LTC1440/LTC1441/LTC1442
Ultralow Power Single/Dual
Comparator with Reference
FEATURES
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DESCRIPTION
The LTC
®
1440/LTC1441/LTC1442 are ultralow power
single and dual comparators with built-in references. The
comparators feature less than 3.7µA supply current over
temperature (LTC1440), a 1.182V
±1%
reference, pro-
grammable hysteresis (LTC1440/LTC1442) and TTL/CMOS
outputs that sink and source current. The reference output
can drive a bypass capacitor of up to 0.01µF without
oscillation.
The comparators operate from a single 2V to 11V supply
or a dual
±1V
to
±5.5V
supply (LTC1440). Comparator
hysteresis is easily programmed by using two resistors
and the HYST pin (LTC1440/LTC1442). Each comparator’s
input operates from the negative supply to within 1.3V of
the positive supply. The comparator output stage can
continuously source up to 40mA. By eliminating the
cross-conducting current that normally happens when the
comparator changes logic states, the power supply glitches
are eliminated.
The LTC1440 is available in 8-pin PDIP, SO and MSOP
packages. The LTC1441/LTC1442 are available in 8-pin
PDIP and SO packages.
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Ultralow Quiescent Current: 2.1
µ
A Typ (LTC1440)
Wide Supply Range:
Single: 2V to 11V
Dual:
±1V
to
±5.5V
Input Voltage Range Includes the Negative Supply
Reference Output Drives 0.01
µ
F Capacitor
Adjustable Hysteresis (LTC1440/LTC1442)
TTL/CMOS Compatible Outputs
12µs Propagation Delay with 10mV Overdrive
No Crowbar Current
40mA Continuous Source Current
Pin Compatible Upgrades for MAX921/922/923
APPLICATIONS
s
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Battery-Powered System Monitoring
Threshold Detectors
Window Comparators
Oscillator Circuits
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Micropower 2.9V V
CC
Threshold Detector
3.3V
5.0
LTC1440 Supply Current vs Temperature
R1
1.65M
1%
R2
1.13M
1%
7
V
+
SUPPLY CURRENT (µA)
4.5
4.0
3.5
3.0
2.5
2.0
V
+
= 5V
V
–
= GND = 0V
3 IN
+
+
8
OUT
4 IN
–
–
5 HYST
LTC1440
6 REF
V
–
2
GND
1
1440 TA01
1.5
–40 –20
U
U
U
40
20
60
0
TEMPERATURE (°C)
80
100
1440/1/2 TA02
1
LTC1440/LTC1441/LTC1442
ABSOLUTE
MAXIMUM
RATINGS
Voltage
V
+
to V
–
, V
+
to GND, GND to V
–
...........12V to – 0.3V
IN
+
, IN
–
, HYST ................. (V
+
+ 0.3V) to (V
–
– 0.3V)
REF ................................... (V
+
+ 0.3V) to (V
–
– 0.3V)
OUT (LTC1440) .............. (V
+
+ 0.3V) to (GND – 0.3V)
OUT (LTC1441/LTC1442) ... (V
+
+ 0.3V) to (V
–
– 0.3V)
Current
IN
+
, IN
–
, HYST ................................................. 20mA
REF ................................................................... 20mA
OUT .................................................................. 50mA
OUT Short-Circuit Duration (V
+
≤
5.5V) ...... Continuous
Power Dissipation............................................. 500mW
Operating Temperature Range
LTC144XC .............................................. 0°C to 70°C
LTC144XI .......................................... – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
PACKAGE/ORDER INFORMATION
TOP VIEW
GND 1
V
–
2
IN
+
3
IN
–
4
N8 PACKAGE
8-LEAD PDIP
8
7
6
5
OUT
V
+
REF
HYST
ORDER PART NUMBER
LTC1440CN8
LTC1440CS8
LTC1440IN8
LTC1440IS8
S8 PART MARKING
1440
1440I
ORDER PART NUMBER
8
7
6
5
OUT B
V
+
+
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C,
θ
JA
= 175°C/ W (S8)
TOP VIEW
OUT A 1
V
IN A
–
+
2
3
IN B
IN A
–
4
N8 PACKAGE
8-LEAD PDIP
IN B
–
LTC1441CN8
LTC1441CS8
LTC1441IN8
LTC1441IS8
S8 PART MARKING
1441
1441I
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C,
θ
JA
= 175°C/ W (S8)
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Power Supply
V
+
Supply Voltage Range
I
CC
Supply Current
CONDITIONS
V
+
= 5V, V
–
= GND = 0V, T
A
= 25°C unless otherwise noted.
MIN
q
IN
+
= IN
–
= 80mV
HYST = REF (LTC1440/LTC1442)
2
U
U
W
W W
U
W
ORDER PART NUMBER
TOP VIEW
GND
V
–
IN
+
IN
–
1
2
3
4
8
7
6
5
OUT
V
+
REF
HYST
LTC1440CMS8
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 250°C/ W
MS8 PART MARKING
LTBX
ORDER PART NUMBER
TOP VIEW
OUT A 1
V
–
+
8
7
6
5
OUT B
V
+
2
3
IN A
REF
HYST
IN B
–
4
N8 PACKAGE
8-LEAD PDIP
LTC1442CN8
LTC1442CS8
LTC1442IN8
LTC1442IS8
S8 PART MARKING
1442
1442I
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C,
θ
JA
= 175°C/ W (S8)
TYP
MAX
11.0
3.7
5.7
5.7
UNITS
V
µA
µA
µA
2.0
2.1
3.5
3.5
LTC1440
LTC1441
LTC1442
q
q
q
LTC1440/LTC1441/LTC1442
ELECTRICAL CHARACTERISTICS
V
+
= 5V, V
–
= GND = 0V, T
A
= 25°C unless otherwise noted.
MIN
q
q
q
q
SYMBOL PARAMETER
CONDITIONS
Comparator
V
OS
Comparator Input Offset Voltage
V
CM
= 2.5V
+
, IN
–
)
Input Leakage Current (IN
V
IN +
= V
IN –
= 2.5V
I
IN
Input Leakage Current (HYST)
V
CM
Comparator Input Common Mode Range
CMRR
Common Mode Rejection Ratio
V
–
to V
+
– 1.3V
PSRR
Power Supply Rejection Ratio
V
+
= 2V to 11V
NOISE
Voltage Noise
100Hz to 100kHz
V
HYST
Hysteresis Input Voltage Range
LTC1440/LTC1442
t
PD
Propagation Delay
C
OUT
= 100pF
V
OH
V
OL
Output High Voltage
Output Low Voltage
I
O
= – 13mA
I
O
= 1.8mA
TYP
±3
±0.01
±0.02
MAX
±10
±1.0
±1.0
V
+
– 1.3V
1
1
REF
UNITS
mV
nA
nA
V
mV/V
mV/V
µV
RMS
V
µs
µs
V
V
V
V
V
V
µA
µA
mV
mV
mV
µV
RMS
V
–
0.1
0.1
100
q
REF – 50mV
15
8
Overdrive = 10mV
Overdrive = 100mV
q
V
+
– 0.4V
GND + 0.4V
V
–
+ 0.4V
1.170
1.164
1.164
100
10
1.182
1.194
1.200
1.200
LTC1440
LTC1441/LTC1442
q
q
q
q
q
q
q
q
Reference
V
REF
Reference Voltage
I
SOURCE
I
SINK
∆V
REF
Reference Output Source Current
Reference Output Sink Current
Reference Source Current
Reference Sink Current
Voltage Noise
No Load
C Temp Range
LTC1440/LTC1442
I Temp Range
No Load LTC1440 (MSOP) C Temp Range
∆V
REF
≤
1mV (LTC1442)
∆V
REF
≤
2.5mV (LTC1442)
0
≤
I
SOURCE
≤
2mA (LTC1440)
0
≤
I
SINK
≤
10µA (LTC1440)
100Hz to 100kHz
200
20
0.8
0.5
100
5
1.5
5
NOISE
V
+
= 3V, V
–
= GND = 0V, T
A
= 25°C unless otherwise noted.
Power Supply
V
+
Supply Voltage Range
I
CC
Supply Current
IN
+
= IN
–
= 80mV
HYST = REF (LTC1440/LTC1442)
Comparator
V
OS
Comparator Input Offset Voltage
Input Leakage Current (IN
+
, IN
–
)
I
IN
Input Leakage Current (HYST)
V
CM
Comparator Input Common Mode Range
CMRR
Common Mode Rejection Ratio
PSRR
Power Supply Rejection Ratio
NOISE
Voltage Noise
V
HYST
Hysteresis Input Voltage Range
t
PD
Propagation Delay
V
OH
V
OL
Output High Voltage
Output Low Voltage
q
2
2
3.5
3.5
±3
±0.01
±0.02
V
–
0.1
0.1
100
LTC1440
LTC1441
LTC1442
q
q
q
q
q
q
q
11
3.6
5.7
5.7
±10
±1
±1
+
– 1.3V
V
1
1
REF
V
µA
µA
µA
mV
nA
nA
V
mV/V
mV/V
µV
RMS
V
µs
µs
V
V
V
V
CM
= 1.5V
V
IN +
= V
IN –
= 1.5V
V
–
to V
+
– 1.3V
V
+
= 2V to 11V
100Hz to 100kHz
LTC1440/LTC1442
C
OUT
= 100pF
I
O
= – 8mA
I
O
= 0.8mA
q
REF – 50mV
14
5
Overdrive = 10mV
Overdrive = 100mV
q
V
+
– 0.4V
GND + 0.4V
V
–
+ 0.4V
LTC1440
LTC1441/LTC1442
q
q
3
LTC1440/LTC1441/LTC1442
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Reference
V
REF
Reference Voltage
CONDITIONS
No Load
C Temp Range
LTC1440/LTC1442
I Temp Range
No Load LTC1440 (MSOP) C Temp Range
∆V
REF
≤
1mV (LTC1442)
∆V
REF
≤
2.5mV (LTC1442)
0
≤
I
SOURCE
≤
1mA (LTC1440)
0
≤
I
SINK
≤
10µA (LTC1440)
100Hz to 100kHz
q
q
q
q
q
q
V
+
= 3V, V
–
= GND = 0V, T
A
= 25°C unless otherwise noted.
MIN
1.170
1.164
1.164
60
10
TYP
1.182
MAX
1.194
1.200
1.200
UNITS
V
V
V
µA
µA
mV
mV
mV
µV
RMS
I
SOURCE
I
SINK
∆V
REF
Reference Output Source Current
Reference Output Sink Current
Reference Source Current
Reference Sink Current
Voltage Noise
120
20
0.8
0.5
100
5.5
1.5
5
NOISE
The
q
denotes specifications which apply over the full operating
temperature range.
TYPICAL PERFORMANCE CHARACTERISTICS
Comparator Response Time vs
Input Overdrive
INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V)
4
3
2
1
0
T
A
= 25°C
OUTPUT VOLTAGE (V)
5
100mV
50mV
10mV
20mV
SINK CURRENT (mA)
INPUT VOLTAGE (mV)
0
100
–1
0
2
4
6
RESPONSE TIME (µs)
8
10
Comparator Short-Circuit Source
Current vs Supply Voltage
160
140
10
12
SOURCE CURRENT (mA)
RESPONSE TIME (µs)
100
80
60
40
20
0
0
1
OUT CONNECTED TO
V
–
= GND = 0V
8
RESPONSE TIME (µs)
120
3
SUPPLY VOLTAGE (V)
2
4
U W
1440/1/2 G01
Comparator Response Time vs
Input Overdrives
5
4
3
2
1
0
T
A
= 25°C
100mV
50mV
20mV
10mV
Comparator Short-Circuit Sink
Current vs Supply Voltage
200
180
160
140
120
100
80
60
40
20
0
OUT CONNECTED TO V
+
T
A
= 25°C
100
0
–1
0
2
4 6 8 10 12 14 16 18
RESPONSE TIME (µs)
1440/1/2 G02
0
1
2
3 4 5 6 7 8
SUPPLY VOLTAGE (V)
9
10
1440/1/2 G03
Comparator Response Time vs
Load Capacitance with 100mV
Input Overdrive
10000
Comparator Response Time at
Low Supply Voltage
t
PHL
1000
20mV OVERDRIVE
100
6
t
PLH
10
4
100mV OVERDRIVE
2
4
5
1440/1/2 G04
1
0
20
60
80
40
LOAD CAPACITANCE (nF)
100
1440/1/2 G05
1.0
1.1
1.2
1.3
1.4
SUPPLY VOLTAGE (V)
1.5
1.6
1440/1/2 G06
LTC1440/LTC1441/LTC1442
TYPICAL PERFORMANCE CHARACTERISTICS
Comparator Output Voltage High
vs Load Current
5
T
A
= 25°C
OUTPUT VOLTAGE HIGH (V)
OUTPUT VOLTAGE HIGH (V)
T
A
= 25°C
2.0
V
+
= 2V
V
+
= 5V
1.0
V
+
= 3V
POSITIVE-TO-NEGATIVE INPUT VOLTAGE (mV)
4
V
+
= 5V
3
V
+
= 3V
2
V
+
= 2V
1
0
10
20
30
40
LOAD CURRENT (mA)
50
60
LTC1440
Supply Current vs Temperature
6
1.190
5
SUPPLY CURRENT (µA)
REFERENCE OUTPUT VOLTAGE (V)
4
3
V
+
= 3V
V
–
= GND = 0V
2
V
+
= 5V
V
–
= GND = 0V
1
–60 –40 –20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
1440/1/2 G10
Reference Output Voltage vs
Output Load Current (Sink)
1.200
REFERENCE OUTPUT VOLTAGE (V)
1.195
REFERENCE VOLTAGE (V)
1.190
1.185
SINK
1.180
1.175
1.170
0
25
10
15
20
5
OUTPUT LOAD CURRENT (µA)
U W
1440/1/2 G07
Comparator Output Voltage Low
vs Load Current
2.5
80
60
LTC1440/LTC1442
Hysteresis Control
OUTPUT HIGH
40
20
0
–20
–40
–60
–80
0
10
20
30
V
REF
– V
HYST
(mV)
40
50
1440/1/2 G09
1.5
OUTPUT LOW
0.5
0
0
10
20 30 40 50 60
LOAD CURRENT (mA)
70
80
1440/1/2 G08
Reference Output Voltage vs
Output Load Current
V
CC
= 5V
1.185
SOURCE
1.180
1.175
1.170
1.165
1.160
1.155
0
0.5 1.0 1.5 2.0 2.5 3.0
OUTPUT LOAD CURRENT (mA)
3.5
V
+
= 5V
V
–
= –5V
1440/1/2 G11
Reference Voltage vs
Temperature
1.186
1.184
V
CC
= 2V
V
CC
= 5V
1.182
1.180
1.178
1.176
1.174
1.172
30
1.170
–60 –40 –20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
1440/1/2 G13
1440/1/2 G12
5
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