LTC1443/LTC1444/LTC1445
Ultralow Power Quad
Comparators with Reference
Features
Description
Ultralow Quiescent Current: 8.5µA Max
n Reference Output Drives 0.01µF Capacitor
n Adjustable Hysteresis (LTC1444/LTC1445)
n Wide Supply Range
Single: 2V to 11V
Dual: ±1V to ±5.5V
n Input Voltage Range Includes the Negative Supply
n TTL/CMOS Compatible Outputs
n Propagation Delay: 12µs (Typ) (10mV Overdrive)
n No Crowbar Current
n 40mA Continuous Source Current
n Pin Compatible Upgrades for MAX924 (LTC1443)
n Low Profile (5mm × 4mm × 0.8mm) DFN Package
The LTC®1443/LTC1444/LTC1445 are ultralow power quad
comparators with a built-in reference. The comparators
feature less than 8.5µA supply current over temperature,
an internal reference (1.182V ±1% for LTC1443 or 1.221V
±1% for LTC1444/LTC1445), programmable hysteresis
(LTC1444/LTC1445) and TTL/CMOS output (LTC1443/
LTC1445) that sinks and sources current (open-drain
output for LTC1444). The reference output can drive a
bypass capacitor of up to 0.01µF without oscillation.
n
Applications
n
n
n
n
Battery-Powered System Monitoring
Threshold Detectors
Window Comparators
Oscillator Circuits
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
The comparators operate from a single 2V to 11V supply
or a dual ± 1V to ±5.5V supply (LTC1443). Comparator
hysteresis is easily programmable using two resistors and
the HYST pin (LTC1444/LTC1445). Each comparator’s
input operates from the negative supply to within 1.3V of
the positive supply. The LTC1443/LTC1445 comparator
output stage can continuously source up to 40mA. By
eliminating the cross-conducting current that normally
happens when the comparator changes logic states, power
supply glitches are eliminated.
The LTC1443/LTC1444/LTC1445 are available in the
16-pin SO, PDIP and DFN packages.
Typical Application
Reference Settling Test Circuit
3
VIN
5V
TO 8V
5 IN A+
–
4 IN A
1.21M
1%
8V
V+
V+
5V
+
2
–
OUT
2mV/DIV
3.4M
1%
Reference Settling
VREF
14 HYST
R1
10k
R2
2.4M
8
R3
430Ω
C1
1.0µF
LTC1445
REF
+
–
1.2V
OUT
2ms/DIV
144345 TA02
V–
9
144345 TA01
144345fe
1
LTC1443/LTC1444/LTC1445
Absolute Maximum Ratings
(Note 1)
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 (LTC1443)................(V + + 0.3V) to (GND – 0.3V)
OUT
(LTC1444/LTC1445).........(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
Commercial..............................................0°C to 70°C
Industrial............................................. – 40°C to 85°C
Storage Temperature Range
PDIP, SO.............................................–65°C to 150°C
DFN.....................................................–65°C to 150°C
Lead Temperature Range (Soldering, 10 sec)
PDIP, SO............................................................300°C
Pin Configuration
TOP VIEW
TOP VIEW
OUT B 1
16 OUT C
OUT B
1
16 OUT C
OUT A 2
15 OUT D
OUT A
2
15 OUT D
V+
3
14 GND/HYST†
13 IN D+
IN A–
4
12
IN D–
+
5
11
IN C+
–
IN B
6
11 IN C+
7
10
IN C–
IN B+
7
10 IN C–
REF 8
9
V–
REF
8
9
V+ 3
IN A– 4
IN A+
IN B–
IN B+
5
6
N PACKAGE
16-LEAD PDIP
14 GND/HYST†
S PACKAGE
16-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 90°C/ W (N)
TJMAX = 150°C, θJA = 150°C/ W (S)
†PIN 14 IS GND FOR THE LTC1443
†PIN 14 IS HYST FOR THE LTC1444 AND LTC1445
IN A
17
13 IN D+
12 IN D–
V–
DHD16 PACKAGE
16-LEAD (5mm × 4mm) PLASTIC DFN
TJMAX = 125°C, θJA = 41.7°C/ W
EXPOSED PAD (PIN 17) INTERNALLY CONNECTED TO V –
†PIN 14 IS GND FOR THE LTC1443
†PIN 14 IS HYST FOR THE LTC1444 AND LTC1445
144345fe
2
LTC1443/LTC1444/LTC1445
Order Information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
SPECIFIED
TEMPERATURE RANGE
LTC1443CN#PBF
LTC1443CN#TRPBF
LTC1443CN
16-Lead PDIP
0°C to 70°C
LTC1443CS#PBF
LTC1443CS#TRPBF
LTC1443CS
16-Lead Plastic SO
0°C to 70°C
LTC1443IN#PBF
LTC1443IN#TRPBF
LTC1443IN
16-Lead PDIP
–40°C to 85°C
LTC1443IS#PBF
LTC1443IS#TRPBF
LTC1443IS
16-Lead Plastic SO
–40°C to 85°C
LTC1444CN#PBF
LTC1444CN#TRPBF
LTC1444CN
16-Lead PDIP
0°C to 70°C
LTC1444CS#PBF
LTC1444CS#TRPBF
LTC1444CS
16-Lead Plastic SO
0°C to 70°C
LTC1444IN#PBF
LTC1444IN#TRPBF
LTC1444IN
16-Lead PDIP
–40°C to 85°C
LTC1444IS#PBF
LTC1444IS#TRPBF
LTC1444IS
16-Lead Plastic SO
–40°C to 85°C
LTC1445CN#PBF
LTC1445CN#TRPBF
LTC1445CN
16-Lead PDIP
0°C to 70°C
LTC1445CS#PBF
LTC1445CS#TRPBF
LTC1445CS
16-Lead Plastic SO
0°C to 70°C
LTC1445IN#PBF
LTC1445IN#TRPBF
LTC1445IN
16-Lead PDIP
–40°C to 85°C
LTC1445IS#PBF
LTC1445IS#TRPBF
LTC1445IS
16-Lead Plastic SO
–40°C to 85°C
LTC1443CDHD#PBF
LTC1443CDHD#TRPBF
1443
16-Lead (5mm × 4mm) Plastic DFN
0°C to 70°C
LTC1443IDHD#PBF
LTC1443IDHD#TRPBF
1443
16-Lead (5mm × 4mm) Plastic DFN
–40°C to 85°C
LTC1444CDHD#PBF
LTC1444CDHD#TRPBF
1444
16-Lead (5mm × 4mm) Plastic DFN
0°C to 70°C
LTC1444IDHD#PBF
LTC1444IDHD#TRPBF
1444
16-Lead (5mm × 4mm) Plastic DFN
–40°C to 85°C
LTC1445CDHD#PBF
LTC1445CDHD#TRPBF
1445
16-Lead (5mm × 4mm) Plastic DFN
0°C to 70°C
LTC1445IDHD#PBF
LTC1445IDHD#TRPBF
1445
16-Lead (5mm × 4mm) Plastic DFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
Electrical
Characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V – = GND = 0V, unless otherwise noted.
SYMBOL
Power Supply
V+
ICC
Comparator
VOS
IIN
VCM
CMRR
PSRR
Noise
VHYST
tPD
PARAMETER
Supply Voltage Range
Supply Current
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
CONDITIONS
MIN
TYP
MAX
UNITS
l
5.5
11.0
8.5
V
µA
l
±3.0
±0.01
±0.02
l
IN + = IN – = 80mV
HYST = REF (LTC1444/LTC1445)
VCM = 2.5V
VIN+ = VIN– = 2.5V
LTC1444/LTC1445
2.0
l
l
l
V–
V – to (V+ – 1.3V)
V+ = 2V to 11V
100Hz to 100kHz
LTC1444, LTC1445
Overdrive = 10mV, COUT = 100pF
Overdrive = 100mV, COUT = 100pF
0.1
0.1
20
l
REF – 50mV
±10.0
±1.0
±1.0
V+ – 1.3V
1.0
1.0
REF
12
4
mV
nA
nA
V
mV/V
mV/V
µVRMS
V
µs
µs
144345fe
3
LTC1443/LTC1444/LTC1445
Electrical
Characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V – = GND = 0V, unless otherwise noted.
SYMBOL
VOH
VOL
PARAMETER
Output High Voltage
Output Low Voltage
CONDITIONS
IO = – 15mA; LTC1443/LTC1445
IO = 1.8mA; LTC1443
IO = 1.8mA; LTC1444/LTC1445
Reference
VREF
Reference Voltage
No Load, LTC1443
No Load, LTC1444/
LTC1445
ISOURCE
ISINK
Reference Output Source Current
Reference Output Sink Current
Noise
Voltage Noise
C Temp Range
I Temp Range
C Temp Range
I Temp Range
∆VREF ≤ 1mV
∆VREF ≤ 2.5mV
∆VREF ≤ 5mV
100Hz to 100kHz
l
MIN
V + – 0.4V
TYP
1.170
1.164
1.209
1.203
100
10
10
1.182
l
l
l
l
l
l
l
l
1.221
MAX
UNITS
V
GND + 0.4V
V
V – + 0.4V
V
1.194
1.200
1.233
1.239
200
15
15
100
V
V
V
V
µA
µA
µA
µVRMS
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
V+ = 3V, V – = GND = 0V, unless otherwise noted.
SYMBOL
Power Supply
V+
ICC
Comparator
VOS
IIN
PARAMETER
CONDITIONS
Supply Voltage Range
Supply Current
IN + = IN – = 80mV, HYST = REF
VCM
CMRR
PSRR
Noise
VHYST
tPD
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
VOH
VOL
Output High Voltage
Output Low Voltage
Reference
VREF
Reference Voltage
MIN
Noise
Reference Output Source Current
Reference Output Sink Current
Noise Voltage
MAX
UNITS
l
5
11.0
8
V
µA
l
±3.0
±0.01
±0.02
±10.0
±1.0
±1.0
+
V – 1.3V
1.0
1.0
1.182
1.194
1.200
1.233
1.239
l
VCM = 1.5V
VIN+ = VIN– = 1.5V
LTC1444/LTC1445
l
l
l
V – to (V+ – 1.3V)
V+ = 2V to 11V
100Hz to 100kHz
LTC1444, LTC1445
Overdrive = 10mV, COUT = 100pF
Overdrive = 100mV, COUT = 100pF
IO = – 10mA; LTC1443/LTC1445
IO = 0.8mA; LTC1443
IO = 0.8mA; LTC1444/LTC1445
No Load, LTC1443
No Load, LTC1444/
LTC1445
ISOURCE
ISINK
TYP
∆VREF ≤ 1mV
∆VREF ≤ 2.5mV
∆VREF ≤ 5mV
100Hz to 100kHz
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
C Temp Range
I Temp Range
C Temp Range
I Temp Range
l
l
l
l
l
l
l
l
l
l
2.0
mV
nA
nA
–
V
V
0.1
mV/V
0.1
mV/V
100
µVRMS
REF – 50mV
REF
V
14
µs
5
µs
V + – 0.4V
V
GND + 0.4V
V
V – + 0.4V
V
1.170
1.164
1.209
1.203
60
10
10
1.221
120
15
15
100
V
V
V
V
µA
µA
µA
µVRMS
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
144345fe
4
LTC1443/LTC1444/LTC1445
Typical Performance Characteristics
LTC1444/LTC1445
Hysteresis Control
Supply Current vs Supply Voltage
5.2
80
60
20
0
–20
–40
4.8
4.6
4.4
4.2
–60
10
0
20
30
VREF – VHYST (mV)
40
4.0
50
1.0
1.186
1.5
2.0
2.5
SUPPLY VOLTAGE (V)
1.212
1.184
1.180
1.178
1.176
1.174
1.170
–60 –40 –20
1.184
0 20 40 60 80 100 120 140
TEMPERATURE (°C)
5
10
15 20 25 30 35
LOAD CURRENT (µA)
40
1.178
45
144345 G07
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
LOAD CURRENT (mA)
144345 G06
Comparator Output Voltage Low
vs Load Current
2.5
TA = 25°C
V+ = 5V
4.0
3.0
V+ = 3V
2.0
V+ = 2V
1.182
0
1.180
OUTPUT VOLTAGE LOW (V)
SINK
SOURCE
144345 G05
OUTPUT VOLTAGE HIGH (V)
REFERENCE OUTPUT VOLTAGE (V)
1.188
1.180
1.181
1.179
5.0
1.190
1.186
1.182
Comparator Output Voltage High
vs Load Current
V+ = 5V
V– = GND
TA = 25°C
V+ = 5V
V– = GND
TA = 25°C
1.183
1.182
LTC1443 Reference Output
Voltage vs Output Load Current
1.192
144345 G03
V+ = 5V
V– = GND
144345 G04
1.194
0 20 40 60 80 100 120
TEMPERATURE (°C)
LTC1443 Reference Output
Voltage vs Output Load Current
1.172
0 20 40 60 80 100 120
TEMPERATURE (°C)
V+ = 3V
V– = 0V
3.8
3.0
–60 –40 –20
3.0
REFERENCE VOLTAGE (V)
REFERENCE VOLTAGE (V)
REFERENCE VOLTAGE (V)
1.184
1.216
V+ = 5V
V– = –5V
4.2
LTC1443 Reference Voltage
vs Temperature
V+ = 5V
1.208
–60 –40 –20
4.6
144345 G02
LTC1444/LTC1445 Reference
Voltage vs Temperature
1.220
V+ = 5V
V– = 0V
5.0
3.4
144345 G01
1.224
IN+ = (IN– + 100mV)
V – = GND (LTC1443)
5.4
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
IN+ – IN– (mV)
TA = 25°C
5.0
40
–80
Supply Current vs Temperature
5.8
1.0
0
10
20
30
40
LOAD CURRENT (mA)
50
60
144345 G08
TA = 25°C
2.0
1.5
V+ = 2V
V+ = 3V
V+ = 5V
1.0
0.5
0
0
10
50 60
20 30 40
LOAD CURRENT (mA)
70
80
144345 G09
144345fe
5
LTC1443/LTC1444/LTC1445
Typical Performance Characteristics
Comparator Response Time
vs Input Overdrive
10mV
50mV
2
20mV
1
0
0
100
–1
0
2
4
6
RESPONSE TIME (µs)
5
8
10
200
TA = 25°C
4
100mV
3
50mV
160
20mV
10mV
2
1
0
140
100
80
60
40
0
20
0
2
OUT CONNECTED TO V+
120
100
–1
TA = 25°C
180
0
4 6 8 10 12 14 16 18
RESPONSE TIME (µs)
144345 G10
0
1
2
3 4 5 6 7 8
SUPPLY VOLTAGE (V)
9
10
144345 G12
144345 G11
Comparator Response Time
vs Load Capacitance
Comparator Short-Circuit Source
Current vs Supply Voltage
12
160
140
10
RESPONSE TIME (µs)
120
SOURCE CURRENT (mA)
Comparator Short-Circuit Sink
Current vs Supply Voltage
SINK CURRENT (mA)
3
100mV
OUTPUT VOLTAGE (V)
4
TA = 25°C
INPUT VOLTAGE (mV)
INPUT VOLTAGE (mV)
OUTPUT VOLTAGE (V)
5
Comparator Response Time
vs Input Overdrive
OUT CONNECTED TO
V– = GND = 0V
100
80
60
40
tPHL
8
tPLH
6
4
20
0
0
1
2
3
SUPPLY VOLTAGE (V)
4
2
5
0
20
60
80
40
LOAD CAPACITANCE (nF)
144345 G14
144345 G13
Supply Current
vs Comparator Input Frequency
Comparator Response Time at
Low Supply Voltage
1000
1000
RESPONSE TIME (µs)
10000
SUPPLY CURRENT (µA)
10000
100
COUT = 55pF
COUT = 15pF
10
1
20mV OVERDRIVE
100
10
100mV OVERDRIVE
COUT = 5pF
1
1
10
100
1k
10k
INPUT FREQUENCY (Hz)
100
100k
1
1.1
1.2
1.3
1.4
1.5
1.6
SUPPLY VOLTAGE (V)
144345 G15
144345 G16
144345fe
6
LTC1443/LTC1444/LTC1445
Pin Functions
LTC1443
16
1
OUT B
OUT D
15
2
OUT A
14
3
V+
13
4
IN A–
IN D+
13
12
5
IN A+
IN D–
12
11
6
IN B –
IN C+
11
IN B+
IN C–
10
OUT B
2
OUT A
3
V+
4
IN A–
IN D+
5
IN A+
IN D–
6
IN B –
IN C+
IN B+
IN C–
GND
–
–
7
8
+
–
+
REF
–
1.2V
+–
LTC1444/LTC1445
OUT C
1
+
–
V–
10
9
7
8
REF
16
15
HYST
–
+
OUT C
OUT D
+
–
+
–
1.2V
+–
14
+
+
V–
9
144345 PF
OUT B (Pin 1): Comparator B Output. (Open-drain output
for LTC1444). Output can source up to 40mA (LTC1443,
LTC1445) and sink 5mA.
IN C – (Pin10): Inverting Input of Comparator C. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
OUT A (Pin 2): Comparator A Output. (Open-drain output
for LTC1444). Output can source up to 40mA (LTC1443,
LTC1445) and sink 5mA.
IN C + (Pin 11): Noninverting Input of Comparator C. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
V + (Pin 3): Positive Supply.
IN D – (Pin 12): Inverting Input of Comparator D. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
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.
IN A + (Pin 5): Noninverting Input of Comparator A. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
IN B – (Pin 6): 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 7): Noninverting Input of Comparator B. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
REF (Pin 8): Reference Output. With respect to V –. Can
source up to 200µA and sink 15µA at 25°C. Drive 0.01µF
bypass capacitor without oscillation.
V – (Pin 9): Negative Supply. Connect to ground for single
supply operation on LTC1443.
IN D + (Pin 13): Noninverting Input of Comparator D. Input
common mode range from V – to V + – 1.3V. Input current
typically 10pA at 25°C.
GND (Pin 14): LTC1443 Ground. Connect to V – for single
supply operation.
HYST (Pin 14): LTC1444/LTC1445 Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF
to VREF – 50mV.
OUT D (Pin 15): Comparator D Output. (Open-drain output
for LTC1444). Output can source up to 40mA (LTC1443,
LTC1445) and sink 5mA.
OUT C (Pin 16): Comparator C Output. (Open-drain output
for LTC1444). Output can source up to 40mA (LTC1443,
LTC1445) and sink 5mA.
Exposed Pad (Pin 17, DFN Package): This pin is internally
connected to V–. Connection is optional, but will improve
thermal dissipation.
144345fe
7
LTC1443/LTC1444/LTC1445
Applications Information
The LTC1443/LTC1444/LTC1445 is a family of quad
micropower comparators with a built-in reference (1.182V
for the LTC1443 and 1.221V for the LTC1444/LTC1445).
Features include programmable hysteresis (LTC1444/
LTC1445), wide supply voltage range (2V to 11V) and the
ability of the reference to drive up to a 0.01µF capacitor without oscillation. The comparator CMOS outputs (LTC1443/
LTC1445) can source up to 40mA while the LTC1444 has
an open-drain output to V –. The supply current glitches
that normally occur when the comparator output switches
states have been eliminated.
Voltage Reference
The internal bandgap reference has a voltage of 1.182V for
LTC1443 or 1.221V for LTC1444/LTC1445 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 15µA with a 5V
supply. The reference can drive a bypass capacitor of up to
0.01µF without oscillation and by inserting a series resistor,
capacitance values up to 100µF can be used (Figure 1).
REFERENCE
OUTPUT
REF
Power Supplies
Comparator Inputs
The comparator inputs can swing from the negative supply (V –) to within 1.3V maximum of the positive supply
(V+). The inputs can be forced 300mV below V – or above
V + without damage, and the typical input leakage current
is only ±10pA.
Comparator Outputs
The LTC1443 comparator output swings between GND
and V + to assure TTL compatibility with a split supply.
The LTC1444 and LTC1445 outputs swing between V –
and V +. The outputs are capable of sourcing up to 40mA
(LTC1443/LTC1445) and sinking up to 5mA while still
maintaining microampere quiescent currents. The output
stage does not generate crowbar switching currents during transitions which helps minimize parasitic feedback
through the supply pins.
C1
LTC144X
+
–
1.2V
V–
144345 F01
Figure 1. Damping the Reference Output
Figure 2 shows the resistor value required for different
capacitor values to achieve critical damping.
1000
RESISTOR VALUE (kΩ)
The comparator family operates from a single 2V to 11V
supply. The LTC1443 includes a separate ground for the
comparator output stage, allowing a split supply ranging
from ± 1V to ±5.5V. Connecting V – to GND on the LTC1443
allows single supply operation. If the comparator output
is required to source more than 1mA or the supply source
impedance is high, V + should be bypassed with a 0.1µF
capacitor.
R1
100
10
1
0.1
0.001
0.01
0.1
1
CAPACITOR VALUE (µF)
10
144345 F02
Figure 2. Damping Resistance vs Bypass Capacitor Value
144345fe
8
LTC1443/LTC1444/LTC1445
Applications Information
Bypassing the reference can help prevent false tripping of
the comparators by preventing glitches on the V + or the
reference output voltage. Figure 3 shows the bypassed
reference output with a square wave applied to the V + pin.
Resistors R1 and R2 set 10mV of hysteresis, while R3
damps the reference response. Note that the comparator
output doesn’t trip.
3
5V
TO 8V
V+
5 IN A+
4 IN A–
+
2
OUT
–
14 HYST
R1
10k
8
R2
2.4M
R3
430Ω
LTC1445
REF
+
–
Hysteresis can be added to the LTC1444/LTC1445 by connecting a resistor (R1) between the REF and HYST pins,
and a second resistor (R2) from HYST to V – (Figure 4).
The difference between the upper and lower threshold voltages or hysteresis voltage band (VHB) is equal to twice the
voltage difference between the REF and HYST pins. When
more hysteresis is added, the upper threshold increases
the same amount as the lower threshold decreases. The
maximum voltage allowed between REF and HYST is
50mV, producing a maximum hysteresis voltage band of
100mV. If hysteresis is not wanted, the HYST pin should
be shorted to REF. Acceptable values for IREF range from
0.1µA to 5µA. If 2.4M is chosen for R2, then R1(kΩ) =
VHB (mV).
1.2V
8
IREF
V–
9
C1
1.0µF
Hysteresis
R1 =
REF
R1
LTC1445
14 HYST
144345 F03a
(
1.221V –
R2 =
R2
Figure 3a. V + Glitching Test Circuit
VHB
(2)(IREF)
9
IREF
VHB
2
)
144345 F04
Figure 4. Programmable Hysteresis
8V
V+
2mV/DIV
5V
VREF
OUT
2ms/DIV
144345 F03b
Figure 3b. V + Glitching Response
144345fe
9
LTC1443/LTC1444/LTC1445
Applications Information
Level Detector
The LTC1444 is ideal for use as a multisupply micropower
level detector as shown in Figure 5.
R1 and R2 form a voltage divider from V1 to the noninverting comparator A input. R6 and R7 are used to
divide down V2, while R8 is the output pull-up resistor
for the comparator outputs. R3 and R4 set the hysteresis
voltage and R5 and C1 bypass the reference output.
5V
3
V2
V+
R6
1.82M
1%
7 IN B+
–
6 IN B
V1
R2
3.40M
1%
+
OUT B 1
–
1/2LTC1444
5 IN A+
R7
1.21M
1%
–
4 IN A
R1
1.21M
1%
R8
2M
1%
+
OUT A 2
–
14 HYST
R3
15k, 1%
R4
2.4M
1%
8
R5
430Ω
5%
C1
1.0µF
REF
+
–
1.2V
V–
9
144345 F05
Figure 5. Glitch-Free Level Detector with Hysteresis
The following design procedure can be used to select the
component values:
1. Choose the V1 voltage trip level, in this example 4.65V.
2. Calculate the required resistive divider ratio.
Ratio = VREF/ VIN
Ratio = 1.221V/4.65V = 0.263
3. Choose the required hysteresis voltage band at the input,
VHBIN, in this example 60mV. Calculate the hysteresis
voltage band referred to the comparator input VHB.
VHB = (VHBIN)(Ratio)
VHB = (60mV)(0.263)
VHB = 15.78mV
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.
R1 = VREF/IBIAS = 1.221V/1µA ≈ 1.21M
VIN
R2 = (R1)
− 1
VREF + VHB
2
4.65V
R2 = (1.21M)
− 1
1.221V + 15mV
2
R2 = 3.40M
Using the same equations, R6 and R7 are 1.82M and
1.21M, respectively, to set the trip level at 3V for V2.
144345fe
10
LTC1443/LTC1444/LTC1445
Package Description
N Package
16-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.770*
(19.558)
MAX
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
.255 ±.015*
(6.477 ±0.381)
.300 – .325
(7.620 – 8.255)
.130 ±.005
(3.302 ±0.127)
.020
(0.508)
MIN
.008 – .015
(0.203 – 0.381)
(
+.035
.325 –.015
+0.889
8.255
–0.381
NOTE:
1. DIMENSIONS ARE
.045 – .065
(1.143 – 1.651)
.065
(1.651)
TYP
.120
(3.048)
MIN
)
.018 ±.003
(0.457 ±0.076)
.100
(2.54)
BSC
N16 REV I 0711
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S Package
16-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
.386 – .394
(9.804 – 10.008)
NOTE 3
.045 ±.005
.050 BSC
16
N
14
13
12
11
10
9
N
.245
MIN
.160 ±.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
1
.030 ±.005
TYP
15
2
3
N/2
N/2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
× 45°
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
1
2
3
4
5
.053 – .069
(1.346 – 1.752)
NOTE:
1. DIMENSIONS IN
.014 – .019
(0.355 – 0.483)
TYP
7
8
.004 – .010
(0.101 – 0.254)
0° – 8° TYP
.016 – .050
(0.406 – 1.270)
6
.050
(1.270)
BSC
S16 REV G 0212
INCHES
(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)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
144345fe
11
LTC1443/LTC1444/LTC1445
Package Description
DHD Package
16-Lead Plastic DFN (5mm × 4mm)
(Reference LTC DWG # 05-08-1707 Rev Ø)
0.70 ±0.05
4.50 ±0.05
3.10 ±0.05
2.44 ±0.05
(2 SIDES)
PACKAGE
OUTLINE
0.25 ±0.05
0.50 BSC
4.34 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
5.00 ±0.10
(2 SIDES)
R = 0.20
TYP
4.00 ±0.10
(2 SIDES)
9
R = 0.115
TYP
0.40 ±0.10
16
2.44 ±0.10
(2 SIDES)
PIN 1
TOP MARK
(SEE NOTE 6)
PIN 1
NOTCH
8
0.200 REF
1
0.25 ±0.05
0.50 BSC
0.75 ±0.05
0.00 – 0.05
(DHD16) DFN 0504
4.34 ±0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJGD-2) IN JEDEC
PACKAGE OUTLINE MO-229
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 THE
TOP AND BOTTOM OF PACKAGE
144345fe
12
LTC1443/LTC1444/LTC1445
Revision History
(Revision history begins at Rev D)
REV
DATE
DESCRIPTION
PAGE NUMBER
D
4/11
Minor update to Figure 5 in the Applications Information section
E
5/12
Internal Voltage Reference Symbol Updated
10
1, 7, 8, 9, 10, 14
DFN Package Description Corrected
2
DFN Storage Temperature Range Increased to 150°C
2
Order Information Corrected
3
Related Parts Updated
14
144345fe
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
13
LTC1443/LTC1444/LTC1445
Typical Application
Single Cell to 5V Supply
R1
1.1M
5%
5
R2
82.5k
1%
1 CELL
LITHIUMION
BATTERY
4
6
+
V+
A
1/4 LTC1444
–
R7
51k
5%
–
+
6
7
VIN
SW
C2
100µF
3
1
14
NC
NC
R5
51k
5%
R4
2.4M
5%
D1
1N5817
2
B
1/4 LTC1444
7 + HYST
R3
1M
1%
L1
10µH
SUMIDA
CD54-100
3
5
2
SENSE
4
1
SHDN
3
LT1300
ILIM
+
SEL
PWR GND
8
GND
C3
100µF
1
8
REF
R6
430Ω
5%
+
–
C1
1µF
1.2V
2, 4
Q1
MMFT2955ETI
R9
267k
1%
R8
732k
1% 11
10
+
C
1/4 LTC1444
–
LTC1444
REF
16
R10
3.37M
5%
R11
51k
5%
13
R12
51k
15 5%
12
+
D
1/4 LTC1444
VCC
NMI
µP
RESET
–
C4
0.22µF
V–
9
144345 TA03
C2, C3: AUX TPSD107M010R0100 OR
SANYO OS-CON 16SA100M
Related Parts
PART NUMBER
DESCRIPTION
COMMENTS
LTC1041
Bang-Bang Controller with 1nA Off Current
2.8V to 18V, Ideal for Temperature or Motor Control Circuit
LTC1042
Micropower, High Accuracy Window Comparator
Fault Detect, Go/No Go Test, Supply Monitor
LTC1440/LTC1540
Ultralow Power Comparator with Reference
1.128V ±1% Reference, ±10mV (Max) Input Offset
LTC1441/LTC1442
Dual Ultralow Power Comparators with Reference
1.182V ±1% Reference, 8µs Prop Delay, 5.7µA
LTC1541/LTC1542
Combined Amplifier, Comparator and Reference
1.2V ±0.8 Reference, Amplifier Stable with 1000pF Load
LTC1842/LTC1843
Dual Ultralow Power Comparators with Reference
1.182V ±1% Reference, 4µs, 3.5µA, Open-Drain Out
LTC1921
Dual Independent Monitors for –48V Supply and Fuse
–48V Telecom and Network Backplane Monitor
LTC1998
High Accuracy Comparator with 1.2V Reference
Adjustable Threshold and Hysteresis, 2.5mA Supply
LT®6700
Dual Comparators with 400mV Reference
1.4V to 18V Operation, 18µs Prop Delay,
Available in SOT-23 and 2mm × 3mm DFN Packages
LT6703
Single Comparator with 400mV Reference
1.4V to 18V Operation, 6.5µA Supply Current,
Available in SOT-23 and 2mm × 2mm DFN Packages
144345fe
14 Linear Technology Corporation
LT 0512 REV E • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 1995
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