LTC1440IMS8#TR [Linear]
LTC1440 - Ultralow Power Single/Dual Comparator with Reference; Package: MSOP; Pins: 8; Temperature Range: -40°C to 85°C;
| 型号： | LTC1440IMS8#TR |
| 厂家： | 
Linear |
| 描述： | LTC1440 - Ultralow Power Single/Dual Comparator with Reference; Package: MSOP; Pins: 8; Temperature Range: -40°C to 85°C 放大器 光电二极管 |
| 文件： | 总16页 (文件大小：228K) |
| 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
DESCRIPTIO
FEATURES
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: 2.1
µ
A Typ (LTC1440)
■
Reference Output Drives 0.01
µF Capacitor
■
■
Adjustable Hysteresis (LTC1440/LTC1442)
Wide Supply Range:
Single: 2V to 11V
Dual: ±1V to ±5.5V
■
■
■
■
■
■
■
Input Voltage Range Includes the Negative Supply
TTL/CMOS Compatible Outputs
12µs Propagation Delay with 10mV Overdrive
No Crowbar Current
40mA Continuous Source Current
Pin Compatible Upgrades for MAX921/922/923
3mm x 3mm x 0.75mm DFN Package (LTC1440)
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.
U
APPLICATIO S
■
Battery-Powered System Monitoring
■
Threshold Detectors
■
Window Comparators
Oscillator Circuits
■
The LTC1440 is available in 8-pin PDIP, SO, MSOP and
DFN packages. The LTC1441/LTC1442 are available in
8-pin PDIP and SO packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
U
TYPICAL APPLICATIO
Micropower 2.9V V Threshold Detector
CC
LTC1440 Supply Current vs Temperature
3.3V
5.0
+
V
V
= 5V
–
7
= GND = 0V
4.5
4.0
3.5
3.0
2.5
2.0
1.5
R1
1.65M
1%
+
V
+
–
3
4
5
6
IN
IN
+
–
8
R2
1.13M
1%
OUT
HYST
REF
LTC1440
40
0
TEMPERATURE (°C)
80 100
–40 –20
20
60
–
GND
1
V
1440/1/2 TA02
2
1440 TA01
144012fd
1
LTC1440/LTC1441/LTC1442
W W
ABSOLUTE MAXIMUM RATINGS
(Note 1)
U W
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
Storage Temperature Range
(DD Package) ................................... –65°C to 125°C
Junction Temperature........................................... 150°C
Junction Temperature (DD Package) .................... 125°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
U
W U
PACKAGE/ORDER INFORMATION
TOP VIEW
TOP VIEW
GND
1
2
3
4
8
7
6
5
OUT
TOP VIEW
GND
1
2
3
4
OUT
8
7
6
5
–
+
V
V
GND
1
2
3
4
8 OUT
7 V
6 REF
5 HYST
–
+
V
V
–
+
+
V
IN
IN
REF
+
–
+
IN
REF
–
IN
HYST
IN
–
IN
HYST
MS8 PACKAGE
8-LEAD PLASTIC MSOP
DD PACKAGE
N8 PACKAGE
8-LEAD PDIP 8-LEAD PLASTIC SO
S8 PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
TJMAX = 150°C, θJA = 250°C/ W
TJMAX = 125°C, θJA = 160°C/ W (DD)
UNDERSIDE METAL CONNECTED TO V–
(PCB CONNECTION OPTIONAL)
TJMAX = 150°C, θJA = 130°C/ W (N8)
T
JMAX = 150°C, θJA = 175°C/ W (S8)
S8 PART
DD8 PART
MARKING*
LBTH
ORDER PART
NUMBER
LTC1440CDD
LTC1440IDD
ORDER PART
NUMBER
LTC1440CN8
LTC1440CS8
LTC1440IN8
LTC1440IS8
MS8 PART
MARKING*
LTBX
ORDER PART
NUMBER
LTC1440CMS8
LTC1440IMS8
MARKING
1440
1440
1440I
1440I
ORDER PART
NUMBER
ORDER PART
NUMBER
LTC1441CN8
LTC1441CS8
LTC1441IN8
LTC1441IS8
TOP VIEW
TOP VIEW
OUT A
1
2
3
4
OUT B
OUT A
1
2
3
4
OUT B
8
7
6
5
8
7
6
5
LTC1442CN8
LTC1442CS8
LTC1442IN8
LTC1442IS8
–
+
–
+
V
V
V
V
+
+
+
IN A
REF
IN A
IN B
–
–
–
IN B
HYST
IN A
IN B
S8 PART
S8 PART
N8 PACKAGE
S8 PACKAGE
N8 PACKAGE
S8 PACKAGE
8-LEAD PDIP 8-LEAD PLASTIC SO
8-LEAD PDIP 8-LEAD PLASTIC SO
MARKING
MARKING
TJMAX = 150°C, θJA = 130°C/ W (N8)
TJMAX = 150°C, θJA = 175°C/ W (S8)
T
T
JMAX = 150°C, θJA = 130°C/ W (N8)
JMAX = 150°C, θJA = 175°C/ W (S8)
1441
1441I
1442
1442I
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
* The temperature grade is identified by a label on the shipping container.
144012fd
2
LTC1440/LTC1441/LTC1442
ELECTRICAL CHARACTERISTICS
The
●
+
denotes the specifications which apply over the full operating
–
temperature range, otherwise specifications are at T = 25
°
C. V = 5V and V = GND = 0V unless otherwise noted.
A
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply
+
V
I
Supply Voltage Range
Supply Current
●
2.0
11.0
4.0
4.4
V
µA
µA
+
–
IN = IN + 80mV
LTC1440 0°C ≤ T ≤ 70°C
●
●
2.1
CC
A
HYST = REF (LTC1440/LTC1442)
–40°C ≤ T ≤ 85°C
A
LTC1441
LTC1442
●
●
3.5
3.5
5.7
5.7
µA
µA
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
V
V
= 2.5V
CM
●
±3
±0.01
±0.02
± 10
±1.0
±1.0
– 1.3V
1
1
1
mV
nA
nA
OS
+
–
+
–
I
= V = 2.5V
●
●
IN
IN
IN
–
+
V
●
V
V
V
CM
–
+
CMRR
PSRR
V
V
V
to V – 1.3V
0.1
0.1
0.1
mV/V
mV/V
mV/V
+
+
= 2V to 11V (LTC1441)
= 2.5V to 11V (LTC1440/LTC1442)
NOISE
Voltage Noise
Hysteresis Input Voltage Range
Propagation Delay
100Hz to 100kHz
LTC1440/LTC1442
100
µV
RMS
V
µs
µs
V
V
V
V
●
●
REF – 50mV
REF
HYST
t
C
= 100pF
Overdrive = 10mV
15
8
PD
OUT
Overdrive = 100mV
+
V
V
Output High Voltage
Output Low Voltage
I = –13mA
V
– 0.4V
OH
OL
O
I = 1.8mA
O
LTC1440
LTC1441/LTC1442
●
●
GND + 0.4V
–
V
+ 0.4V
Reference
V
Reference Voltage
No Load
LTC1440/LTC1442
REF
0°C ≤ T ≤ 70°C
●
●
1.170
1.164
1.194
1.200
V
V
A
–40°C ≤ T ≤ 85°C
A
LTC1440 (MSOP, DFN)
●
●
1.164
100
10
1.200
V
µA
µA
mV
mV
mV
I
I
Reference Output Source Current ∆V ≤ 1mV (LTC1442)
REF
SOURCE
SINK
Reference Output Sink Current
Reference Source Current
Reference Sink Current
∆V ≤ 2.5mV (LTC1442)
20
0.8
0.5
REF
∆V
0 ≤ I
≤ 2mA (LTC1440)
●
●
5
1.5
5
REF
SOURCE
0 ≤ I
≤ 10µA (LTC1440)
SINK
NOISE
Voltage Noise
100Hz to 100kHz
100
µV
RMS
144012fd
3
LTC1440/LTC1441/LTC1442
ELECTRICAL CHARACTERISTICS The
●
+
denotes the specifications which apply over the full operating
–
temperature range, otherwise specifications are at T = 25
°
C. V = 3V and V = GND = 0V unless otherwise noted.
A
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply
+
V
Supply Voltage Range
●
2
11
V
+
–
I
Supply Current
IN = IN + 80mV
LTC1440 0°C ≤ T ≤ 70°C
●
●
2
3.9
4.3
µA
µA
CC
A
HYST = REF (LTC1440/LTC1442)
–40°C ≤ T ≤ 85°C
A
LTC1441
LTC1442
●
●
3.5
3.5
5.7
5.7
µA
µA
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
V
V
= 1.5V
●
±3
±0.01
±0.02
±10
±1
±1
– 1.3V
1
1
1
mV
nA
nA
OS
CM
+
–
+
–
I
= V = 1.5V
●
●
IN
IN
IN
–
+
V
CM
●
V
V
V
–
+
CMRR
PSRR
V
V
V
to V – 1.3V
0.1
0.1
0.1
mV/V
mV/V
mV/V
+
+
= 2V to 11V (LTC1441)
= 2.5V to 11V (LTC1440/LTC1442)
NOISE
Voltage Noise
Hysteresis Input Voltage Range
Propagation Delay
100Hz to 100kHz
LTC1440/LTC1442
100
µV
RMS
V
µs
µs
V
HYST
●
●
REF – 50mV
REF
t
C
OUT
= 100pF
Overdrive = 10mV
Overdrive = 100mV
14
5
PD
+
V
OH
Output High Voltage
I = –8mA
O
V
– 0.4V
V
Comparator
V
OL
Output Low Voltage
I = 0.8mA
O
LTC1440
LTC1441/LTC1442
●
●
GND + 0.4V
V
V
–
V
+ 0.4V
Reference
V
REF
Reference Voltage
No Load
LTC1440/LTC1442
0°C ≤ T ≤ 70°C
●
●
1.170
1.164
1.182
1.194
1.200
V
V
A
–40°C ≤ T ≤ 85°C
A
LTC1440 (MSOP, DFN)
●
●
1.164
60
10
1.200
V
µA
µA
I
I
Reference Output Source Current ∆V ≤ 1mV (LTC1442)
120
20
SOURCE
SINK
REF
Reference Output Sink Current
Reference Source Current
Reference Sink Current
∆V ≤ 2.5mV (LTC1442)
REF
∆V
0 ≤ I
0 ≤ I
≤ 1mA (LTC1440)
≤ 10µA (LTC1440)
●
●
0.8
0.5
5.5
1.5
5
mV
mV
mV
REF
SOURCE
SINK
NOISE
Voltage Noise
100Hz to 100kHz
100
µV
RMS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
144012fd
4
LTC1440/LTC1441/LTC1442
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Comparator Response Time vs
Comparator Response Time vs
Input Overdrive
Input Overdrive
5
5
T
= 25°C
A
T
A
= 25°C
100mV
50mV
10mV
20mV
4
3
2
1
0
4
3
2
1
0
50mV
100mV
20mV
10mV
0
100
0
100
–1
0
2
8
10
–1
12 14 16 18
4
6
0
2
4
6
8
10
RESPONSE TIME (µs)
RESPONSE TIME (µs)
1440/1/2 G01
1440/1/2 G02
Comparator Short-Circuit Sink
Current vs Supply Voltage
Comparator Short-Circuit Source
Current vs Supply Voltage
200
180
160
140
120
100
80
160
140
120
100
80
T
= 25°C
A
+
OUT CONNECTED TO V
OUT CONNECTED TO
–
V
= GND = 0V
60
60
40
40
20
20
0
0
0
1
2
3
4
5
6
7
8
9
10
0
1
2
4
5
3
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
1440/1/2 G03
1440/1/2 G04
144012fd
5
LTC1440/LTC1441/LTC1442
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Comparator Response Time vs
Load Capacitance with 100mV
Input Overdrive
Comparator Response Time at
Low Supply Voltage
12
10000
1000
100
10
10
8
t
PHL
20mV OVERDRIVE
100mV OVERDRIVE
t
PLH
6
4
2
1
0
20
40
60
80
100
1.0
1.1
1.2
1.3
1.4
1.5
1.6
LOAD CAPACITANCE (nF)
SUPPLY VOLTAGE (V)
1440/1/2 G05
1440/1/2 G06
Comparator Output Voltage High
vs Load Current
5
4
3
2
T
= 25°C
A
+
V
= 5V
+
V
= 3V
+
V
= 2V
20
1
0
10
30
40
50
60
LOAD CURRENT (mA)
1440/1/2 G07
144012fd
6
LTC1440/LTC1441/LTC1442
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Comparator Output Voltage Low
vs Load Current
LTC1440/LTC1442
Hysteresis Control
80
2.5
T
= 25°C
A
60
OUTPUT HIGH
2.0
1.5
1.0
0.5
0
+
V
= 3V
40
20
0
+
V
= 2V
+
V
= 5V
OUTPUT LOW
–20
–40
–60
–80
40
LOAD CURRENT (mA)
0
10
20
– V
40
50
0
10 20 30
50 60 70 80
30
(mV)
V
REF
HYST
1440/1/2 G08
1440/1/2 G09
LTC1440
Supply Current vs Temperature
6
5
4
3
2
+
V
= 5V
–
V
= –5V
+
–
V
V
= 3V
= GND = 0V
+
–
V
V
= 5V
= GND = 0V
1
–60 –40 –20
0
20 40 60 80 100 120 140
TEMPERATURE (°C)
1440/1/2 G10
144012fd
7
LTC1440/LTC1441/LTC1442
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Reference Output Voltage vs
Output Load Current (Sink)
Reference Output Voltage vs
Output Load Current
1.190
1.200
1.195
1.190
1.185
1.180
1.175
1.170
V
CC
= 5V
V
= 2V
CC
1.185
1.180
1.175
1.170
1.165
1.160
1.155
SOURCE
V
= 5V
CC
SINK
0
10
15
20
25
30
5
2.0
3.0 3.5
0
0.5 1.0 1.5
2.5
OUTPUT LOAD CURRENT (µA)
OUTPUT LOAD CURRENT (mA)
1440/1/2 G12
1440/1/2 G11
Reference Voltage vs
Temperature
1.186
1.184
1.182
1.180
1.178
1.176
1.174
1.172
1.170
–60 –40 –20
0
20 40 60 80 100 120 140
TEMPERATURE (°C)
1440/1/2 G13
144012fd
8
LTC1440/LTC1441/LTC1442
U
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
IN B
6
5
HYST
–
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.
144012fd
9
LTC1440/LTC1441/LTC1442
U
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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
144012fd
10
LTC1440/LTC1441/LTC1442
U
W U U
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
–
V
(2)(I
5V
TO
8V
HB
HYST
REF
R1 =
R2 =
6
5
REF
)
I
REF
REF
R2
10k
LTC1440
R1
R2
LTC1440
V
2
HB
1.182V –
(
)
HYST
I
–
REF
V
R3
2.4M
R1
430Ω
–
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
V
REF
1. Choose the VIN voltage trip level, in this example 4.65V.
OUT
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
144012fd
11
LTC1440/LTC1441/LTC1442
U
W U U
APPLICATIONS INFORMATION
2. Calculate the required resistive divider ratio.
⎡
⎢
⎢
⎢
⎤
⎥
Ratio = VREF/ VIN
4.65
V
⎥
R2 = 1.18M
R2 = 3.40M
− 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.
Low Voltage Operation
V
HB = (VHBIN)(Ratio)
VHB = (60mV)(0.254)
HB = 15.24mV
It is important to note that the voltage references internal
to the LTC1440 and LTC1442 can exceed the common
mode range of the comparators at low supply voltages.
The input common mode range of the LTC1440/LTC1441/
LTC1442 comparators is guaranteed to extend up to (V+ -
1.3V). Therefore, if one of the comparator inputs is at the
1.182V reference voltage, the minimum supply voltage is
2.5V for a valid output reading.
V
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.
The guaranteed minimum operating voltage for the
LTC1440/LTC1441/LTC1442 is 2V (or ±1V). However,
both the reference and comparator(s) will function with a
supply voltage as low as 1.5V, but performance will
degrade as the voltage goes below 2V. The voltage refer-
ence temperature coefficient will degrade slightly, and the
comparatorswillhavelessoutputdrivewithanincreasein
propagation delay. At the reduced supply voltages, the
input common mode range of the comparator(s) will still
typicallyextendfromthenegativesupplytoapproximately
1.1V below the positive supply.
V
1.182V
1µA
REF
R1=
=
= 1.18M
I
BIAS
⎡
⎤
⎥
⎢
V
IN
⎢
⎥
R2 = R1
− 1
V
2
⎢
⎣
⎥
HB
V
+
REF
⎢
⎥
⎦
144012fd
12
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
Q
74C74
74C00
D
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
144012fd
13
LTC1440/LTC1441/LTC1442
U
PACKAGE DESCRIPTIO
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
R = 0.115
0.38 ± 0.10
TYP
5
8
0.675 ±0.05
3.5 ±0.05
2.15 ±0.05 (2 SIDES)
1.65 ±0.05
3.00 ±0.10
(4 SIDES)
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
(NOTE 6)
PACKAGE
OUTLINE
(DD8) DFN 1203
4
1
0.25 ± 0.05
0.75 ±0.05
0.200 REF
0.25 ± 0.05
0.50 BSC
0.50
BSC
2.38 ±0.05
(2 SIDES)
2.38 ±0.10
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
0.889 ± 0.127
(.035 ± .005)
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.52
(.0205)
REF
0.65
(.0256)
BSC
0.42 ± 0.038
8
7 6
5
(.0165 ± .0015)
TYP
RECOMMENDED SOLDER PAD LAYOUT
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
4.90 ± 0.152
(.193 ± .006)
DETAIL “A”
0° – 6° TYP
0.254
(.010)
GAUGE PLANE
1
2
3
4
0.53 ± 0.152
(.021 ± .006)
1.10
(.043)
MAX
0.86
(.034)
REF
DETAIL “A”
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
0.127 ± 0.076
(.009 – .015)
(.005 ± .003)
0.65
(.0256)
BSC
TYP
MSOP (MS8) 0204
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
144012fd
14
LTC1440/LTC1441/LTC1442
U
PACKAGE DESCRIPTION
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
.400*
(10.160)
MAX
8
7
6
5
4
.255 ± .015*
(6.477 ± 0.381)
1
2
3
.130 ± .005
.300 – .325
.045 – .065
(3.302 ± 0.127)
(1.143 – 1.651)
(7.620 – 8.255)
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
.120
.020
(0.508)
MIN
(3.048)
MIN
+.035
.325
–.015
.018 ± .003
(0.457 ± 0.076)
.100
(2.54)
BSC
+0.889
8.255
(
)
N8 1002
–0.381
NOTE:
INCHES
1. DIMENSIONS ARE
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
.050 BSC
7
5
8
6
.245
MIN
.160 ±.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
1
3
4
2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
× 45°
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
.008 – .010
(0.203 – 0.254)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
SO8 0303
144012fd
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.
15
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
+
50pF
Q3
Q4
100k
2M TYP
100Hz TRIM
= HP5082-2810
= 1N4148
15k
Q7
Q5
= 2N2222
100pF**
10M
f
OUT
= 1% METAL FILM
= POLYSTYRENE
*
0kHz TO 10kHz
**
74C14
Q6
2.7M
0.1µF
–
C2
1/2 LTC1441
1440/1/2 TA04
+
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1443
1.182V Reference with Micropower Quad Comparators
1% Accuracy, 8.5µA Maximum Current, Ref Output Drives 0.01µF
1% Accuracy, 8.5µA Maximum Current, Ref Output Drives 0.01µF
LTC1444/LTC1445 1.2V Reference with Quad Comparator
with Adjustable Hysteresis
LTC1540
1.182V Reference with Nanopower Comparator
with Adjustable Hysteresis
DFN Package 0.3µA Quiescent Current (Typical), Reference
Drives 0.01µF
LTC1541
1.2V Reference with Micropower Amplifier and Comparator DFN Package 1.25% Accuracy, Rail-to-Rail Out, Low Offset Amplifier
LTC1842/LTC1843 1.82V Reference with Dual Comparators
with Adjustable Hysteresis
1% Accuracy, Open-Drain Out, Reference Drives 0.01µF
LTC1998
1.2 Reference with Comparator with Adjustable Thesholds
0.4 Reference with Low Voltage Dual Comparators
Li-Ion Low Battery Monitor, SOT23, 1% Accuracy
LT6700-1
LT6700-2/LT6700-3
SOT23, 1.4V to 18.5V Supply Range, ±2% Over Temperature
144012fd
LT 0806 REV D • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1996
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