LMS33460
3V Under Voltage Detector
General Description
The LMS33460 is an under voltage detector with a 3.0V
threshold and extremely low power consumption. The
LMS33460 is specifically designed to accurately monitor
power supplies. It is especially suited to battery powered
systems where low quiescent current and small size are
required. This IC generates an active output whenever the
input voltage drops below 3.0 Volts.
This part uses a precision on-chip voltage reference and a
comparator to measure the input voltage. Built in hysteresis
helps to prevent erratic operation in the presence of noise.
The UVD is available in the ultra-miniature SC70-5 package.
Features
n
Ultra low Power
n
3.0V detection
n
V
IN
Range: 0.8V to 7.0V
n
Open drain output
n
Ultra-small SC70-5 package
n
Extended Temperature range (-40C to 85C)
n
Ultra Low Quiescent current (1A typ)
Applications
n
Low battery voltage detector
n
Power Fail Indicator
n
Processor Reset Generator
n
Battery Backup Control
n
Battery Operated Equipment
n
Hand-held Instruments
Circuit Block Diagram
20020001
Typical Application
20020003
March 2001
LMS33460
3V
Under
V
oltage
Detector
2004 National Semiconductor Corporation
DS200200
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Voltage to GND
8.0V
Output Voltage to GND
8.0V
Output Continuous Output Current
30mA
Vapor Phase IR Convection Reflow
240C
ESD Rating (Note 4)
Human Body Model
2500V
Machine Model
200V
T
JMAX
(Note 3)
150C
JA
(Note 3)
478C/W
Temperature Range
Operating Junction
-40C to +85C
Storage Temperature Range
-65C to +150C
Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
DET
Detector Threshold
V
IN
Falling
2.85
3.0
3.15
V
V
HYS
Detector Voltage Hysteresis
V
IN
Rising
0.095
0.155
0.215
V
I
IN
Input Supply Current
V
IN
= 2.87V
1.0
2.2
A
V
IN
= 4.7V
1.2
3.6
A
V
IN
= 7.0V (Note 3)
25
200
A
V
IN(MAX)
Maximum Operating Voltage
7.0
V
V
IN(MIN)
Maximum Operating Voltage
(Note 2)
0.7
1.0
1.1
1.3
V
I
OUT(LOW)
Output Current Low
V
OUT
= 0.05V, V
IN
= 1.1V
V
OUT
= 0.50V, V
IN
= 1.5V
0.01
2
0.6
11
mA
T
pdHL
Output Delay Time
Output Transition
High to Low
C
L
= 10pF, R
L
= 470k
70
130
sec
V
DET
/
T Detect Voltage Temperature
Coefficient
120
PPM/C
Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
beyond its rated operating conditions.
Note 2: Temperature range specifications is guaranteed by design.
Note 3: Quiescent current will increase substantially above 5.5 volts, but is very low in the normal range below 5.5 volts.
Note 4: Human body model, 1.5k
in series with 100pF. Machine model, 0 in series with 200pF.
LMS33460
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3
Typical Characteristics
(T
A
= 25C, R
L
= 470k
and C
L
= 10pF unless otherwise
noted).
Supply Current vs. Input Voltage
Detector Threshold vs. Temperature
20020004
20020005
Output Current vs. Input Voltage
Output Delay Time vs. Temperature
20020006
20020007
LMS33460
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4
Application Circuit Information
The LMS33460 is a micro power under voltage sensing
circuit with an open drain output configuration, which re-
quires a pull resistor.
The LMS33460 features a voltage reference, a comparator
with precise thresholds and built in hysteresis to prevent
erratic reset operation.
20020008
FIGURE 1. Propagation Delay
LMS33460
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