LTC8701, LTC8702, LTC8703, LTC8704
P-1
General Description
The LTC8701/8702/8703/8704 devices are single-, dual-, and quad- channel comparators
with push-pull output that are ideal for power-sensitive, low-voltage
applications. Featuring a nano-power (typical 310 nA), fast 12 μs propagation delay, and a
wide range of supply voltages from 1.7 V to 5.5 V with rail-to-rail common-mode voltage
range makes the LTC8701/8702/8703/8704 an ideal choice for a wide variety of portable
electronics applications, such as handsets, tablets, notebooks and portable devices that
have extremely power constraints and tight board space.
The output of the LTC8701/8702/8703/8704 pulls to within 0.1 V of either supply rail
without external pull-up circuitry, making these devices ideal for interface with both
CMOS and TTL logics. All input and output pins can tolerate a continuous short-circuit
fault condition to either rail. Internal hysteresis ensures clean output switching, even with
slow-moving input signals.
The LTC8701/LTC8703 (single) is available in both SOT23-5L and SC70-5L packages. The
LTC8702 (dual) is offered in SOIC-8L, MSOP-8L and DFN-8L packages. The quad-channel
LTC8704 is offered in both SOIC-14L and TSSOP-14L packages. All devices are rated over
−40 ℃ to +85 ℃ industrial temperature range.
Features and Benefits
Nanopower Operating Current (310 nA) Preserves Battery Power
Propagation Delay: 12 μs (100-mV Overdrive)
Rail-to-Rail Input
Push-Pull Output Current Drive: 30 mA Typically at 5V Supply
Internal Hysteresis for Clean Switching
Internal RF/EMI Filter
Single 1.7 V to 5.5 V Supply Voltage Range
– Can be Powered From the Same 1.8V/2.5V/3.3V/5V System Rails
Operating Temperature Range: −40 ℃ to +85 ℃
Applications
Handsets, Tablets and Notebooks
Wearables and Consumer Accessories
Portable Medical Instruments
Alarms and Monitoring Circuits
Level Detectors
IR Receivers
Multi-vibrators
Pin Configurations (Top View)
LTC8701
LTC8701R
LTC8702
LTC8704
SOT23-5L / SC70-5L
SOT23-5L
SOIC-8L / MSOP-8L
SOIC-14L / TSSOP-14L
OUT 1
5 +VS
–VS 2
5 –VS
OUT 1
+VS 2
4 –IN
+IN 3
4 –IN
+IN 3
LTC8701
LTC8702
DFN-8L
DFN-8L
OUT 1
8 +VS
OUTA
1
OUTA
1
–INA
2
+INA
3
–VS
4
A
B
8
+VS
7
OUTB
6
–INB
5
+INB
LTC8703
SOT23-5L / SC70-5L
OUTA
1
–INA
2
A
14
OUTD
13
–IND
D
+INA
3
12
+IND
+VS
4
11
–VS
+INB
5
10
+INC
B
C
–INB
6
9
–INC
OUTB
7
8
OUTC
8 +VS
–IN 2
7 NC
–INA
2
7 OUTB
+IN 3
6 –VS
+INA
3
6 –INB
NC 4
5 NC
–VS
4
5 +INB
+IN 1
5 +VS
–VS 2
–IN 3
4 OUT
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-2
Pin Description
Symbol
Description
–IN
Negative input. The voltage range is from (VS– – 0.1V) to (VS+ + 0.1V).
+IN
Positive input. This pin has the same voltage range as –IN.
+VS
Positive power supply. The voltage is from 1.7V to 5.5V. Split supplies are possible
as long as the voltage between VS+ and VS– is from 1.7V to 5.5V.
–VS
Negative power supply. It is normally tied to ground. It can also be tied to a voltage
other than ground as long as the voltage between VS+ and VS– is from 1.7V to 5.5V.
OUT
Comparator output.
Ordering Information
Orderable
Type Number
Package
Name
Package Quantity
Eco Class(1)
Operating
Temperature
Marking
Code
LTC8701YT5/R6
SOT23-5L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL1
LTC8701YC5/R6
SC70-5L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL1
LTC8701YF8/R6
DFN2x2-8L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL1
LTC8701RYT5/R6
SOT23-5L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL9
LTC8702YS8/R8
SOIC-8L
Tape and Reel, 4 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL2 Y
LTC8702YV8/R6
MSOP-8L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL2Y
LTC8702YF8/R6
DFN2x2-8L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL2
LTC8703YT5/R6
SOT23-5L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL3
LTC8703YC5/R6
SC70-5L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL3
LTC8704YS14/R5
SOIC-14L
Tape and Reel, 2 500 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL4 Y
LTC8704YT14/R6
TSSOP-14L
Tape and Reel, 3 000 Green (RoHS & no Sb/Br) –40℃ to +85℃
CL4 Y
(1) Eco Class - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & Halogen Free).
(2) Please contact to your Linearin representative for the latest availability information and product content
details.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-3
Limiting Value
In accordance with the Absolute Maximum Rating System (IEC 60134).
Parameter
Absolute Maximum Rating
Supply Voltage, VS+ to VS–
10.0 V
Signal Input Terminals: Voltage, Current
VS– – 0.3 V to VS+ + 0.3 V, ±10 mA
Output Short-Circuit
Continuous
Storage Temperature Range, Tstg
–65 ℃ to +150 ℃
Junction Temperature, TJ
150 ℃
Lead Temperature Range (Soldering 10 sec)
260 ℃
ESD Rating
Parameter
Electrostatic
Discharge Voltage
Item
Value
Human body model (HBM), per MIL-STD-883J / Method 3015.9
±5 000
Charged device model (CDM), per ESDA/JEDEC JS-002-2014
±2 000
Machine model (MM), per JESD22-A115C
±250
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
Unit
V
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-4
Electrical Characteristics
VS = 5.0V, TA = +25℃, unless otherwise noted.
Boldface limits apply over the specified temperature range, TA = −40 to +85 ℃.
Symbol
Parameter
Conditions
Min.
Typ.
Max.
±0.5
±3.5
Unit
OFFSET VOLTAGE
VCM = 0
VOS
Input offset voltage
VOS TC
Offset voltage drift
TA = −40 to +85 ℃
PSRR
Power supply
rejection ratio
VS = 1.7 to 5.5 V, VCM < (VS+ − 1V)
65
TA = −40 to +85 ℃
60
VHYST
Input hysteresis
VCM = 0
5
VCM = VS /2
5
TA = +85 ℃
150
VCM = VS /2
10
TA = −40 to +85 ℃
±4.0
mV
μV/℃
±1
85
dB
mV
INPUT BIAS CURRENT
IB
Input bias current
IOS
Input offset current
pA
pA
INPUT VOLTAGE RANGE
VCM
CMRR
Common-mode
voltage range
Common-mode
rejection ratio
VS––0.1
VCM = −0.1 to 5.1 V
62
VCM = 0 to 4.8 V, TA = −40 to +85 ℃
56
VS = 1.8 V, VCM = −0.1 to 1.9 V
60
VCM = 0 to 1.6 V, TA = −40 to +85 ℃
55
VS++0.1
V
84
dB
82
INPUT IMPEDANCE
RIN
Input resistance
CIN
Input capacitance
100
GΩ
Differential
2.0
Common mode
3.5
pF
OUTPUT
VOH
High output voltage
swing
ISOURCE = 1 mA
VS+–90
TA = −40 to +85 ℃
VS+–120
VOL
Low output voltage
swing
ISINK = 1 mA
ISC
Output short-circuit
current
Source current, OUT to VS /2
VS+–73
VS–+48
TA = −40 to +85 ℃
mV
VS–+60
VS–+80
30
Sink current, OUT to VS /2
36
–27
–22
mV
mA
POWER SUPPLY
VS
IQ
Operating supply
voltage
Quiescent current
(per comparator)
TA = −40 to +85 ℃
1.7
5.5
VS = 1.8 V, VCM = 0.3V
310
VS = 1.8 V, VCM = 1.5V
380
VS = 5.0 V, VCM = 0.3V
355
VS = 5.0 V, VCM = 4.7V
440
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
V
nA
670
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-5
Electrical Characteristics (continued)
VS = 5.0V, TA = +25℃, unless otherwise noted.
Boldface limits apply over the specified temperature range, TA = −40 to +85 ℃.
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Unit
SWITCHING CHARACTERISTICS
tPD+
Propagation delay
time, Low to high
tPD–
Propagation delay
time, High to low
tR
Rise time
tF
Fall time
THERMAL CHARACTERISTICS
TA
θJA
Input overdrive = 10 mV,
CL = 15 pF
Input overdrive = 100 mV,
CL = 15 pF
Input overdrive = 10 mV,
CL = 15 pF
Input overdrive = 100 mV,
CL = 15 pF
Input overdrive = 10 mV,
CL = 15 pF
Input overdrive = 100 mV,
CL = 15 pF
Input overdrive = 10 mV,
CL = 15 pF
Input overdrive = 100 mV,
CL = 15 pF
Operating
temperature range
Package Thermal
Resistance
16
17
μs
13
230
ns
190
300
ns
220
-40
+85
SC70-5L
333
SOT23-5L
190
DFN2x2-8L
80
MSOP-8L
216
SOIC-8L
125
TSSOP-14
112
SOIC-14L
115
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
μs
12
℃
℃/W
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-6
Typical Performance Characteristics
At TA=+25℃, VS=5.0V, VCM=VS /2, RL=10kΩ, and CL=15pF, unless otherwise noted.
600
VCM=0.8V
= 0.5V
500
+85℃
Supply Current (nA)
Supply Current (nA)
600
+25℃
400
300
–40℃
200
100
VCM = 3.0V
TA = +85℃
500
400
300
200
100
0
0
0
1
2
3
4
5
6
0
1
Supply Voltage (V)
Supply Current vs. Supply Voltage
400
Supply Current (nA)
Supply Current (nA)
4
5
6
5
6
600
+125℃
VVSS=1.8V
=1.8V
+85℃
300
+25℃
–40℃
200
100
VVSS==1.8V
5V
500
+85℃
+25℃
400
300
–40℃
200
100
0
0
0
0.5
1
1.5
0
2
Common-Mode Voltage (V)
Supply Current vs. Common-Mode Input (VS = 1.8V)
350
100
3
4
VCM = –VS
300
Distribution (Unit)
150
2
Supply Current vs. Common-Mode Input (VS = 5.0V)
VCM = –VS
200
1
Common-Mode Voltage (V)
250
250
200
150
100
50
50
0
0
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
Distribution (Unit)
3
Supply Current vs. Supply Voltage
500
300
2
Supply Voltage (V)
Offset Voltage (mV)
Offset Voltage Production Distribution
Input Hysteresis (mV)
Hysteresis Production Distribution
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-7
Typical Performance Characteristics
At TA=+25℃, VS=5.0V, VCM=VS /2, RL=10kΩ, and CL=15pF, unless otherwise noted.
8
5
Sourcing Current
Hysteresis+
4
Output Voltage (V)
VOS and VHYST (mV)
6
Offset
2
0
-2
Hysteresis–
-4
4
–40℃
3
+85℃
+25℃
2
1
-6
Sinking Current
0
-8
0
1
2
3
4
0
5
10
Common-Mode Voltage (V)
40
Output Voltage vs. Output Current
-20
Short-Circuit Current (mA)
-2.5
Short-Circuit Current (mA)
30
Output Current (mA)
VOS and VHYST vs. Common-Mode Input
VS = 1.8V
-2.7
-2.9
-3.1
-3.3
VS = 5.0V
-25
-30
-35
-3.5
-40
-40
0
40
80
120
-40
0
Temperature (℃)
40
80
120
Temperature (℃)
Short-Circuit Current vs. Temperature (VS = 1.8V)
Short-Circuit Current vs. Temperature (VS = 5.0V)
20
16
VCM = VS / 2
VOD = 20mV
18
16
Propagation Delay L-H (μs)
Propagation Delay H-L (μs)
20
+85℃
14
12
10
8
+25℃
6
–40℃
4
2
0
VCM = VS / 2
VOD = 20mV
14
+85℃
12
10
8
–40℃
6
+25℃
4
2
0
0
1
2
3
4
5
6
0
Supply Voltage (V)
Propagation Delay H-L (tPD–) vs. Supply Voltage
1
2
3
4
5
Supply Voltage (V)
Propagation Delay L-H (tPD+) vs. Supply Voltage
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
6
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-8
Typical Performance Characteristics
At TA=+25℃, VS=5.0V, VCM=VS /2, RL=10kΩ, and CL=15pF, unless otherwise noted.
25
VS = 1.8V
VCM = VS/2
20
Propagation Delay (μs)
Propagation Delay (μs)
25
15
tPD– (H-L)
10
tPD+ (L-H)
5
VS = 5.0V
VCM = VS/2
20
15
10
tPD+ (L-H)
5
0
tPD– (H-L)
0
1
10
100
1000
1
10
Overdrive Voltage (mV)
Propagation Delay vs. Input Overdrive (VS = 1.8V)
70
Propagation Delay H-L (μs)
Propagation Delay L- (μs)
1000
Propagation Delay vs. Input Overdrive (VS = 5.0V)
80
70
60
50
+85℃
40
+25℃
30
20
10
–40℃
60
50
+85℃
40
+25℃
30
20
10
0
–40℃
0
10
100
1000
10
100
Overdrive Voltage (mV)
1000
Overdrive Voltage (mV)
Propagation Delay H-L (tPD–) vs. Input Overdrive
Propagation Delay L-H (tPD+) vs. Input Overdrive
10
10
VOD = 100mV
Propagation Delay (μs)
Propagation Delay (μs)
100
Overdrive Voltage (mV)
8
6
4
2
0
VOD = 100mV
8
6
4
2
0
0
1
2
3
4
5
6
0
Common-Mode Voltage (V)
Propagation Delay H-L (tPD–) vs. Input CommonMode Voltage
1
2
3
4
5
6
Common-Mode Voltage (V)
Propagation Delay L-H (tPD+) vs. Input CommonMode Voltage
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-9
Typical Performance Characteristics
At TA=+25℃, VS=5.0V, VCM=VS /2, RL=10kΩ, and CL=15pF, unless otherwise noted.
100
120
VS = 1.8V
VOD = 100mV
Propagation Delay (μs)
Propagation Delay (μs)
120
80
60
tPD+ (L-H)
40
tPD– (H-L)
20
0
0.01
0.1
1
10
100
80
20
10
100
50
VS = 5.0V
VOD = 100mV
45
Propagation Delay (μs)
Propagation Delay (μs)
1
Propagation Delay vs. Capacitive Load (VS = 1.8V)
45
30
25
20
tPD+ (L-H)
15
tPD– (H-L)
10
5
0
0.01
0.1
Output Capacitive Load (nF)
Propagation Delay vs. Capacitive Load (VS = 1.8V)
35
tPD– (H-L)
40
Output Capacitive Load (nF)
40
tPD+ (L-H)
60
0
0.01
100
VS = 1.8V
VOD = 20mV
0.1
1
10
100
40
35
30
25
tPD+ (LH)
tPD– (H-L)
20
15
10
5
0
0.01
Output Capacitive Load (nF)
Propagation Delay vs. Capacitive Load (VS = 5.0V)
VS = 5.0V
VOD = 20mV
0.1
1
10
100
Output Capacitive Load (nF)
Propagation Delay vs. Capacitive Load (VS = 5.0V)
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-10
Application Notes
OPERATING VOLTAGE
The LTC8701/8702/8703/8704 family of nano-power
comparators is fully specified and ensured for
operation from 1.7V to 5.5V (±0.85V to ±2.75V). In
addition, and many specifications apply over the
industrial temperature range of –40℃ to +85℃.
Parameters that vary significantly with operating
voltages or temperature are illustrated in the Typical
Characteristics graphs.
NOTE: Supply voltages (VS+ to VS–) higher than +10V
can permanently damage the device.
INPUT VOLTAGE
The input common-mode voltage range of the
LTC8701/8702/8703/8704 comparators extends 100mV beyond the supply rails. This performance is
achieved with a complementary input stage: an Nchannel input differential pair in parallel with a Pchannel differential pair. The N-channel pair is active
for input voltages close to the positive rail, typically
VS+–1.4V to the positive supply, whereas the Pchannel pair is active for inputs from 100mV below
the negative supply to approximately VS+–1.4V. There
is a small transition region, typically VS+–1.2V to VS+–
1V, in which both pairs are on. This 200mV transition
region can vary up to 200mV with process variation.
Thus, the transition region (both stages on) can range
from VS+–1.4V to VS+–1.2V on the low end, up to VS+–1V
to VS+–0.8V on the high end. Within this transition
region, PSRR, CMRR, offset voltage, offset drift, and
THD can be degraded compared to device operation
outside this region.
INPUT VOLTAGE
The LTC8701/8702/8703/8704 comparator family
uses CMOS transistors at the inputs which prevent
phase inversion when the input pins exceed the
supply voltages.
VS+
D1
RS1
500Ω
IN+
D2
D3
CCM1
RS2 CDM
500Ω
IN–
D4
CCM2
VS–
Figure 1. Input EMI Filter and Clamp Circuit
Figure 1 shows the input EMI filter and clamp circuit.
The LTC8701/8702/8703/8704 comparators have
internal ESD protection diodes (D1, D2, D3, and D4)
that are connected between the inputs and each
supply rail. These diodes protect the input transistors
in the event of electrostatic discharge and are
reverse biased during normal operation. This
protection scheme allows voltages as high as
approximately 300mV beyond the rails to be applied
at the input of either terminal without causing
permanent damage. See the table of Absolute
Maximum Ratings for more information.
EMI REJECTION RATIO
Circuit performance is often adversely affected by
high frequency EMI. When the signal strength is low
and transmission lines are long, an amplifier must
accurately amplify the input signals. However, all
comparator pins — the non-inverting input, inverting
input, positive supply, negative supply, and output
pins — are susceptible to EMI signals. These high
frequency signals are coupled into an comparator by
various means, such as conduction, near field
radiation, or far field radiation. For example, wires
and printed circuit board (PCB) traces can act as
antennas and pick up high frequency EMI signals.
Amplifiers do not amplify EMI or RF signals due to
their relatively low bandwidth. However, due to the
nonlinearities of the input devices, comparators can
rectify these out of band signals. When these high
frequency signals are rectified, they appear as a dc
offset at the output.
The LTC8701/8702/8703/8704 comparators have
integrated EMI filters at their input stage. A
mathematical method of measuring EMIRR is defined
as follows:
EMIRR = 20 log (VIN_PEAK / ΔVOS)
INTERNAL HYSTERESIS
Most high-speed comparators oscillate in the linear
region because of noise or undesired parasitic
feedback. This tends to occur when the voltage on
one input is at or equal to the voltage on the other
input. To counter the parasitic effects and noise, the
devices have an internal hysteresis of 5 mV.
The hysteresis in a comparator creates two trip
points: one for the rising input voltage and one for
the falling input voltage. The difference between the
trip points is the hysteresis. The average of the trip
points is the offset voltage. When the comparator’s
input voltages are equal, the hysteresis effectively
causes one comparator input voltage to move quickly
past the other, thus taking the input out of the region
where oscillation occurs. Standard comparators
require hysteresis to be added with external
resistors. To increase hysteresis and noise margin
even more, add positive feedback with two resistors
as a voltage divider from the output to the noninverting input. Figure 2 illustrates the case where
I N –
i s
f i x e d
a n d
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-11
Application Notes
IN+ is varied. If the inputs were reversed, the figure
would look the same, except the output would be
inverted.
VTRIP+
VIN+
VHYST
VOS
VIN– = 0
VTRIP–
VOS = (VTRIP+ + VTRIP–)/2
VOH
Comparator
Output
VOL
Figure 2. Input and Output Waveform, Non-inverting
Input Varied
MAXIMIZING PERFORMANCE THROUGH PROPER
LAYOUT
to the temperature of the junction. The most common
metallic junctions on a circuit board are solder-toboard trace and solder-to-component lead. If the
temperature of the PCB at one end of the component
is different from the temperature at the other end,
the resulting Seebeck voltages are not equal,
resulting in a thermal voltage error.
This thermocouple error can be reduced by using
dummy components to match the thermoelectric
error source. Placing the dummy component as
close as possible to its partner ensures both
Seebeck voltages are equal, thus canceling the
thermocouple error. Maintaining a constant ambient
temperature on the circuit board further reduces this
error. The use of a ground plane helps distribute heat
throughout the board and reduces EMI noise pickup.
INPUT-TO-OUTPUT COUPLING
To minimize capacitive coupling, the input and output
signal traces should not be parallel. This helps
reduce unwanted positive feedback.
To achieve the maximum performance of the
extremely high input impedance and low offset
voltage of the LTC8701/8702/8703/8704 devices, care
is needed in laying out the circuit board. The PCB
surface must remain clean and free of moisture to
avoid leakage currents between adjacent traces.
Surface coating of the circuit board reduces surface
moisture and provides a humidity barrier, reducing
parasitic resistance on the board. The use of guard
rings around the comparator inputs further reduces
leakage currents. Figure 3 shows proper guard ring
configuration and the top view of a surface-mount
layout. The guard ring does not need to be a specific
width, but it should form a continuous loop around
both inputs. By setting the guard ring voltage equal to
the voltage at the non-inverting input, parasitic
capacitance is minimized as well. For further
reduction of leakage currents, components can be
mounted to the PCB using Teflon standoff insulators.
Guard
Ring
+IN
–IN
+VS
Figure 3. Use a guard ring around sensitive pins
Other potential sources of offset error are
thermoelectric voltages on the circuit board. This
voltage, also called Seebeck voltage, occurs at the
junction of two dissimilar metals and is proportional
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-12
Typical Application Circuits
IR RECEIVER AFE AND WAKE- UP CIRCUIT
Infrared (IR) communication is inherently immune to
RF interference as long as there is a line-of-sight
path between the transmitter and the receiver. It is
also one of the lowest cost communication schemes.
This makes it a good choice for implementing
wireless communications in applications such as
utility metering. These smart utility meters are
hermetically sealed and use a combination of
batteries and solar cells to power the system.
Maintenance in the field can be costly, so minimizing
system power consumption to extend battery life is
desired.
A common system topology to extend battery life is
to use a power efficient IR receiver analog front end
(AFE) that is always on and wakes up the host only
when there is a valid IR signal detected as shown in
Figure 1. Power efficient comparators such as the
LTC870x can be used in the IR receiver AFE to
increase battery life.
IR
LED
IR Receiver
AFE
Digital output
(hardware wake-up
event)
GPIO
MCU
(Low
Power)
+ CR2032
10MΩ
Figure 4. Coin Cell Battery Powered IR Receiver
The LTC870x device is responsible for two major
tasks:
1. IR signal conditioning,
2. Host system wake-up.
The benefits of LTC870x for this application include
the following:
1. Nano quiescent supply current (310 nA),
2. Low input bias current (5 pA) which allows a
greater load resistor value.
The LTC870x device is constantly powered to always
be ready to receive IR signals and wake up the host
microcontroller (MCU) when data is received. The
short working distance (approx 5 cm) is suitable for
a virtual-contact operation where the IR transmitter
and receiver are closely placed with an optional
mechanical alignment guide.
Figure 1 shows the IR receiver system block diagram.
The host MCU is normally in the shutdown mode
(during which the quiescent current is less than 1 μA)
except when data is being transferred.
Figure 2 shows the detailed circuit design. The circuit
establishes a threshold through R2 and C1 which
automatically adapts to the ambient light level. To
further reduce BOM cost, this example uses an IR
LED as the IR receiver. The IR LED is reverse-biased
to function as a photodiode (but at a reduced
sensitivity).
VREF
3V
R2
R3
R4
470kΩ
470kΩ
10MΩ
3V
IR
LED
LTC8701
Output to MCU
(Also to wake-up MCU)
R1
10MΩ
C1
0.01μF
Figure 5. IR Receiver AFE Using LTC8701 (Push- Pull
Output)
The low input bias current allows a greater load
resistor value (R1) without sacrificing linearity, which
in turn helps reduce the always-on supply current.
The load resistor R1 converts the IR light induced
current into a voltage fed into the inverting input of
the comparator. R2 and C1 establish a reference
voltage VREF which tracks the mean amplitude of the
IR signal. The non-inverting input is connected to VREF
through R3. And finally R3 and R4 are used to
introduce additional hysteresis to keep the output
free of spurious toggles.
To achieve years of operation running on a single
coin cell battery, the host MCU must be put in the
shutdown power state. The MCU wakes up when data
is received. After the data transmission is complete,
the MCU reverts to the shutdown state and the
overall supply current drops back to the micro amps
level.
PARAMETER
Aggregated alwayson Current
2 μA
Peak Current
(Wireless Radio + IR
LED)
30 mA
Active Duration
/Frequency
30 sec/30 days
CR 2032 Coin Cell
Battery Capacity
240 mAh
CR 2032 Lifespan
(minimum)
5 years
Lead Temperature
Range (Soldering 10
sec)
260 ℃
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
P-13
LTC8701, LTC8702, LTC8703, LTC8704
Typical Application Circuits
Table 1 shows a power budget based on the following
assumptions:
1. The aggregated always-on quiescent current
is estimated as 2 μA, which includes the
LTC8701 quiescent current, divider network
current, and the MCU and supporting devices
current in the shutdown state.
2. Peak current during active data transmission
and RF radio operation is estimated as 30 mA.
3. Each active session last for 30 seconds or
less for every 30 days or longer.
4. The coin cell is based on an Energizer CR2032,
which is specified at 240 mAh and includes a
1% annual self-discharge rate.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-14
Tape and Reel Information
REEL DIMENSIONS
TAPE DIMENSIONS
K0
P1
B0 W
Reel
Diameter
A0
Cavity
A0
B0
K0
W
P1
Reel
Width (W1)
Dimension designed to accommodate the component width
Dimension designed to accommodate the component length
Dimension designed to accommodate the component thickness
Overall width of the carrier tape
Pitch between successive cavity centers
QUADRANT ASSIGNMENTS FOR PIN 1 ORIETATION IN TAPE
Sprocket Holes
Q1
Q2
Q1
Q2
Q3
Q4
Q3
Q4
User Direction of Feed
Pocket Quadrants
* All dimensions are nominal
Device
LTC8701YT5/R6
Package
Pins
Type
SOT23
5
SPQ
3 000
Reel
Reel
Diameter Width W1
(mm)
(mm)
178
9.0
A0
(mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
(mm)
Pin 1
Quadrant
3.3
3.2
1.5
4.0
8.0
Q3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-15
Package Outlines
DIMENSIONS, SOT23-5L
A2
A
A1
D
e1
Symbol
A
A1
A2
b
c
D
E1
E
e
e1
L
L1
θ
θ
L
E
E1
L1
e
b
Dimensions
In Millimeters
Min
Max
1.25
0.04
0.10
1.00
1.20
0.33
0.41
0.15
0.19
2.820
3.02
1.50
1.70
2.60
3.00
0.95 BSC
1.90 BSC
0.60 REF
0.30
0.60
0°
8°
Dimensions
In Inches
Min
Max
0.049
0.002
0.004
0.039
0.047
0.013
0.016
0.006
0.007
0.111
0.119
0.059
0.067
0.102
0.118
0.037 BSC
0.075 BSC
0.024 REF
0.012
0.024
0°
8°
c
RECOMMENDED SOLDERING FOOTPRINT, SOT23-5L
1.0
0.039
0.95
0.037
0.95
0.037
0.7
0.028
2.4
0.094
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
mm
( inches
)
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-16
Package Outlines (continued)
DIMENSIONS, SC70-5L (SOT353)
A2
A
Symbol
A1
D
e1
A
A1
A2
b
C
D
E
E1
e
e1
L
L1
θ
θ
e
L
E1
E
L1
b
Dimensions
In Millimeters
Min
Max
0.90
1.10
0.00
0.10
0.90
1.00
0.15
0.35
0.08
0.15
2.00
2.20
1.15
1.35
2.15
2.45
0.65 typ.
1.20
1.40
0.525 ref.
0.26
0.46
0°
8°
C
RECOMMENDED SOLDERING FOOTPRINT, SC70-5L (SOT353)
0.50
0.0197
0.65
0.025
0.65
0.025
0.40
0.0157
1.9
0.0748
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
mm
( inches
)
Dimensions
In Inches
Min
Max
0.035
0.043
0.000
0.004
0.035
0.039
0.006
0.014
0.003
0.006
0.079
0.087
0.045
0.053
0.085
0.096
0.026 typ.
0.047
0.055
0.021 ref.
0.010
0.018
0°
8°
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-17
Package Outlines (continued)
DIMENSIONS, SOIC-8L
A2
A
A1
D
b
Symbol
e
A
A1
A2
b
C
D
E
E1
e
L
θ
L
E
E1
θ
Dimensions
In Millimeters
Min
Max
1.370
1.670
0.070
0.170
1.300
1.500
0.306
0.506
0.203 TYP.
4.700
5.100
3.820
4.020
5.800
6.200
1.270 TYP.
0.450
0.750
0°
8°
Dimensions
In Inches
Min
Max
0.054
0.066
0.003
0.007
0.051
0.059
0.012
0.020
0.008 TYP.
0.185
0.201
0.150
0.158
0.228
0.244
0.050 TYP.
0.018
0.030
0°
8°
C
RECOMMENDED SOLDERING FOOTPRINT, SOIC-8L
8X
5.40
0.213
(1.55)
MAX
(0.061)
(3.90)
MIN
(0.154)
1
(0.60)
MAX 8X
(0.024)
PITCH
1.270
0.050
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
mm
( inches
)
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-18
Package Outlines (continued)
DIMENSIONS, MSOP-8L
A2
A
A1
D
b
Symbol
e
A
A1
A2
b
C
D
E
E1
e
L
θ
L
E1
E
Dimensions
In Millimeters
Min
Max
0.800
1.100
Dimensions
In Inches
Min
Max
0.031
0.043
0.050
0.150
0.750
0.950
0.290
0.380
0.150
0.200
2.900
3.100
2.900
3.100
4.700
5.100
0.650 TYP.
0.400
0.700
0°
8°
0.002
0.006
0.030
0.037
0.011
0.015
0.006
0.008
0.114
0.122
0.114
0.122
0.185
0.201
0.026 TYP.
0.016
0.028
0°
8°
θ
C
RECOMMENDED SOLDERING FOOTPRINT, MSOP-8L
8X
(0.45)
MAX
(0.018)
(1.45)
MAX
(0.057)
8X
4.40
(5.85)
MAX
0.173
(0.230)
(2.95)
MIN
(0.116)
0.65
PITCH
0.026
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
mm
( inches
)
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-19
Package Outlines (continued)
DIMENSIONS, DFN2x2-8L
E
A
c
A1
1
Nd
D1
2
D
b1
Exposed Thermal
Pad Zone
L
h
E1
h
2
e
Symbol
Min.
0.70
A
A1
b
b1
c
D
D1
Nd
E
E1
e
L
h
0.20
0.18
1.90
1.10
1.90
0.60
0.30
0.15
Millimeters
Nom.
0.75
0.02
0.25
0.18 REF
0.20
2.00
1.20
1.50BSC
2.00
0.70
0.50BSC
0.35
0.20
1
b
BOTTOM VIEW
RECOMMENDED SOLDERING FOOTPRINT, DFN2x2-8L
1.60
0.0630
PACKAGE
OUTLINE
8X
0.50
0.0197
1.00
0.0394
2.30
0.0906
1
0.50
PITCH
0.0197
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
0.30
8X 0.0118
mm
( inches
)
Max.
0.80
0.05
0.30
0.25
2.10
1.30
2.10
0.80
0.40
0.25
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-20
Package Outlines (continued)
DIMENSIONS, SOIC-14L
A3
A2
A
A1
D
b
C
e
L1 L
E
Symbol
E1
A
A1
A2
A3
b
C
D
E
E1
e
L1
L
θ
Dimensions
In Millimeters
Min
Max
1.450
1.850
0.100
0.300
1.350
1.550
0.550
0.750
0.406 TYP.
0.203 TYP.
8.630
8.830
5.840
6.240
3.850
4.050
1.270 TYP.
1.040 REF.
0.350
0.750
2°
8°
Dimensions
In Inches
Min
Max
0.057
0.073
0.004
0.012
0.053
0.061
0.022
0.030
0.016 TYP.
0.008 TYP.
0.340
0.348
0.230
0.246
0.152
0.159
0.050 TYP.
0.041 REF.
0.014
0.030
2°
8°
θ
RECOMMENDED SOLDERING FOOTPRINT, SOIC-14L
14X
5.40
0.213
(1.50)
MAX
(0.059)
(3.90)
MIN
(0.154)
1
(0.60)
MAX 14X
(0.024)
PITCH
1.270
0.050
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
mm
( inches
)
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
LTC8701, LTC8702, LTC8703, LTC8704
P-21
Package Outlines (continued)
DIMENSIONS, TSSOP-14L
A3 A2
A
Symbol
A1
D
b
e
C
L1 L
E
E1
A
A1
A2
A3
b
C
D
E
E1
e
L1
L
θ
Dimensions
In Millimeters
Min
Max
1.200
0.050
0.150
0.900
1.050
0.390
0.490
0.200
0.290
0.130
0.180
4.860
5.060
6.200
6.600
4.300
4.500
0.650 TYP.
1.000 REF.
0.450
0.750
0°
8°
Dimensions
In Inches
Min
Max
0.047
0.002
0.006
0.035
0.041
0.015
0.019
0.008
0.011
0.005
0.007
0.191
0.199
0.244
0.260
0.169
0.177
0.026 TYP.
0.039 REF.
0.018
0.030
0°
8°
θ
RECOMMENDED SOLDERING FOOTPRINT, TSSOP-14L
14X
(1.45)
MAX
(0.057)
(4.40)
MIN
(0.173)
PITCH
0.65
0.026
1
5.90
0.232
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
14X
(0.45)
MAX
(0.018)
mm
( inches
)
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
P-22
LTC8701, LTC8702, LTC8703, LTC8704
IMPORTANT NOTICE
Linearin is a global fabless semiconductor company specializing in advanced high-performance high-
quality analog/mixed-signal IC products and sensor solutions. The company is devoted to the innovation
of high performance, analog-intensive sensor front-end products and modular sensor solutions, applied
in multi-market of medical & wearable devices, smart home, sensing of IoT, and intelligent industrial &
smart factory (industrie 4.0). Linearin’s product families include widely-used standard catalog products,
solution-based application specific standard products (ASSPs) and sensor modules that help customers
achieve faster time-to-market products. Go to http://www.linearin.com for a complete list of Linearin
product families.
For additional product information, or full datasheet, please contact with the Linearin’s Sales Department
or Representatives.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Linearin and designs are registered trademarks of Linearin Technology Corporation.
© Copyright Linearin Technology Corporation. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
FN1617-32.1a — Data Sheet
Ultra-Low Power 310nA, 1.7V, RRI, CMOS Input Comparators
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