BALMF45
Reset Output Voltage vs. Input Voltage
LM8364BALMF45
20065901
20065902
Reset Output Sink Current vs. Output Voltage
LM8364BALMF45
Reset Output Sink Current vs. Input Voltage
LM8364BALMF45
20065903
20065904
Detector Threshold Voltage vs. Temperature
LM8364BALMF45
20065905
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4
The propagation delay time for the LM8364 is measured
using a 470kΩ pull-up resistor connected to from the RESET
output pin to 5V in addition to a 10pF capacitive load con-
20065909
FIGURE 1. Propagation Delay Timing Diagrams
VHYS. This point is also known as VDET+ as indicated earlier.
This built-in hysteresis has been added to the design to help
prevent erratic reset operation when the input voltage
crosses the threshold.
The LM8364 ultra-low current voltage detector was designed
to monitor voltages and to provide an indication when the
monitored voltage, VIN, dropped below a precisely trimmed
threshold voltage. This characteristic is displayed in the typical operating timing diagram below. VIN is the voltage that is
being monitored and a pull up resistor is connected from the
RESET output pin to VIN. VIN is at some value above VDET+
and then begins to decrease. Since this is an Active Low
device the RESET output is pulled High through the pull-up
resistor and tracks VIN until VIN crosses the trimmed threshold VDET−. At this point the LM8364 recognizes that VIN is
now in a fault condition and the output immediately changes
to the Logic Low State. The RESET output will remain in this
low state until VIN increases above the threshold VDET− +
The LM8364 has a wide variety of applications that can take
advantage of its precision and low current consumption to
monitor Input voltages even though it was designed as a
reset controller in portable microprocessor based systems. It
is a very cost effective and space saving device that will
protect your more expensive investments of microprocessors and other devices that need a guaranteed supply voltage for proper operation.
20065910
FIGURE 2. Timing Waveforms
5
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LM8364
nected from the same pin to GND. Figure 1 shows the timing
diagram for the measurement for the propagation delay.
VDET+ is equal to the sum of the detector threshold, VDET−,
and the built in hysteresis, VHYS.
Application Notes
LM8364
Typical Applications
20065911
Microprocessor Reset Circuit
20065912
Dual Power Supply Undervoltage Supervision
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6
LM8364
Typical Applications
(Continued)
20065913
Microcontroller System Load Sensing
20065914
LED Bar Graph Voltage Monitor
7
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LM8364 Micropower Undervoltage Sensing Circuits
Physical Dimensions
inches (millimeters)
unless otherwise noted
5-Pin SOT23
NSC Package Number MF05A
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