LINER LT1011ACJ8 Voltage comparator Datasheet

LT1011/LT1011A
Voltage Comparator
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FEATURES
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DESCRIPTIO
The LT ®1011 is a general purpose comparator with significantly 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 floating 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
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APPLICATIO S
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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
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
10µs 12-Bit A/D Converter
3.9k
15V
LM329
7V
R3
6.98k
450
16
17
INPUT
0V TO 10V
19
6012
12-BIT
D/A CONVERTER
12 11 10 9
8
7
6
5
18
4
3
2
5V
R4*
2.49k
R6
820Ω
1
PARALLEL
OUTPUTS
2
5
6
7
8
9
16 17 18 19 20 21
AM2504
SAR REGISTER
24
E
S
D
5V
R5
1k
+
LT1011A
3
PARALLEL
OUTPUTS
4
500
0.001µF
15
13
Response Time vs Overdrive
*R2 AND R4
SHOULD TC TRACK
–15V
7
–
400
RESPONSE TIME (ns)
R1
1k
FULL-SCALE
TRIM
R2*
6.49k
15V
20
14
350
300
250
200
150
FALLING
OUTPUT
RISING
OUTPUT
100
50
SERIAL OUTPUT
0
0.1
7475
LATCH
CC
CP S
1
10
OVERDRIVE (mV)
100
1011 TA02
12
START
CLOCK f = 1.4MHz
1011 TA01
1
LT1011/LT1011A
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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
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PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
V+
8
7 OUTPUT
GND 1
INPUT 2
+
–
6
BALANCE/
STROBE
5 BALANCE
4
V–
H PACKAGE
8-LEAD TO-5 METAL CAN
INPUT 3
GND 1
INPUT 2
LT1011ACH
LT1011CH
LT1011AMH
LT1011MH
ORDER PART NUMBER
TOP VIEW
INPUT 3
+
–
V+
7
OUTPUT
BALANCE/
STROBE
BALANCE
6
V– 4
N8 PACKAGE
8-LEAD PDIP
8
5
LT1011ACN8
LT1011CN8
LT1011CS8
LT1011AIS8
LT1011IS8
S8 PACKAGE
8-LEAD PLASTIC SO
S8 PART MARKING
TJMAX = 150°C, θJA = 130°C/ W(N8)
TJMAX = 150°C, θJA = 150°C/ W(S8)
TJMAX = 150°C, θJA = 150°C/ W, θJC = 45°C/ W
1011
1011AI
1011I
ORDER PART NUMBER
J8 PACKAGE 8-LEAD CERDIP
TJMAX = 150°C, θJA = 100°C/ W(J8)
LT1011ACJ8 LT1011AMJ8
LT1011CJ8 LT1011MJ8
OBSOLETE PACKAGES
Consider the N8 or S8 Packages for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VS = ±15V, VCM = 0V, RS = 0Ω, V1 = –15V, output at pin 7 unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
VOS
Input Offset Voltage
(Note 4)
*Input Offset Voltage
IOS
*Input Offset Current
LT1011AC/AI/AM
MIN
TYP
MAX
LT1011C/I/M
MIN
TYP
MAX
0.3
0.6
●
0.5
1.0
●
0.75
1.50
RS ≤ 50k (Note 5)
(Note 5)
0.2
●
IB
3
5
1.5
3.0
mV
mV
2.0
3.0
mV
mV
4
6
nA
nA
Input Bias Current
(Note 4)
15
25
20
50
nA
*Input Bias Current
(Note 5)
20
35
50
25
65
80
nA
nA
●
*Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5.
2
0.2
UNITS
LT1011/LT1011A
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwide specifications are at TA = 25°C.
VS = ±15V, VCM = 0V, RS = 0Ω, V1 = –15V, output at pin 7 unless otherwise noted.
LT1011AC/AI/AM
MIN
TYP
MAX
LT1011C/I/M
MIN
TYP
MAX
UNITS
4
4
µV/°C
SYMBOL
PARAMETER
CONDITIONS
∆VOS
∆T
Input Offset Voltage Drift
(Note 6)
TMIN ≤ T ≤ TMAX
AVOL
*Large-Signal Voltage Gain
RL = 1k to 15V,
–10V ≤ VOUT ≤ 14.5V
200
500
200
500
V/mV
RL = 500Ω to 5V,
0.5V ≤ VOUT ≤ 4.5V
50
300
50
300
V/mV
94
115
90
115
dB
CMRR
●
Common Mode
Rejection Ratio
*Input Voltage Range
(Note 9)
VS = ±15V
VS = Single 5V
tD
*Response Time
(Note 7)
VOL
*Output Saturation Voltage,
V1 = 0
VIN = 5mV, ISINK = 8mA, TJ ≤ 100°C
VIN = 5mV, ISINK = 8mA
VIN = 5mV, ISINK = 50mA
●
●
*Output Leakage Current
VIN = 5mV, V1 = –15V,
VOUT = 35V (25V for LT1011C/I)
●
●
●
–14.5
0.5
*Positive Supply Current
*Negative Supply Current
*Strobe Current
(Note 8)
Minimum to Ensure Output
Transistor is Off
Input Capacitance
15
13
3
–14.5
0.5
25
13
3
V
V
150
250
150
250
ns
0.25
0.25
0.70
0.40
0.45
1.50
0.25
0.25
0.70
0.40
0.45
1.50
V
V
V
0.2
10
500
0.2
10
500
nA
nA
3.2
4.0
3.2
4.0
mA
1.7
2.5
1.7
2.5
mA
500
µA
500
6
6
pF
*Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5.
Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
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: TJMAX = 150°C.
Note 4: Output is sinking 1.5mA with VOUT = 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 ISINK ≥ 100µA, VOUT ≥ (V + – 1V) and
the low state is ISINK ≤ 8mA, VOUT ≤ 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
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Bias Current
Input Offset Current
45
IB FLOWS OUT
OF INPUTS
35
0.7
30
0.6
25
20
15
0.5
0.4
0.3
10
0.2
5
0.1
0
– 50 – 25
0
EQUIVALENT OFFSET VOLTAGE (mV)
0.8
CURRENT (nA)
0
– 50 – 25
25 50 75 100 125 150
TEMPERATURE (°C)
Input Characteristics*
TA = 25°C
– 25
– 30
–1.5
– 2.0
REFERRED TO SUPPLIES
0.4
0.3
NEGATIVE LIMIT
0.2
COLLECTOR
OUTPUT
RL = 1k
40
OUTPUT VOLTAGE (V)
COMMON MODE VOLTAGE (V)
INPUT CURRENT (nA)
– 20
POSITIVE LIMIT
–1.0
30
20
10
EMITTER
OUTPUT
RL = 600Ω
0.1
– 35
– 40
0
5
10
– 20 –15 –10 – 5
INPUT VOLTAGE (V)
15
20
V–
– 50 – 25
0
1011 G05
Response Time—Collector Output
Response Time—Collector Output
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OVERDRIVE
20mV
5mV
2mV
4
3
2
5
15V
VIN
–
5V
500Ω
1
15V
VIN
OVERDRIVE
20mV
5mV
2mV
3
2
–
–15V
+
0
0
–15V
100mV
100mV
INPUT = 100mV STEP
0
INPUT = 100mV STEP
0
PIN 1 GROUNDED
0.9
500Ω
1
0.5
Collector Output Saturation
Voltage
5V
+
– 0.3
0.1
0.3
– 0.1
DIFFERENTIAL INPUT VOLTAGE (mV)
1011 G06
1.0
VS = ±15V
4
0
– 0.5
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G04
VS = ±15V
1M
Transfer Function (Gain)
50
– 0.5
–15
5
10k
100k
SOURCE RESISTANCE (Ω)
1011 G03
Common Mode Limits
*EITHER INPUT.
REMAINING INPUT GROUNDED.
CURRENT FLOWS OUT OF INPUT.
VS = ± 15V
LT1011AM
LT1011AC
1
1k
V+
–10
6
LT1011M
LT1011C
1011 G01
5
–5
10
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G01
0
LM311
(FOR COMPARISON)
0.1
0
SATURATION VOLTAGE (V)
CURRENT (nA)
40
Worst-Case Offset Error
100
0.9
0.8
TA = 125°C
0.7
TA = 25°C
0.6
0.5
0.4
TA = – 55°C
0.3
0.2
0.1
0
0
50 100 150 200 250 300 350 400 450
TIME (ns)
1011 G07
4
0
50 100 150 200 250 300 350 400 450
TIME (ns)
1011 G08
0
5
10 15 20 25 30 35 40 45 50
SINK CURRENT (mA)
1011 G09
LT1011/LT1011A
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TYPICAL PERFOR A CE CHARACTERISTICS
Response Time Using GND Pin
as Output
V+
20mV
10
5mV
2mV
V+
5
VIN
0
–5
VOUT
–10
2k
–15
V
0
–
– 50
VS = ±15V
TA = 25°C
–100
0
1
4
3
2
TIME (µs)
INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V)
15
VIN
10
5
VOUT
0
2k
–5
V–
–10
5mV
20mV
–15
2mV
0
VS = ±15V
TA = 25°C
– 50
–100
0
1
2
TIME (µs)
1011 G10
Supply Current vs Supply Voltage
0.4
60
0.3
SHORT-CIRCUIT
CURRENT
0.2
40
20
0.1
*MEASURED 3 MINUTES
AFTER SHORT
10
5
OUTPUT VOLTAGE (V)
0
15
0
1011 G12
Output Leakage Current
10 –7
VS = ±15V
3
POSITIVE AND NEGATIVE SUPPLY
COLLECTOR OUTPUT “HI”
POSITIVE SUPPLY
COLLECTOR OUTPUT “LO”
3
2
1
0
5
25
10
15
20
SUPPLY VOLTAGE (V)
REFERRED TO V +
1 RL
4
V–
2
VOUT
TJ = 25°C
TJ = 125°C
1
TJ = 125°C
0.4
TJ = 25°C
0.3
0.2
TJ = – 55°C
0
10
30
40
20
OUTPUT CURRENT (mA)
50
1011 G16
65
85
TEMPERATURE (°C)
105
0
1
5
6
2
3
4
INPUT OVERDRIVE (mV)
125
Response Time vs Input Step Size
1000
0.1
0
45
1011 G15
0.5
7
LT1011
TJ = – 55°C
25
ISINK = 8mA
V+
8
SATURATION VOLTAGE (V)
2
3
3
125
Output Saturation Voltage
0.6
4
100
1011 G14
Output Saturation—
Ground Output
+
10 –10
10 –11
50
25
75
0
TEMPERATURE (˚C)
1011 G13
5
VOUT = 35V
VGND = –15V
10 –9
POSITIVE AND NEGATIVE SUPPLY
COLLECTOR OUTPUT “HI”
0
–50 –25
30
10 –8
PROPAGATION DELAY (ns)
2
4
LEAKAGE CURRENT (A)
5
POSITIVE SUPPLY
COLLECTOR OUTPUT “LO”
CURRENT (mA)
CURRENT (mA)
0.5
80
Supply Current vs Temperature
1
V + TO GROUND PIN VOLTAGE (V)
100
6
4
0
0.6
POWER
DISSIPATION
1011 G11
5
0
120
0
4
3
0.7
TA = 25°C
POWER DISSIPATION (W)
INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V)
15
Output Limiting Characteristics*
140
SHORT-CIRCUIT CURRENT (mA)
Response Time Using GND Pin
as Output
7
8
1011 G17
VS = ± 15V
RL = 500Ω TO 5V
OVERDRIVE = 5mV
800
5V
INPUT
600
3
–
2
+
500Ω
7
1
400
RISING INPUT
FALLING INPUT
200
0
0
1
2
3
4 5 6 7
INPUT STEP (V)
8
9
10
1011 G18
5
LT1011/LT1011A
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Offset Voltage
vs Common Mode Voltage
INPUT OFFSET VOLTAGE (mV)
2.0
Offset Pin Characteristics
CHANGE IN VOS (mV/µA)
2.5
TJ = 25°C
1.5
UPPER
COMMON MODE
+
LIMIT = V – (1.5V)
1.0
0.5
0
0.8
0.6
0.4
0.2
0
– 0.5
–150mV
–1.0
– 2.0
– 2.5
VOLTAGE ON PINS 5 AND 6
WITH RESPECT TO V +
–100mV
V – (OR GND WITH
SINGLE SUPPLY)
–1.5
CHANGE IN VOS FOR CURRENT
INTO PINS 5 OR 6
– 50mV
V – 0.1 0.2 0.3 0.4 0.5 0.6 0.7
COMMON MODE VOLTAGE (V)
V+
1011 G19
0
– 50 – 25
0
25 50 75 100 125 150
TEMPERATURE (°C)
1011 G20
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APPLICATIONS INFORMATION
Preventing Oscillation Problems
Oscillation problems in comparators are nearly always
caused by stray capacitance between the output and
inputs or between the output and other sensitive pins on
the comparator. This is especially true with high gain
bandwidth comparators like the LT1011, which are
designed for fast switching with millivolt input signals.
The gain bandwidth product of the LT1011 is over 10GHz.
Oscillation problems tend to occur at frequencies around
5MHz, where the LT1011 has a gain of ≈ 2000. This
implies that attenuation of output signals must be at
least 2000:1 at 5MHz as measured at the inputs. If the
source impedance is 1kΩ, the effective stray capacitance between output and input must have a reactance
of more than (2000)(1kΩ) = 2MΩ, or less than 0.02pF.
The actual interlead capacitance between input and output pins on the LT1011 is less than 0.002pF when cut to
printed circuit mount length. Additional stray capacitance due to printed circuit traces must be minimized by
routing the output trace directly away from input lines
and, if possible, running ground traces next to input
traces to provide shielding. Additional steps to ensure
oscillation-free operation are:
1. Bypass the STROBE/BALANCE pins with a 0.01µF
capacitor connected from Pin 5 to Pin 6. This eliminates stray capacitive feedback from the output to the
6
BALANCE pins, which are nearly as sensitive as the
inputs.
2. Bypass the negative supply (Pin 4) with a 0.1µF
ceramic capacitor close to the comparator. 0.1µF can
also be used for the positive supply (Pin 8) if the pullup load is tied to a separate supply. When the pull-up
load is tied directly to Pin 8, use a 2µF solid tantalum
bypass capacitor.
3. Bypass any slow moving or DC input with a capacitor
(≥ 0.01µF) close to the comparator to reduce high
frequency source impedance.
4. Keep resistive source impedance as low as possible. If
a resistor is added in series with one input to balance
source impedances for DC accuracy, bypass it with a
capacitor. The low input bias current of the LT1011
usually eliminates any need for source resistance balancing. A 5kΩ imbalance, for instance, will create only
0.25mV DC offset.
5. Use hysteresis. This consists of shifting the input
offset voltage of the comparator when the output
changes state. Hysteresis forces the comparator to
move quickly through its linear region, eliminating
oscillations by “overdriving” the comparator under all
input conditions. Hysteresis may be either AC or DC.
AC techniques do not shift the apparent offset voltage
LT1011/LT1011A
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APPLICATIONS INFORMATION
15V
2µF
TANT
+
8
C8 TO C6 = 0.003µF
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INPUT OFFSET VOLTAGE (mV)
of the comparator, but require a minimum input signal
slew rate to be effective. DC hysteresis works for all
input slew rates, but creates a shift in offset voltage
dependent on the previous condition of the input signal. The circuit shown in Figure 1 is an excellent
compromise between AC and DC hysteresis.
6
5
4
3
2
OUTPUT “LO” TO “HI”
1
0
OUTPUT “HI” TO “LO”
–1
3
INPUTS
2
–
+
C1
0.003µF
8
6
LT1011
5 7
R2
15M
RL
(50kHz)
–2
(5kHz)
10
100
TIME/FREQUENCY (µs)
1
1000
1011 F02
OUTPUT
1
Figure 2. Input Offset Voltage vs Time to Last Transition
4
–15V
0.1µF
1011 F01
Figure 1. Comparator with Hysteresis
This circuit is especially useful for general purpose
comparator applications because it does not force any
signals directly back onto the input signal source.
Instead, it takes advantage of the unique properties of
the BALANCE pins to provide extremely fast, clean
output switching even with low frequency input signals in the millivolt range. The 0.003µF capacitor from
Pin 6 to Pin 8 generates AC hysteresis because the
voltage on the BALANCE pins shifts slightly, depending on the state of the output. Both pins move about
4mV. If one pin (6) is bypassed, AC hysteresis is
created. It is only a few millivolts referred to the inputs, but is sufficient to switch the output at nearly the
maximum speed of which the comparator is capable.
To prevent problems from low values of input slew
rate, a slight amount of DC hysteresis is also used. The
sensitivity of the BALANCE pins to current is about
0.5mV input referred offset for each microampere of
BALANCE pin current. The 15M resistor tied from
OUTPUT to Pin 5 generates 0.5mV DC hysteresis. The
combination of AC and DC hysteresis creates clean
oscillation-free switching with very small input errors.
Figure 2 plots input referred error versus switching
frequency for the circuit as shown.
Note that at low frequencies, the error is simply the DC
hysteresis, while at high frequencies, an additional
error is created by the AC hysteresis. The high
frequency error can be reduced by reducing CH, but
lower values may not provide clean switching with
very low slew rate input signals.
Input Protection
The inputs to the LT1011 are particularly suited to general
purpose comparator applications because large differential and/or common mode voltages can be tolerated without damage to the comparator. Either or both inputs can
be raised 40V above the negative supply, independent of
the positive supply voltage. Internal forward biased diodes
will conduct when the inputs are taken below the negative
supply. In this condition, input current must be limited to
1mA. If very large (fault) input voltages must be accommodated, series resistors and clamp diodes should be
used (see Figure 3).
V+
R1**
INPUTS
D1
D2
R3*
300Ω 3
R4*
300Ω 2
R2**
D3
–
8
LT1011
+
4
D4
D1 TO D4: 1N4148
*MAY BE ELIMINATED FOR IFAULT ≤ 1mA
**SELECT ACCORDING TO ALLOWABLE
FAULT CURRENT AND POWER DISSIPATION
V–
1011 F03
Figure 3. Limiting Fault Input Currents
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LT1011/LT1011A
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APPLICATIONS INFORMATION
The input resistors should limit fault current to a reasonable value (0.1mA to 20mA). Power dissipation in the
resistors must be considered for continuous faults, especially when the LT1011 supplies are off. One final caution:
lightly loaded supplies may be forced to higher voltages by
large fault currents flowing through D1-D4.
15V
5V
8
–
RL
7
LT1011
6
4
TTL OR
CMOS DRIVE
(5V SUPPLY)
–15
R3 and R4 limit input current to the LT1011 to less than
1mA when the input signals are held below V –. They may
be eliminated if R1 and R2 are large enough to limit fault
current to less than 1mA.
OUTPUT
1
+
3k
1011 F04
Figure 4. Typical Strobe Circuit
Input Slew Rate Limitations
The response time of a comparator is typically measured
with a 100mV step and a 5mV to 10mV overdrive. Unfortunately, this does not simulate many real world situations
where the step size is typically much larger and overdrive
can be significantly less. In the case of the LT1011, step
size is important because the slew rate of internal nodes
will limit response time for input step sizes larger than 1V.
At 5V step size, for instance, response time increases from
150ns to 360ns. See the curve “Response Time vs Input
Step Size for more detail.
If response time is critical and large input signals are
expected, clamp diodes across the inputs are recommended. The slew rate limitation can also affect performance when differential input voltage is low, but both
inputs must slew quickly. Maximum suggested common
mode slew rate is 10V/µs.
level inputs. A 1pF capacitor between the output and Pin 5
will greatly reduce oscillation problems without reducing
strobe speed.
DC hysteresis can also be added by placing a resistor from
output to Pin 5. See step 5 under “Preventing Oscillation
Problems.”
The pin (6) used for strobing is also one of the offset adjust
pins. Current flow into or out of Pin 6 must be kept very low
(< 0.2µA) when not strobing to prevent input offset voltage
shifts.
Output Transistor
The LT1011 output transistor is truly floating in the sense
that no current flows into or out of either the collector or
emitter when the transistor is in the “off” state. The
equivalent circuit is shown in Figure 5.
Strobing
The LT1011 can be strobed by pulling current out of the
STROBE pin. The output transistor is forced to an “off”
state, giving a “hi” output at the collector (Pin 7). Currents
as low as 250µA will cause strobing, but at low strobe
currents, strobe delay will be 200ns to 300ns. If strobe
current is increased to 3mA, strobe delay drops to about
60ns. The voltage at the STROBE pin is about 150mV below
V + at zero strobe current and about 2V below V + for 3mA
strobe current. Do not ground the STROBE pin. It must be
current driven. Figure 4 shows a typical strobe circuit.
Note that there is no bypass capacitor between Pins 5 and
6. This maximizes strobe speed, but leaves the comparator more sensitive to oscillation problems for slow, low
8
V+
I1
0.5mA
D1
D2
COLLECTOR
(OUTPUT)
Q1
R1
170Ω
V–
Q2
R2
470Ω
OUTPUT
TRANSISTOR
EMITTER
(GND PIN)
Figure 5. Output Transistor Circuitry
1011 F05
LT1011/LT1011A
U
W
U
U
APPLICATIONS INFORMATION
to V +, the voltage at the emitter in the “on” state is about
2V below V + (see curves).
In the “off” state, I1 is switched off and both Q1 and Q2 turn
off. The collector of Q2 can be now held at any voltage
above V – without conducting current, including voltages
above the positive supply level. Maximum voltage above
V – is 50V for the LT1011M and 40V for the LT1011C/I. The
emitter can be held at any voltage between V + and V – as
long as it is negative with respect to the collector.
Input Signal Range
The common mode input voltage range of the LT1011 is
about 300mV above the negative supply and 1.5V below
the positive supply, independent of the actual supply
voltages (see curve in the Typical Performance Characteristics). This is the voltage range over which the output will
respond correctly when the common mode voltage is
applied to one input and a higher or lower signal is applied
to the remaining input. If one input is inside the common
mode range and one is outside, the output will be correct.
If the inputs are outside the common mode range in
opposite directions, the output will still be correct. If both
inputs are outside the common mode range in the same
direction, the output will not respond to the differential
input; for temperatures of 25°C and above, the output will
remain unconditionally high (collector output), for temperatures below 25°C, the output becomes undefined.
In the “on” state, I1 is connected, turning on Q1 and Q2.
Diodes D1 and D2 prevent deep saturation of Q2 to
improve speed and also limit the drive current of Q1. The
R1/R2 divider sets the saturation voltage of Q2 and provides turn-off drive. Either the collector or emitter pin can
be held at a voltage between V + and V –. This allows the
remaining pin to drive the load. In typical applications, the
emitter is connected to V – or ground and the collector
drives a load tied to V + or a separate positive supply.
When the emitter is used as the output, the collector is
typically tied to V + and the load is connected to ground or
V –. Note that the emitter output is phase reversed with
respect to the collector output so that the “+” and “–” input
designations must be reversed. When the collector is tied
U
TYPICAL APPLICATIONS
Offset Balancing
Driving Load Referenced
to Positive Supply
R2
3k
V+
R1
20k
V+
5
2
+
8
–
2
8
7
V+
V ++
7
LT1011
3
4
V
8
–
INPUTS*
1
+
2
RLOAD
7
LT1011
6
LT1011
3
3
Driving Load Referenced
to Negative Supply
1
+
RLOAD
4
V
–
1011 TA03
V
OR
GROUND
V
V ++ CAN BE GREATER OR LESS THAN V +
1011 TA05
1011 TA06
*INPUT POLARITY IS REVERSED
WHEN USING PIN 1 AS OUTPUT
9
LT1011/LT1011A
U
TYPICAL APPLICATIONS
Strobing
Driving Ground Referred Load
+
7
LT1011
3
V+
V ++**
V+
2
Window Detector
–
2
INPUTS*
6
L1
4
V–
1k
NOTE: DO NOT GROUND STROBE PIN
–
OUTPUT HIGH
INSIDE “WINDOW”
AND LOW ABOVE
HIGH LIMIT OR
BELOW LOW LIMIT
1
VIN
2
1011 TA07
*INPUT POLARITY IS REVERSED
WHEN USING PIN 1 AS OUTPUT
**V ++ MAY BE ANY VOLTAGE ABOVE V –.
PIN 1 SWINGS TO WITHIN ≈ 2V OF V++
1011 TA04
7
LT1011
3
1
+
RL
+
7
LT1011
3
TTL
STROBE
2
HIGH
LIMIT
8
–
+
7
LT1011
3
LOW
LIMIT
–
1
1011 TA08
Crystal Oscillator
Using Clamp Diodes to Improve Frequency Response*
CURRENT MODE
INPUT
(DAC, ETC)
2
D1
+
LT1011
D2
3
5V
10k
7
OUTPUT
–
2
VOLTAGE
INPUT
85kHz
100pF
*SEE CURVE, “RESPONSE TIME vs INPUT STEP SIZE”
OUT
4
–
GROUND OR
LOW IMPEDANCE
REFERENCE
50k
7
LT1011
3
R1
1k
8
+
1
10k
1011 TA09
10k
1011 TA10
Noise Immune 60Hz Line Sync**
High Efficiency** Motor Speed Controller
15V
5V
R3
1k
R2
75k
2VRMS
TO
25VRMS
60Hz
INPUT
C1
50µF
+
R1
1k
Q1
2N6667
5V
R1*
330k
3
C1
0.22µF
8
–
1N4002
7
LT1011
2
1
+
4
MOTOR-TACH
GLOBE 397A120-2
OUTPUT
60Hz
R4
27k
R2
470Ω
R3*
10k
MOTOR TACH
R6
27k
15V
5V
1011 TA11
R5
10k
*INCREASE R1 FOR LARGER INPUT VOLTAGES
**LT1011 SELF OSCILLATES AT ≈ 60Hz CAUSING
IT TO “LOCK” ONTO INCOMING LINE SIGNAL
8
+
7
2
LT1011
1
–
3
C2*
0.1µF
R5
100k
R6
2k
C3
0.1µF
R7
1k
1011 TA12
R4
1k
4
*R3/C2 DETERMINES OSCILLATION
– 5V TO
FREQUENCY OF CONTROLLER
–15V 0V TO 10V
**Q1 OPERATES IN SWITCH MODE
INPUT
10
LT1011/LT1011A
U
TYPICAL APPLICATIONS
Combining Offset Adjust and Strobe
Combining Offset Adjustment and Hystersis
V+
V+
5k
10k
RH*
2RH**
20k
5
–
–
TTL OR CMOS
5V
6
+
LT1011
+
1k
*HYSTERESIS IS ≈ 0.45mV/µA OF
CURRENT CHANGE IN RH
RL **THIS RESISTOR CAUSES HYSTERESIS
TO BE CENTERED AROUND VOS
20k
6
5
7
LT1011
1011 TA15
1
1011 TA13
Direct Strobe Drive When CMOS* Logic
Uses Same V + Supply as LT1011
Low Drift R/C Oscillator †
V+
**
8
–
6
+
15V
2
LT1011
C1
0.015µF
1011 TA14
15V
8
+
1k
7
LT1011
3
*NOT APPLICABLE FOR TTL LOGIC
74HC04
×6
BUFFERED
OUTPUT
4
–
1
Positive Peak Detector
15V
10k*
10k*
15V
2k
INPUT
3
8
7
LT1011
2
2
1
4
10k 3
1M**
*1% METAL FILM
10k*
**TRW TYPE MTR-5/120ppm/°C, 25k ≤ RS ≤ 200k
C1: 0.015µF = POLYSTYRENE, –120ppm/°C,
1011 TA16
± 30ppm WESCO TYPE 32-P
NOTE: COMPARATOR CONTRIBUTES ≤10ppm/°C DRIFT
FOR FREQUENCIES BELOW 10kHz
†
LOW DRIFT AND ACCURATE FREQUENCY ARE
OBTAINED BECAUSE THIS CONFIGURATION
REJECTS EFFECTS DUE TO INPUT OFFSET
VOLTAGE AND BIAS CURRENT OF THE
COMPARATOR
+
C1*
2µF
+
6
LT1008
–
OUTPUT
8
100pF
1011 TA17
–15V
*MYLAR
**SELECT FOR REQUIRED RESET TIME CONSTANT
Negative Peak Detector
15V
2
1M**
2k
INPUT
3
–
1
+
4
–15V
10k
7
LT1011
2
–
8
+
C1*
2µF
100pF
LT1008
3
+
6
OUTPUT
8
1011 TA18
*MYLAR
**SELECT FOR REQUIRED RESET TIME CONSTANT
11
LT1011/LT1011A
U
TYPICAL APPLICATIONS
4-Digit (10,000 Count) A/D Converter
15V
ZERO
TRIM
R1
1k
1
3
R2
18k
INPUT
0V TO 10V
C4
0.01µF
7
R3
3.9k
8
4
D1
D2
6
C1*
0.1µF
C2**
15pF
R6
4.7K
7
OUTPUT = 1 COUNT
PER mV, f = 1MHz
CLOCK
1MHz
1
–
R7
22Ω
5V
C5
0.01µF
+
3
6
5V
8
LT1011
2 5
LF398
15V
R5
4.7k
2
4
–15V
15V
–15V
R4
5.6k
R8
3k
D3
15V
D4
C3
0.1µF
R11
6.8K
R10
1k
R9
FULL-SCALE
3.65k
TRIM
R12
6.8k
2N3904
C6
50pF
LM329
ALL DIODES: 1N4148
*POLYSTYRENE
**NPO
1011 TA19
START
≥12ms
Capacitance to Pulse Width Converter
TH ≥ [CMAX (pF)][1µs/pF]
TL ≥ 10 • CMAX • (1µs/pF)
D1
TTL OR CMOS
(OPERATING
ON 5V)
R2
R1 100k
5k
R3
86.6k
+
GAIN ADJ
5V
8
2
0.01µF
+
10µF†
6
LT1011
3
C**
1
–
)
OUTPUT
1µs/pF
**TYPICAL 2 SECTIONS OF 365pF VARIABLE
CAPACITOR WHEN USED AS SHAFT ANGLE
INDICATION
NEGATIVE SUPPLY IS AVAILABLE (–1V TO –15V)
10µF†
+
1011 TA20
12
R5
4.7k
†THESE COMPONENTS MAY BE ELIMINATED IF
4
D3†
D2†
7
(
*PW = (R2 + R3)(C) R1 + R4 , INPUT CAPACITANCE OF
R1
LT1011 IS ≈ 6pF. THIS IS AN OFFSET TERM.
LT1011/LT1011A
U
TYPICAL APPLICATIONS
Fast Settling* Filter
100pF
1M
15V
2
7
1M
OUTPUT
8
3
VIN
1
4
4.7k
–15V 15V
0.1µF
6
LT1008C
4.7k
1µF
OFM-1A**
–15V
100k
100pF
4
2
8
–
3
1.5k
7 1
LT1011
5
+
6
15V
15V
5k
THRESHOLD
5k
6
+
5 1
LT1011
7
–
10k
8
4
–15V 15V
1011 TA21
100kHz Precision Rectifier
0.033µF
5V
100Ω
AC INPUT
5k
ZERO
CROSS
TRIM
2
8
+
LT1011
3
5V
–
1
5V
1k
7
5V
74C04
12k
820Ω
HP5082-2800
×4
RECTIFIED
OUTPUT
– 5V
4
5V
– 5V
1k
820Ω
74C04
– 5V
12k
– 5V
1011 TA23
13
LT1011/LT1011A
W
W
SCHE ATIC DIAGRA
OFFSET
OFFSET/STROBE
V+
5
6
8
R8
800Ω
Q6
R27
3k
R4
300Ω
R5
160Ω
R1
1.3k
R2
1.3k
Q10
R3
300Ω
R23
4k
Q11
Q5
Q31
Q12
R6
3.2k
D1 D2
Q30
INPUT
(+)
R7
3.2k
Q13
Q29
R11
170Ω
D5
R12
470Ω
Q4
Q27
R16 Q24
800Ω
Q2
Q26
Q25
Q15
Q9 Q19
Q28
3
7
Q20
R22
200Ω
Q1
D7
OUTPUT
Q14
Q3
INPUT
(–)
R10
4k
Q7
Q8
D4
D6
2
R9
800Ω
Q21
Q23
Q16
R17
200Ω
R24
400Ω
R20
940Ω
R13
4Ω
R15
700Ω
Q22
1
Q18
GND
R25
1.6k
R26
1.6k
R19
500Ω
R21
960Ω
R18
275Ω
R14
4.8k
D3
Q17
4
1011 SD
V–
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
H Package
8-Lead TO-5 Metal Can (.230 Inch PCD)
(Reference LTC DWG # 05-08-1321)
OBSOLETE PACKAGE
0.335 – 0.370
(8.509 – 9.398)
DIA
0.305 – 0.335
(7.747 – 8.509)
0.040
(1.016)
MAX
0.027 – 0.045
(0.686 – 1.143)
45°TYP
0.050
(1.270)
MAX
SEATING
PLANE
GAUGE
PLANE
0.010 – 0.045*
(0.254 – 1.143)
0.500 – 0.750
(12.700 – 19.050)
*LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND 0.045" BELOW THE REFERENCE PLANE
0.016 – 0.024
**FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS
(0.406 – 0.610)
PIN 1
0.230
(5.842)
TYP
REFERENCE
PLANE
0.016 – 0.021**
(0.406 – 0.533)
14
0.028 – 0.034
(0.711 – 0.864)
0.165 – 0.185
(4.191 – 4.699)
0.110 – 0.160
(2.794 – 4.064)
INSULATING
STANDOFF
H8 (TO-5) 0.230 PCD 1197
LT1011/LT1011A
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
0.405
(10.287)
MAX
0.005
(0.127)
MIN
0.023 – 0.045
(0.584 – 1.143)
HALF LEAD
OPTION
8
7
6
5
0.025
(0.635)
RAD TYP
0.045 – 0.068
(1.143 – 1.727)
FULL LEAD
OPTION
0.220 – 0.310
(5.588 – 7.874)
1
2
3
0.300 BSC
(0.762 BSC)
4
0.200
(5.080)
MAX
0.015 – 0.060
(0.381 – 1.524)
0.008 – 0.018
(0.203 – 0.457)
0° – 15°
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
0.045 – 0.065
(1.143 – 1.651)
0.014 – 0.026
(0.360 – 0.660)
0.125
3.175
MIN
0.100
(2.54)
BSC
J8 1298
OBSOLETE PACKAGE
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
0.300 – 0.325
(7.620 – 8.255)
0.045 – 0.065
(1.143 – 1.651)
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
(
0.400*
(10.160)
MAX
0.130 ± 0.005
(3.302 ± 0.127)
+0.035
0.325 –0.015
+0.889
8.255
–0.381
)
8
7
6
5
1
2
3
4
0.255 ± 0.015*
(6.477 ± 0.381)
0.100
(2.54)
BSC
0.125
(3.175) 0.020
MIN (0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
N8 1098
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.053 – 0.069
(1.346 – 1.752)
0.008 – 0.010
(0.203 – 0.254)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
8
7
6
5
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
2
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.
3
4
SO8 1298
15
LT1011/LT1011A
U
TYPICAL APPLICATION
10Hz to 100kHz Voltage to Frequency Converter
R7
4.7k
R4
1M
15V
15V
C1
0.002µF
POLYSTYRENE
R1
4.7k
LT1009
2.5V
15V
INPUT
0V TO 10V
R2
5k
FULL-SCALE
R3
TRIM
8.06k
3
C2
0.68µF
15V
R16
50k
10Hz TRIM
R5
2k
15V
R8
4.7k
7
1
+
R17†
22M
LINEARITY ≈ 0.01%
8
–
LT1011
2
R6
2k
–15V
4
1.5µs
6
4.4V
–15V
0.002µF
15V
– 15V
15V
–15V
R9
5k
Q2
ALL DIODES 1N4148
TRANSISTORS 2N3904
*USED ONLY TO GUARANTEE
START-UP
†
MAY BE INCREASED FOR BETTER
10Hz TRIM RESOLUTION
R15
22k
Q1*
TTL OUTPUT
10HZ TO 100kHz
R11
20k
10pF
R14
1k
1.5µs
R10
2.7k
R12
100k
1011 TA22
+
2µF
R13
620k
–15V
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1016
UltraFastTM Precision Comparator
Industry Standard 10ns Comparator
LT1116
12ns Single Supply Ground-Sensing Comparator
Single Supply Version of the LT1016
LT1394
UltraFast Single Supply Comparator
7ns, 6mA Single Supply Comparator
LT1671
60ns, Low Power Comparator
450µA Single Supply Comparator
UltraFast is a trademark of Linear Technology Corporation.
16
Linear Technology Corporation
sn1011 1011fbs LT/CP 0901 1.5K REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 1991
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