LTC1841/LTC1842/LTC1843
Ultralow Power Dual
Comparators with Reference
FEATURES DESCRIPTION
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Ultralow Quiescent Current: 3.5A Typ The LTC 1841/LTC1842/LTC1843 are ultralow power dual
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Open-Drain Outputs Typically Sink comparators with built-in reference (LTC1842/LTC1843).
Greater Than 20mA The comparators feature less than 5.7A supply current
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Wide Supply Range: (LTC1841) over temperature, a 1.182V 1% reference, program-
Single: 2V to 11V mable hysteresis and open-drain outputs that sink cur-
Dual: 1V to 5.5V rent. The reference output can drive a bypass capacitor of
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Input Voltage Range Includes the Negative Supply up to 0.01F without oscillation.
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Reference Output Drives 0.01F Capacitor
The LTC1841 operates from a single 2V to 11V supply or
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Adjustable Hysteresis
a dual 1V to 5.5V supply. The LTC1842/LTC1843
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12s Propagation Delay with 10mV Overdrive
operate from a single 2.5V to 11V supply or a dual 1.25V
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No Current Spike When Switching
to 5.5V supply. The LTC1842/LTC1843 hysteresis is
easily programmed by using two resistors and the HYST
U
APPLICATIONS pin. The comparators input operates from the negative
supply to within 1.3V of the positive supply. The compara-
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Battery-Powered System Monitoring
tors output stage can typically sink greater than 20mA. By
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Threshold Detectors
eliminating the cross-conduction current that normally
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Window Comparators
happens when the comparators change logic states, power
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Oscillator Circuits
supply glitches are eliminated.
The LTC1841/LTC1842/LTC1843 are available in SO-8
, LTC and LT are registered trademarks of Linear Technology Corporation.
packages.
TYPICAL APPLICATION
Single Li-Ion Cell to 5V Supply
LTC1843 Supply Current
vs Supply Voltage
1-CELL
+ L1
R6
C1
Li-Ion
D1
10H
25k
100F
BATTERY 5
7
T = 25C
A
R1
67
V
CC LTC1843
OUTPUT
1.5M
V SW
4 IN B IN 5V
4
LT1302-5 Si9924DY 600mA
OUT B 8
3
SHDN I
T
8 4
+
PGND SENSE
R2
3
+
100k C2
V GND
C
100F
2 1
+ 2
3 IN A R
C
R7
+
20k
500k
OUT A 1
R3
C
C
1
1M
0.0F
6 REF
LBO
1841/43 TA01
0
C1, C2: SANYO OS-CON
R4
0 2 4 6 8 10 12
V HYST
20k D1: MOTOROLA MBRS130LT3
SUPPLY VOLTAGE (V)
L1: COILTRONICS CTX10-3
R5
25
1841/43 TA02
1.1M
1
SUPPLY CURRENT (A)
U
ULTC1841/LTC1842/LTC1843
ABSOLUTE MAXIMUM RATINGS
(Note 1)
+
OUT Short-Circuit Duration (V 5.5V) ...... Continuous
Voltage
+
Power Dissipation............................................. 500mW
V to V ................................................12V to 0.3V
+ +
IN , IN , HYST ................. (V + 0.3V) to (V 0.3V) Operating Temperature Range
+
LTC1841C/LTC1842C/LTC1843C ........... 0C to 70C
REF ................................... (V + 0.3V) to (V 0.3V)
LTC1841I/LTC1842I/LTC1843I .......... 40C to 85C
OUT ................................................ 12V to (V 0.3V)
Current Storage Temperature Range ................ 65C to 150C
+
Lead Temperature (Soldering, 10 sec).................. 300C
IN , IN , HYST ................................................. 20mA
REF ................................................................... 20mA
OUT .................................................................. 50mA
PACKAGE/ORDER INFORMATION
TOP VIEW TOP VIEW TOP VIEW
OUT A
OUT B
OUT A
1
8
OUT B
1
8
OUT A
1
8
OUT B
+ +
+
V
2
7
V
V
2
7
V
V 2
7
V
+ + + +
IN A
3
IN B
IN A
3
6
REF
IN A
3
6
REF
6
+
IN B 4 HYST
IN A 4 5
IN B 5
IN B 4 5
HYST
S8 PACKAGE
S8 PACKAGE
S8 PACKAGE
8-LEAD PLASTIC SO
8-LEAD PLASTIC SO 8-LEAD PLASTIC SO
T = 150C, = 125C/ W
T = 150C, = 125C/ W T = 150C, = 125C/ W
JMAX JA
JMAX JA JMAX JA
S8 PART
ORDER PART S8 PART ORDER PART
S8 PART ORDER PART
MARKING
NUMBER
NUMBER MARKING NUMBER MARKING
1843
LTC1841CS8 1841 LTC1842CS8 1842 LTC1843CS8
1843I
LTC1841IS8 1841I LTC1842IS8 1842I LTC1843IS8
Consult factory for Military grade parts.
+
ELECTRICAL CHARACTERISTICS V = 5V, V = 0V, T = 25C unless otherwise noted.
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply
+
V Supply Voltage Range LTC1841 l 2.0 11 V
LTC1842/LTC1843 l 2.5 11 V
I Supply Current HYST = REF (Note 2) l 3.5 5.7 A
CC
Comparator
V Comparator Input Offset Voltage (Note 3) l 3 10 mV
OS
+ +
I Input Leakage Current (IN , IN)IN = IN = 2.5V (LTC1841), l 0.01 1.0 nA
IN
+
IN = IN = V (LTC1842/LTC1843)
REF
+
V Comparator Input Voltage Range l V V 1.3V V
IN
+
PSRR Power Supply Rejection Ratio V = 2V to 11V (LTC1841), 0.1 1 mV/V
+
V = 2.5V to 11V (LTC1842/LTC1843)
+
CMRR Common Mode Rejection Ratio V = V to (V 1.3V) LTC1841 l 0.1 1 mV/V
CM
V Hysteresis Input Voltage Range LTC1842/LTC1843 l V 50mV V V
HYST REF REF
2
U
W U
W
U WW