LT1011/LT1011A
Voltage Comparator
FEATURES
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DESCRIPTION
The LT
®
1011 is a general purpose comparator with sig-
nificantly better input characteristics than the LM111.
Although pin compatible with the LM111, it offers four
times lower bias current, six times lower offset voltage
and five times higher voltage gain. Offset voltage drift,
a previously unspecified parameter, is guaranteed at
15μV/°C. Additionally, the supply current is lower by a factor
of two with no loss in speed. The LT1011 is several times
faster than the LM111 when subjected to large overdrive
conditions. It is also fully specified for DC parameters and
response time when operating on a single 5V supply. These
parametric improvements allow the LT1011 to be used in
high accuracy (≥12-bit) systems without trimming. In a
12-bit A/D application, for instance, using a 2mA DAC, the
offset error introduced by the LT1011 is less than 0.5LSB.
The LT1011 retains all the versatile features of the LM111,
including single 3V to ±18V supply operation, and a float-
ing transistor output with 50mA source/sink capability. It
can drive loads referenced to ground, negative supply or
positive supply, and is specified up to 50V between V
–
and
the collector output. A differential input voltage up to the
full supply voltage is allowed, even with ±18V supplies,
enabling the inputs to be clamped to the supplies with
simple diode clamps.
Pin Compatible with LM111 Series Devices
Guaranteed
Max 0.5mV Input Offset Voltage
Guaranteed
Max 25nA Input Bias Current
Guaranteed
Max 3nA Input Offset Current
Guaranteed
Max 250ns Response Time
Guaranteed
Min 200,000 Voltage Gain
50mA Output Current Source or Sink
±30V Differential Input Voltage
Fully Specified for Single 5V Operation
Available in 8-Lead PDIP and SO Packages
APPLICATIONS
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SAR A/D Converters
Voltage-to-Frequency Converters
Precision RC Oscillator
Peak Detector
Motor Speed Control
Pulse Generator
Relay/Lamp Driver
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
10μs 12-Bit A/D Converter
3.9k
R1
1k
FULL-SCALE
TRIM
R2*
6.49k
15V
LM329
7V
R3
6.98k
–15V
0.001μF
RESPONSE TIME (ns)
INPUT
0V TO 10V
6012
12-BIT
D/A CONVERTER
R4*
2.49k
R5
1k
5V
*R2 AND R4
SHOULD TC TRACK
Response Time vs Overdrive
500
450
400
350
300
250
200
150
100
50
0
0.1
7475
LATCH
1
10
OVERDRIVE (mV)
100
1011 TA02
15V
FALLING
OUTPUT
RISING
OUTPUT
+
R6
820Ω
LT1011A
PARALLEL
OUTPUTS
PARALLEL
OUTPUTS
SERIAL OUTPUT
AM2504
SAR REGISTER
E
S
START
CP
D
CC
S
–
5V
CLOCK f = 1.4MHz
1011 TA01
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LT1011/LT1011A
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (Pin 8 to Pin 4) .................................36V
Output to Negative Supply (Pin 7 to Pin 4)
LT1011AC, LT1011C ..............................................40V
LT1011AI, LT1011I ................................................40V
LT1011AM, LT1011M
(OBSOLETE)
.......................50V
Ground to Negative Supply (Pin 1 to Pin 4) ..............30V
Differential Input Voltage.........................................±36V
Voltage at STROBE Pin (Pin 6 to Pin 8) ......................5V
Input Voltage (Note 2)..........................Equal to Supplies
Output Short-Circuit Duration ...............................10 sec
Operating Temperature Range (Note 3)
LT1011AC, LT1011C ................................. 0°C to 70°C
LT1011AI, LT1011I ............................... –40°C to 85°C
LT1011AM, LT1011M
(OBSOLETE)
.... –55°C to 125°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
PACKAGE/ORDER INFORMATION
ORDER PART NUMBER
TOP VIEW
V
+
8
GND 1
INPUT 2
INPUT 3
+
–
ORDER PART NUMBER
TOP VIEW
GND 1
INPUT 2
INPUT 3
V
–
+
–
7 OUTPUT
BALANCE/
6
STROBE
5 BALANCE
LT1011ACH
LT1011CH
LT1011AMH
LT1011MH
8
7
6
5
V+
OUTPUT
BALANCE/
STROBE
BALANCE
4
LT1011ACN8
LT1011CN8
LT1011CS8
LT1011AIS8
LT1011IS8
S8 PART MARKING
1011
1011AI
1011I
ORDER PART NUMBER
LT1011ACJ8 LT1011AMJ8
LT1011CJ8 LT1011MJ8
4
V
–
H PACKAGE
8-LEAD TO-5 METAL CAN
T
JMAX
= 150°C,
θ
JA
= 150°C/W,
θ
JC
= 45°C/W
N8 PACKAGE
S8 PACKAGE
8-LEAD PDIP
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/W(N8)
T
JMAX
= 150°C,
θ
JA
= 150°C/W(S8)
J8 PACKAGE 8-LEAD CERDIP
T
JMAX
= 150°C,
θ
JA
= 100°C/W(J8)
Consider the N8 or S8 Packages for Alternate Source
OBSOLETE PACKAGES
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.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
OS
Input Offset Voltage
*Input Offset Voltage
CONDITIONS
(Note 4)
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
= ±15V, V
CM
= 0V, R
S
= 0Ω, V
GND
= –15V, output at pin 7 unless
otherwise noted.
LT1011AC/AI/AM
MIN
●
LT1011C/I/M
MIN
TYP
0.6
MAX
1.5
3
2
3
UNITS
mV
mV
mV
mV
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TYP
0.3
MAX
0.5
1
0.75
1.5
R
S
≤ 50k (Note 5)
●
*Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5.
2
LT1011/LT1011A
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
I
OS
I
B
*Input Offset Current
Input Bias Current
*Input Bias Current
ΔV
OS
ΔT
A
VOL
Input Offset Voltage Drift
(Note 6)
*Large-Signal Voltage Gain
CONDITIONS
(Note 5)
●
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
= ±15V, V
CM
= 0V, R
S
= 0Ω, V
GND
= –15V, output at pin 7 unless
otherwise noted.
LT1011AC/AI/AM
MIN
TYP
0.2
15
20
●
●
LT1011C/I/M
MIN
TYP
0.2
20
25
4
200
50
500
300
MAX
4
6
50
65
80
25
UNITS
nA
nA
nA
nA
nA
μV/°C
V/mV
V/mV
MAX
3
5
25
35
50
15
(Note 4)
(Note 5)
T
MIN
≤ T ≤ T
MAX
R
L
= 1k Connected to 15V,
–10V ≤ V
OUT
≤ 14.5V
R
L
= 500Ω Connected to 5V,
V
S
= Single 5V, V
GND
= 0V,
0.5V ≤ V
OUT
≤ 4.5V
4
200
50
500
300
CMRR
Common Mode Rejection Ratio
*Input Voltage Range (Note 9)
V
S
= ±15V
V
S
= Single 5V
(Note 7)
V
IN
= –5mV, I
SINK
= 8mA, T
J
≤ 100°C
V
IN
= –5mV, I
SINK
= 8mA
V
IN
= –5mV, I
SINK
= 50mA
V
IN
= 5mV, V
GND
= –15V,
V
OUT
= 20V
V
GND
= 0
V
GND
= 0
Minimum to Ensure Output Transistor is Off,
V
GND
= 0
●
●
●
94
●
–14.5
●
0.5
115
13
3
150
0.25
0.25
0.7
0.2
3.2
1.7
250
0.4
0.45
1.5
10
500
4
2.5
90
–14.5
0.5
115
13
3
150
0.25
0.25
0.7
0.2
3.2
1.7
250
0.4
0.45
1.5
10
500
4
2.5
dB
V
V
ns
V
V
V
nA
nA
mA
mA
μA
t
D
V
OL
*Response Time
*Output Saturation Voltage,
V
GND
= 0
*Output Leakage Current
*Positive Supply Current
*Negative Supply Current
*Strobe Current (Note 8)
Input Capacitance
500
6
500
6
pF
*Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5.
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.
Note 2:
Inputs may be clamped to supplies with diodes so that
maximum input voltage actually exceeds supply voltage by one diode
drop. See Input Protection in the Applications Information section.
Note 3:
T
JMAX
= 150°C.
Note 4:
Output is sinking 1.5mA with V
OUT
= 0V.
Note 5:
These specifications apply for all supply voltages from a single
5V to ±15V, the entire input voltage range, and for both high and low
output states. The high state is I
SINK
= 100μA, V
OUT
= (V
+
– 1V) and
the low state is I
SINK
= 8mA, V
OUT
= 0.8V. Therefore, this specification
defines a worst-case error band that includes effects due to common
mode signals, voltage gain and output load.
Note 6:
Drift is calculated by dividing the offset voltage difference
measured at min and max temperatures by the temperature difference.
Note 7:
Response time is measured with a 100mV step and 5mV
overdrive. The output load is a 500Ω resistor tied to 5V. Time
measurement is taken when the output crosses 1.4V.
Note 8:
Do not short the STROBE pin to ground. It should be current
driven at 3mA to 5mA for the shortest strobe time. Currents as low
as 500μA will strobe the LT1011A if speed is not important. External
leakage on the STROBE pin in excess of 0.2μA when the strobe is “off”
can cause offset voltage shifts.
Note 9:
See graph “Input Offset Voltage vs Common Mode Voltage.”
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LT1011/LT1011A
TYPICAL PERFORMANCE CHARACTERISTICS
Input Bias Current
45
I
B
FLOWS OUT
40 OF INPUTS
35
CURRENT (nA)
CURRENT (nA)
30
25
20
15
10
5
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G01
Input Offset Current
0.9
EQUIVALENT OFFSET VOLTAGE (mV)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G02
Worst-Case Offset Error
100
10
LM311
(FOR COMPARISON)
LT1011M
LT1011C
1
LT1011AM
LT1011AC
0.1
1k
10k
100k
SOURCE RESISTANCE (Ω)
1M
1011 G03
Input Characteristics*
5
0
INPUT CURRENT (nA)
–5
–10
–15
–20
–25
–30
–35
–40
0
5
10
–20 –15 –10 –5
INPUT VOLTAGE (V)
15
20
COMMON MODE VOLTAGE (V)
*EITHER INPUT.
REMAINING INPUT GROUNDED.
CURRENT FLOWS OUT OF INPUT.
V
S
= ±15V
V
+
–0.5
Common Mode Limits
50
Transfer Function (Gain)
T
A
= 25°C
COLLECTOR
OUTPUT
R
L
= 1k
–1.5
–2.0
0.4
0.3
0.2
0.1
V
–
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G05
OUTPUT VOLTAGE (V)
–1.0
POSITIVE LIMIT
40
30
REFERRED TO SUPPLIES
20
NEGATIVE LIMIT
10
EMITTER
OUTPUT
R
L
= 600Ω
–0.3
0.1
0.3
–0.1
DIFFERENTIAL INPUT VOLTAGE (mV)
0.5
0
– 0.5
1011 G04
1011 G06
Response Time—Collector Output
6
5
4
3
2
1
0
V
S
= ±15V
OVERDRIVE
20mV
5mV
2mV
6
5
4
15V
V
IN
5V
500Ω
Response Time—Collector Output
V
S
= ±15V
V
IN
Collector Output Saturation
Voltage
1.0
0.9
SATURATION VOLTAGE (V)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
5
10 15 20 25 30 35 40 45 50
SINK CURRENT (mA)
1011 G09
15V
5V
500Ω
PIN 1 GROUNDED
–
+
–15V
3
2
1
–
+
–15V
OVERDRIVE
20mV
5mV
2mV
T
A
= 125°C
T
A
= 25°C
0
T
A
= –55°C
100mV
0
0
INPUT = 100mV STEP
100mV
0
0
INPUT = 100mV STEP
50 100 150 200 250 300 350 400 450
TIME (ns)
1011 G07
50 100 150 200 250 300 350 400 450
TIME (ns)
1011 G08
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LT1011/LT1011A
TYPICAL PERFORMANCE CHARACTERISTICS
Response Time Using GND Pin
as Output
15
INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V)
INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V)
10
5
0
–5
–10
–15
0
–50
–100
0
1
2
TIME (μs)
V
S
= ±15V
T
A
= 25°C
3
4
1011 G10
Response Time Using GND Pin
as Output
15
V
+
V
IN
V
OUT
2k
V
–
Output Limiting Characteristics*
140
SHORT-CIRCUIT CURRENT (mA)
120
100
80
60
40
20
0
*MEASURED 3 MINUTES
AFTER SHORT
0
10
5
OUTPUT VOLTAGE (V)
15
1011 G12
T
A
= 25°C
POWER
DISSIPATION
0.7
0.6
POWER DISSIPATION (W)
0.5
0.4
SHORT-CIRCUIT
CURRENT
0.3
0.2
0.1
0
20mV
5mV
2mV
V
+
V
IN
V
OUT
2k
V
–
10
5
0
–5
–10
–15
0
–50
–100
0
1
20mV
5mV
2mV
V
S
= ±15V
T
A
= 25°C
2
TIME (μs)
3
4
1011 G11
Supply Current vs Supply Voltage
5
6
5
CURRENT (mA)
POSITIVE SUPPLY
COLLECTOR OUTPUT “LO”
3
POSITIVE AND NEGATIVE SUPPLY
COLLECTOR OUTPUT “HI”
4
3
2
1
Supply Current vs Temperature
10
–7
Output Leakage Current
V
S
= ±15V
4
CURRENT (mA)
POSITIVE SUPPLY
COLLECTOR OUTPUT “LO”
LEAKAGE CURRENT (A)
10
–8
V
OUT
= 35V
V
GND
= –15V
10
–9
2
10
–10
1
POSITIVE AND NEGATIVE SUPPLY
COLLECTOR OUTPUT “HI”
50
25
75
0
TEMPERATURE (˚C)
100
125
10
–11
25
45
65
85
TEMPERATURE (°C)
105
125
1011 G15
0
0
5
10
15
20
SUPPLY VOLTAGE (V)
25
30
1011 G13
0
–50 –25
1011 G14
Output Saturation—
Ground Output
5
V
+
TO GROUND PIN VOLTAGE (V)
REFERRED TO V
+
0.6
Output Saturation Voltage
8
V
+
7
Response Time vs Input Step Size
1000
V
S
= ±15V
R
L
= 500Ω TO 5V
OVERDRIVE = 5mV
5V
+
4
2
I
SINK
= 8mA
T
J
= 125°C
3
1 R
L
4
V
–
V
OUT
SATURATION VOLTAGE (V)
PROPAGATION DELAY (ns)
LT1011
0.5
0.4
0.3
0.2
0.1
0
0
1
T
J
= 25°C
T
J
= –55°C
800
3
2
T
J
= 25°C
T
J
= 125°C
400
1
200
0
0
10
30
40
20
OUTPUT CURRENT (mA)
50
1011 G16
6
5
2
4
3
INPUT OVERDRIVE (mV)
0
7
8
0
1
2
1011 G17
+
3
T
J
= –55°C
600
INPUT
2
–
1
3
500Ω
7
RISING INPUT
FALLING INPUT
4 5 6 7
INPUT STEP (V)
8
9
10
1011 G18
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PCB Design
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