LTC1440IS8 [Linear]
Ultralow Power Single/Dual Comparator with Reference; 超低功耗单/双比较器与参考
| 型号： | LTC1440IS8 |
| 厂家： | 
Linear |
| 描述： | Ultralow Power Single/Dual Comparator with Reference |
| 文件： | 总12页 (文件大小：271K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTC1440/LTC1441/LTC1442
Ultralow Power Single/Dual
Comparator with Reference
U
FEATURES
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-
grammablehysteresis(LTC1440/LTC1442)andTTL/CMOS
outputsthatsinkandsourcecurrent. Thereferenceoutput
can drive a bypass capacitor of up to 0.01µF without
oscillation.
■
Ultralow Quiescent Current: 2.1µA Typ (LTC1440)
■
Wide Supply Range:
Single: 2V to 11V
Dual: ±1V to ±5.5V
■
Input Voltage Range Includes the Negative Supply
■
■
■
■
■
■
■
Reference Output Drives 0.01µF 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
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
andtheHYSTpin(LTC1440/LTC1442).Eachcomparator’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-conductingcurrentthatnormallyhappenswhenthe
comparatorchangeslogicstates,thepowersupplyglitches
are eliminated.
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APPLICATIONS
■
Battery-Powered System Monitoring
■
Threshold Detectors
■
Window Comparators
Oscillator Circuits
■
The LTC1440 is available in 8-pin PDIP, SO and MSOP
packages. The LTC1441/LTC1442 are available in 8-pin
PDIP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATION
Micropower 2.9V VCC Threshold Detector
LTC1440 Supply Current vs Temperature
3.3V
5.0
+
7
V
V
= 5V
R1
–
+
= GND = 0V
1.65M
4.5
4.0
3.5
3.0
2.5
2.0
1.5
V
1%
+
–
3
4
5
6
IN
+
–
8
R2
1.13M
1%
OUT
IN
HYST
REF
LTC1440
–
–40 –20
20
40
0
TEMPERATURE (°C)
60
80
100
GND
1
V
2
1440/1/2 TA02
1440 TA01
1
LTC1440/LTC1441/LTC1442
W W
U W
ABSOLUTE MAXIMUM RATINGS
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
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
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W U
PACKAGE/ORDER INFORMATION
TOP VIEW
ORDER PART NUMBER
ORDER PART NUMBER
TOP VIEW
GND
1
2
3
4
OUT
8
7
6
5
LTC1440CN8
LTC1440CS8
LTC1440IN8
LTC1440IS8
LTC1440CMS8
GND
1
2
3
4
8 OUT
7 V
6 REF
5 HYST
–
+
V
V
–
+
V
IN
+
–
+
IN
REF
IN
–
IN
HYST
MS8 PACKAGE
8-LEAD PLASTIC MSOP
N8 PACKAGE
S8 PACKAGE
MS8 PART MARKING
LTBX
S8 PART MARKING
8-LEAD PDIP 8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 250°C/ W
1440
1440I
TJMAX = 150°C, θJA = 130°C/ W (N8)
TJMAX = 150°C, θJA = 175°C/ W (S8)
ORDER PART NUMBER
ORDER PART NUMBER
TOP VIEW
TOP VIEW
OUT A
1
2
3
4
OUT B
8
7
6
5
OUT A
1
2
3
4
OUT B
8
7
6
5
LTC1442CN8
LTC1442CS8
LTC1442IN8
LTC1442IS8
LTC1441CN8
LTC1441CS8
LTC1441IN8
LTC1441IS8
–
+
–
+
V
V
V
V
+
+
+
IN A
REF
IN A
IN B
–
–
–
IN B
HYST
IN A
IN B
N8 PACKAGE
S8 PACKAGE
N8 PACKAGE
S8 PACKAGE
S8 PART MARKING
S8 PART MARKING
8-LEAD PDIP 8-LEAD PLASTIC SO
8-LEAD PDIP 8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 130°C/ W (N8)
TJMAX = 150°C, θJA = 175°C/ W (S8)
1442
1442I
1441
1441I
TJMAX = 150°C, θJA = 130°C/ W (N8)
T
JMAX = 150°C, θJA = 175°C/ W (S8)
Consult factory for Military grade parts.
V+ = 5V, V– = GND = 0V, TA = 25°C unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply
+
V
I
Supply Voltage Range
Supply Current
●
2.0
11.0
V
+
–
IN = IN = 80mV
LTC1440
LTC1441
LTC1442
●
●
●
2.1
3.5
3.5
3.7
5.7
5.7
µA
µA
µA
CC
HYST = REF (LTC1440/LTC1442)
2
LTC1440/LTC1441/LTC1442
V+ = 5V, V– = GND = 0V, TA = 25°C unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Comparator
CONDITIONS
MIN
TYP
MAX
UNITS
V
Comparator Input Offset Voltage
Input Leakage Current (IN , IN )
Input Leakage Current (HYST)
Comparator Input Common Mode Range
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
Propagation Delay
V
= 2.5V
CM
●
±3
±0.01
±0.02
±10
±1.0
±1.0
– 1.3V
1
1
mV
nA
nA
V
mV/V
mV/V
OS
+
–
+
–
I
V
IN
= V = 2.5V
●
●
IN
IN
–
+
V
CM
●
V
V
–
+
CMRR
PSRR
NOISE
V
V
to V – 1.3V
0.1
0.1
100
+
= 2V to 11V
100Hz to 100kHz
LTC1440/LTC1442
C
µV
RMS
V
HYST
●
●
REF – 50mV
REF
V
µs
µs
V
V
V
t
= 100pF
OUT
Overdrive = 10mV
Overdrive = 100mV
15
8
PD
+
V
V
Output High Voltage
Output Low Voltage
I = –13mA
I = 1.8mA
V
– 0.4V
OH
O
LTC1440
LTC1441/LTC1442
●
●
GND + 0.4V
OL
O
–
V
+ 0.4V
Reference
V
Reference Voltage
No Load
LTC1440/LTC1442
C Temp Range
I Temp Range
●
●
●
●
1.170
1.164
1.164
100
1.182
1.194
1.200
1.200
V
V
V
µA
µA
mV
mV
mV
REF
No Load LTC1440 (MSOP) C Temp Range
∆V ≤ 1mV (LTC1442)
I
I
Reference Output Source Current
Reference Output Sink Current
Reference Source Current
Reference Sink Current
200
20
0.8
0.5
SOURCE
SINK
REF
∆V ≤ 2.5mV (LTC1442)
10
REF
∆V
0 ≤ I
0 ≤ I
≤ 2mA (LTC1440)
SOURCE
●
●
5
1.5
5
REF
≤ 10µA (LTC1440)
SINK
NOISE
Voltage Noise
100Hz to 100kHz
100
µV
RMS
+
–
V
= 3V, V = GND = 0V, T = 25°C unless otherwise noted.
A
Power Supply
+
V
I
Supply Voltage Range
Supply Current
●
●
●
●
2
11
3.6
5.7
5.7
V
µA
µA
µA
+
–
IN = IN = 80mV
LTC1440
LTC1441
LTC1442
2
3.5
3.5
CC
HYST = REF (LTC1440/LTC1442)
Comparator
V
Comparator Input Offset Voltage
Input Leakage Current (IN , IN )
Input Leakage Current (HYST)
Comparator Input Common Mode Range
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage Range
Propagation Delay
V
V
= 1.5V
●
±3
±0.01
±0.02
±10
±1
±1
– 1.3V
1
1
mV
nA
nA
V
mV/V
mV/V
OS
CM
+
–
+
–
I
= V = 1.5V
●
●
IN
IN
IN
–
+
V
CM
●
V
V
–
+
+
CMRR
PSRR
NOISE
V
V
to V – 1.3V
0.1
0.1
100
= 2V to 11V
100Hz to 100kHz
LTC1440/LTC1442
C
µV
RMS
V
HYST
●
●
REF – 50mV
REF
V
µs
µs
V
V
V
t
= 100pF
OUT
Overdrive = 10mV
Overdrive = 100mV
14
5
PD
+
V
V
Output High Voltage
Output Low Voltage
I = –8mA
O
V
– 0.4V
OH
I = 0.8mA
O
LTC1440
LTC1441/LTC1442
●
●
GND + 0.4V
OL
–
V
+ 0.4V
3
LTC1440/LTC1441/LTC1442
+
–
ELECTRICAL CHARACTERISTICS
V
= 3V, V = GND = 0V, T = 25°C unless otherwise noted.
A
SYMBOL PARAMETER
Reference
CONDITIONS
MIN
TYP
MAX
UNITS
V
Reference Voltage
No Load
LTC1440/LTC1442
C Temp Range
I Temp Range
●
●
●
●
1.170
1.164
1.164
60
1.182
1.194
1.200
1.200
V
V
V
µA
µA
mV
mV
mV
REF
No Load LTC1440 (MSOP) C Temp Range
∆V ≤ 1mV (LTC1442)
I
I
Reference Output Source Current
Reference Output Sink Current
Reference Source Current
Reference Sink Current
120
20
0.8
0.5
SOURCE
SINK
REF
∆V ≤ 2.5mV (LTC1442)
10
REF
∆V
0 ≤ I
0 ≤ I
≤ 1mA (LTC1440)
SOURCE
●
●
5.5
1.5
5
REF
≤ 10µA (LTC1440)
SINK
NOISE
The
temperature range.
Voltage Noise
100Hz to 100kHz
100
µV
RMS
●
denotes specifications which apply over the full operating
U W
TYPICAL PERFORMANCE CHARACTERISTICS
Comparator Response Time vs
Input Overdrive
Comparator Response Time vs
Input Overdrives
Comparator Short-Circuit Sink
Current vs Supply Voltage
5
4
3
2
1
0
5
4
3
2
1
0
200
180
160
140
120
100
80
T
A
= 25°C
T
= 25°C
T = 25°C
A
A
100mV
50mV
10mV
20mV
50mV
100mV
20mV
+
10mV
OUT CONNECTED TO V
60
0
100
0
40
100
20
0
0
1
2
3
4
5
6
7
8
9
10
–1
0
2
8
10
–1
12 14 16 18
4
6
0
2
4
6
8
10
SUPPLY VOLTAGE (V)
RESPONSE TIME (µs)
RESPONSE TIME (µs)
1440/1/2 G03
1440/1/2 G01
1440/1/2 G02
Comparator Response Time vs
Load Capacitance with 100mV
Input Overdrive
Comparator Short-Circuit Source
Current vs Supply Voltage
Comparator Response Time at
Low Supply Voltage
12
10000
1000
100
10
160
140
120
100
80
10
8
t
PHL
OUT CONNECTED TO
–
V
= GND = 0V
20mV OVERDRIVE
100mV OVERDRIVE
t
PLH
6
60
40
4
20
0
1
2
1
2
4
20
60
LOAD CAPACITANCE (nF)
1.0
1.1
1.2
SUPPLY VOLTAGE (V)
1.3
1.4
1.5
1.6
0
5
0
40
80
100
3
SUPPLY VOLTAGE (V)
1440/1/2 G04
1440/1/2 G05
1440/1/2 G06
4
LTC1440/LTC1441/LTC1442
TYPICAL PERFORMANCE CHARACTERISTICS
U W
Comparator Output Voltage Low
vs Load Current
Comparator Output Voltage High
vs Load Current
LTC1440/LTC1442
Hysteresis Control
2.5
2.0
1.5
1.0
0.5
0
5
4
3
2
80
60
T
= 25°C
T
= 25°C
A
A
+
OUTPUT HIGH
V
= 5V
+
V
= 3V
40
+
V
= 2V
20
+
V
= 5V
0
+
OUTPUT LOW
–20
–40
–60
–80
V
= 3V
+
V
= 2V
20
1
0
10
30
40
50
60
0
30 40
50
80
0
10
20
– V
40
50
10 20
60 70
30
(mV)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
V
REF
HYST
1440/1/2 G07
1440/1/2 G08
1440/1/2 G09
LTC1440
Supply Current vs Temperature
Reference Output Voltage vs
Output Load Current
6
5
4
3
2
1.190
1.185
1.180
1.175
1.170
1.165
1.160
1.155
V
CC
= 5V
SOURCE
+
V
= 5V
–
V
= –5V
+
V
= 3V
–
V
= GND = 0V
+
–
V
V
= 5V
= GND = 0V
1
2.0
2.5
3.0
3.5
–60 –40 –20
0
20 40 60 80 100 120 140
0
0.5 1.0 1.5
TEMPERATURE (°C)
OUTPUT LOAD CURRENT (mA)
1440/1/2 G10
1440/1/2 G11
Reference Output Voltage vs
Output Load Current (Sink)
Reference Voltage vs
Temperature
1.186
1.184
1.182
1.180
1.178
1.176
1.174
1.172
1.170
1.200
1.195
1.190
1.185
1.180
1.175
1.170
V
= 2V
CC
V
= 5V
CC
SINK
–60 –40 –20
0
20 40 60 80 100 120 140
0
10
15
20
25
30
5
OUTPUT LOAD CURRENT (µA)
TEMPERATURE (°C)
1440/1/2 G13
1440/1/2 G12
5
LTC1440/LTC1441/LTC1442
U
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PIN FUNCTIONS
LTC1440
8
7
1
2
LTC1441
1
2
OUT A
LTC1442
1
OUT
OUT A
–
OUT B
OUT B
8
7
8
7
GND
–
V
2
+
+
–
+
B
A
V
V
V
V
V
A
B
+
–
+
+
+
+
–
–
–
–
+
REF
3
4
IN A
6
5
+
+
–
+
–
REF
3
4
IN
6
5
3
4
IN A
IN B
6
5
HYST
–
IN B
IN
IN A
–
–
HYST
V
IN B
1440/1/2 PD
IN B– (Pin 5): Inverting Input of Comparator B. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
IN B+ (Pin 6): Noninverting Input of Comparator B. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
LTC1440
GND (Pin 1): Ground. Connect to V– for single supply
operation.
V– (Pin 2): Negative Supply. Connect to ground for single
supply operation. Potential should be more negative than
GND.
IN+ (Pin 3): Noninverting Comparator Input. Input com-
mon mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
V+ (Pin 7): Positive Supply. 2V to 11V.
OUT B (Pin 8): Comparator B CMOS Output. Swings from
V– to V+. Output can source up to 40mA and sink 5mA.
IN– (Pin 4): Inverting Comparator Input. Input common
mode range from V– to V+ –1.3V. Input current typically
10pA at 25°C.
LTC1442
OUT A (Pin 1): Comparator A CMOS Output. Swings from
V– to V+. Output can source up to 40mA and sink 5mA.
HYST (Pin 5): Hysteresis Input. Connect to REF if not
used. Input voltage range is from VREF to VREF – 50mV.
V– (Pin 2): Negative Supply.
IN A+ (Pin 3): Noninverting Input of Comparator A. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
REF (Pin 6): Reference Output. 1.182V with respect
to V–. Can source up to 200µA and sink 15µA at 25°C.
Drive 0.01µF bypass capacitor without oscillation.
IN B– (Pin 4): Inverting Input of Comparator B. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
V+ (Pin 7): Positive Supply. 2V to 11V.
OUT (Pin 8): Comparator CMOS Output. Swings from
GND to V+. Output can source up to 40mA and sink 5mA.
HYST (Pin 5): Hysteresis Input. Connect to REF if not
used. Input voltage range is from VREF to VREF – 50mV.
LTC1441
REF (Pin 6): Reference Output. 1.182V with respect
to V–. Can source up to 200µA and sink 15µA at 25°C.
Drive 0.01µF bypass capacitor without oscillation.
V+ (Pin 7): Positive Supply. 2V to 11V.
OUT A (Pin 1): Comparator A CMOS Output. Swings from
V– to V+. Output can source up to 40mA and sink 5mA.
V– (Pin 2): Negative Supply.
IN A+ (Pin 3): Noninverting Input of Comparator A. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
OUT B (Pin 8): Comparator B CMOS Output. Swings from
V– to V+. Output can source up to 40mA and sink 5mA.
IN A– (Pin 4): Inverting Input of Comparator A. Input
common mode range from V– to V+ –1.3V. Input current
typically 10pA at 25°C.
6
LTC1440/LTC1441/LTC1442
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APPLICATIONS INFORMATION
LTC1440/LTC1441/LTC1442 are a family of micropower
comparators with built-in 1.182V reference. Features
include programmable hysteresis (LTC1440/LTC1442),
widesupplyvoltagerange(2Vto11V)andtheabilityofthe
reference to drive up to a 0.01µF capacitor without oscil-
lation. The comparators’ CMOS outputs can source up to
40mA and the supply current glitches, that normally occur
when switching logic states, have been eliminated.
capacitor of up to 0.01µF without oscillation and by
inserting a series resistor, capacitance values up to 100µF
can be used (Figure 1).
Figure 2 shows the resistor value required for different
capacitor values to achieve critical damping. Bypassing
the reference can help prevent false tripping of the com-
parators by preventing glitches on V+ or reference load
transients from disturbing the reference output voltage.
Power Supplies
Figure 3 shows the bypassed reference output with a
squarewaveappliedtotheV+ pin. ResistorsR2andR3set
10mV of hysteresis voltage band while R1 damps the
reference response. Note that the comparator output
doesn’t trip.
The comparator family operates from a single 2V to 11V
supply. The LTC1440 includes a separate ground for the
comparator output stage, allowing a split supply ranging
from±1Vto±5.5V.ConnectingV– toGNDontheLTC1440
will allow single supply operation. If the comparator out-
put is required to source more than 1mA, or the supply
source impedance is high, V+ should be bypassed with a
0.1µF capacitor.
REFERENCE
OUTPUT
REF
R1
LTC144X
Comparator Inputs
C1
–
V
The comparator inputs can swing from the negative sup-
ply V– to within 1.3V max of the positive supply V+. The
inputscanbeforced300mVbelowV– oraboveV+ without
damage and the typical input leakage current is only
±10pA.
1440/1/2 F01
Figure 1. Damping the Reference Output
Comparator Outputs
1000
100
10
The LTC1440 comparator output swings between GND
and V+ to assure TTL compatibility with a split supply. The
LTC1441andLTC1442outputsswingbetweenV– andV+.
The outputs are capable of sourcing up to 40mA and
sinking up to 5mA while still maintaining microampere
quiescent currents. The output stage does not generate
crowbarswitchingcurrentsduringtransitionswhichhelps
minimize parasitic feedback through the supply pins.
1
Voltage Reference
0.1
0.001
0.01
0.1
1
10
CAPACITOR VALUE (µF)
The internal bandgap reference has a voltage of 1.182V
referenced to V–. The reference accuracy is 1.5% from
–40°C to 85°C. It can source up to 200µA and sink up to
20µA with a 5V supply. The reference can drive a bypass
1440/1/2 F02
Figure 2. Damping Resistance vs Bypass Capacitor Value
7
LTC1440/LTC1441/LTC1442
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APPLICATIONS INFORMATION
up to 15%. If hysteresis is not wanted, the HYST pin
shouldbeshortedtoREF. AcceptablevaluesforIREF range
from0.1µAto5µA. If2.4MischosenforR2, thenthevalue
of R1 is equal to the value of VHB.
7
+
V
+
3
4
5
6
IN
IN
+
–
8
OUT
–
5V
TO
8V
V
HB
HYST
REF
R1 =
R2 =
6
5
REF
(2)(I
)
I
REF
REF
R2
10k
LTC1440
R1
R2
LTC1440
V
HB
2
1.182V –
(
)
HYST
I
–
REF
R3
2.4M
R1
430Ω
V
–
GND
1
V
2
2
C1
1µF
1440/1/2 F04
1440/1/2 F03a
Figure 4. Programmable Hysteresis
Figure 3a. Reference Transient Response Test Circuit
Level Detector
The LTC1440 is ideal for use as a micropower level
detector as shown in Figure 5. R1 and R2 form a voltage
divider from VIN to the noninverting comparator input. R3
and R4 set the hysteresis voltage, and R5 and C1 bypass
the reference output. The following design procedure can
be used to select the component values:
8V
V+
5V
VREF
OUT
1. Choose the VIN voltage trip level, in this example 4.65V.
2ms/DIV
1440/1/2 F03b
V
IN
5V
R2
3.4M
1%
7
Figure 3b. Reference and Comparator Output
Transient Response
+
V
+
–
3
4
5
6
IN
IN
+
–
8
R1
1.18M
1%
OUT
Hysteresis
Hysteresis can be added to the LTC1440 by connecting a
resistor (R1) between the REF and HYST pins and a
second resistor (R2) from HYST to V– (Figure 4).
HYST
REF
R3
15k
1%
LTC1440
The difference between the upper and lower threshold
voltages,orhysteresisvoltageband(VHB),isequaltotwice
the voltage difference between the REF and HYST pins.
R4
2.4M
1%
R5
430Ω
5%
C1
1µF
–
GND
1
V
2
When more hysteresis is added, the upper threshold
increases the same amount as the low threshold de-
creases. The maximum voltage allowed between REF and
HYST pins is 50mV, producing a maximum hysteresis
voltagebandof100mV. Thehysteresisbandcouldvaryby
1440/1/2 F05
Figure 5. Glitch-Free Level Detector with Hysteresis
8
LTC1440/LTC1441/LTC1442
U
W U U
APPLICATIONS INFORMATION
2. Calculate the required resistive divider ratio.
Ratio = VREF/VIN
4.65V
R2 = 1.18M
−1
15mV
2
Ratio = 1.182V/4.65V = 0.254
1.182V +
3. Choose the required hysteresis voltage band at the
inputVHBIN,inthisexample60mV.Calculatethehyster-
esis voltage band referred to the comparator input VHB.
R2 = 3.40M
Low Voltage Operation
V
HB = (VHBIN)(Ratio)
The guaranteed minimum operating voltage is 2V or
(±1V). Asthetotalsupplyvoltageisreducedbelow2V, the
performance degrades and the supply current falls. Both
the reference and the comparator are still functioning with
supply voltage down to 1.5V. The reference will have
slightly worse temperature coefficient. While the com-
parator would have less output drive and the propagation
delay increases. The useful input voltage range extends
from the negative supply to a little under 1V below the
positive supply, which is slightly closer to the positive rail
than the device operating from higher supply voltages.
VHB = (60mV)(0.254)
VHB = 15.24mV
4. Choose the values for R3 and R4 to set the hysteresis.
R4 = 2.4M
R3(kΩ) = VHB = 15k
5. Choose the values for R1 and R2 to set the trip point.
V
1.182V
1µA
REF
R1=
=
= 1.18M
−1
I
BIAS
V
IN
R2 = R1
V
2
HB
V
+
REF
U
TYPICAL APPLICATIONS
Low Battery Detect Operates Down to 1.5V
7
+
2-CELL
NiCd
V
LTC1440
2.6M
1M
+
–
3
4
IN
+
–
8
OUT
IN
+
V
6
5
REF
20k
HYST
–
V
GND
1
1440 TA06
1.3M
1M
2
9
LTC1440/LTC1441/LTC1442
U
TYPICAL APPLICATIONS
10-Bit 30µA A/D Converter
32.768kHz
1M
5V
470k
+
C2
1/2 LTC1441
5V
E
IN
–
0V TO 3V
1.2M
LT®1034
1.2V
100k
10pF
365k*
+
C1
STATUS
1/2 LTC1441
2N3809
–
VN2222LL
1N914
10M
0.033µF
POLYSTYRENE
DATA
OUT
74C00
74C00
74C00
150k
Q
D
Q
74C74
74C00
CLK
CONV
COMMAND
1440/1/2 TA03
*TRW-IRC MRT–5/+120ppm/°C
32.768kHz “Watch Crystal” Oscillator
32.768kHz
1M
+V
470k
+
1/2
LTC1441
OUT
–
1.2M
10pF
1440/1/2 TA05
10
LTC1440/LTC1441/LTC1442
U
Dimensions in inches (millimeters) unless otherwise noted.
PACKAGE DESCRIPTION
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.400*
(10.160)
MAX
8
7
6
5
4
0.255 ± 0.015*
(6.477 ± 0.381)
1
2
3
0.130 ± 0.005
0.300 – 0.325
0.045 – 0.065
(3.302 ± 0.127)
(1.143 – 1.651)
(7.620 – 8.255)
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
0.125
(3.175)
MIN
0.005
(0.127)
MIN
0.015
+0.025
–0.015
(0.380)
MIN
0.325
+0.635
8.255
(
)
–0.381
0.100 ± 0.010
(2.540 ± 0.254)
0.018 ± 0.003
(0.457 ± 0.076)
N8 0695
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
7
5
8
6
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
3
4
2
0.010 – 0.020
(0.254 – 0.508)
× 45°
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
0.008 – 0.010
(0.203 – 0.254)
0°– 8° TYP
0.016 – 0.050
0.406 – 1.270
0.050
(1.270)
BSC
0.014 – 0.019
(0.355 – 0.483)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
SO8 0695
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
11
LTC1440/LTC1441/LTC1442
U
TYPICAL APPLICATION
10kHz V/F Converter
+V
6.2V TO 12V
LM334
2k*
Q8
Q1
+
LT1034-1.2
LT1034-1.2
2.2µF
10kHz TRIM
200k
+
1.2M*
INPUT
0V TO 5V
0.47µF
–
C1
0.01µF
1/2 LTC1441
Q2
Q3
Q4
+
50pF
100k
2M TYP
100Hz TRIM
= HP5082-2810
= 1N4148
15k
Q7
Q5
= 2N2222
100pF**
10M
f
OUT
0kHz TO 10kHz
= 1% METAL FILM
= POLYSTYRENE
*
**
74C14
Q6
2.7M
0.1µF
–
C2
1/2 LTC1441
1440/1/2 TA04
+
RELATED PARTS
PART NUMBER
LT1178/LT1179
LT1351
DESCRIPTION
COMMENTS
Dual/Quad 17µA Precision Single Supply Op Amps
Single 250µA, 3MHz, 200V/µs Op Amp with Shutdown
Dual/Quad 250µA, 3MHz, 200V/µs Op Amps
70µV Max V , 5nA Max I
OS BIAS
C-LoadTM Op Amp Stable Driving Any Capacitive Load
LT1352/LT1353
C-LoadOp Amps Stable Driving Any Capacitive Load
LTC1443/LTC1444/LTC1445 Micropower Quad Comparator with 1% Reference
LTC1443 Has 1.182V Reference, LTC1444/LTC1445 Have
1.221V Reference and Adjustable Hysteresis
C-Load is a trademark of Linear Technology Corporation.
144012fa LT/TP 0298 REV A 2K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1996
Linear Technology Corporation
●
1630McCarthyBlvd.,Milpitas, CA95035-7417 (408)432-1900
12
●
●
FAX: (408) 434-0507 TELEX: 499-3977 www.linear-tech.com
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