ETC LT1639HS

LT1638/LT1639
1.2MHz, 0.4V/µs
Over-The-TopTM Micropower
Rail-to-Rail Input and Output
Op Amps
DESCRIPTIO
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FEATURES
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Operates with Inputs Above V +
Rail-to-Rail Input and Output
Low Power: 230µA per Amplifier Max
Gain Bandwidth Product: 1.2MHz
Slew Rate: 0.4V/µs
High Output Current: 25mA Min
Specified on 3V, 5V and ±15V Supplies
Reverse Battery Protection to 18V
No Supply Sequencing Problems
High Voltage Gain: 1500V/mV
Single Supply Input Range: – 0.4V to 44V
High CMRR: 98dB
No Phase Reversal
The LT ®1638 is a low power dual rail-to-rail input and output
operational amplifier available in the standard 8-pin PDIP and
SO packages as well as the 8-lead MSOP package. The
LT1639 is a low power quad rail-to-rail input and output
operational amplifier offered in the standard 14-pin PDIP and
surface mount packages.
The LT1638/LT1639 op amps operate on all single and
split supplies with a total voltage of 2.5V to 44V drawing
only 170µA of quiescent current per amplifier. These
amplifiers are reverse battery protected and draw no
current for reverse supply up to 18V.
The input range of the LT1638/LT1639 includes both
supplies, and a unique feature of this device is its capability
to operate over the top with either or both of its inputs
above V +. The inputs handle 44V, both differential and
common mode, independent of supply voltage. The input
stage incorporates phase reversal protection to prevent
false outputs from occurring even when the inputs are 22V
below the negative supply. Protective resistors are
included in the input leads so that current does not
become excessive when the inputs are forced below the
negative supply. The LT1638/LT1639 can drive loads up to
25mA and still maintain rail-to-rail capability. The op amps
are unity-gain stable and drive all capacitive loads up to
1000pF when optional output compensation is used.
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APPLICATIO S
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Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
Supply Current Sensing
Battery Monitoring
Micropower Active Filters
4mA to 20mA Transmitters
, LTC and LT are registered trademarks of Linear Technology Corporation.
Over-The-Top is a trademark of Linear Technology Corporation.
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TYPICAL APPLICATIO
Output Voltage vs Input Voltage
Over-The-Top Comparator with 100mV Hysteresis Centered at 0mV
10k
1M
5V
VCC
V1
VCC
VCC
1M
+
+
A
1/2 LT1638
B
1/2 LT1638
–
1M
V0
–
0V
10k
1M
1638/39 TA01
V2
VCC = 5V, VCM = 0V TO 44V, tPD = 27µs
20mV/DIV
1638/39 TA02
1
LT1638/LT1639
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W W
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ABSOLUTE MAXIMUM RATINGS
(Note 1)
Total Supply Voltage (V + to V –) .............................. 44V
Input Differential Voltage ......................................... 44V
Input Current ...................................................... ±25mA
Output Short-Circuit Duration (Note 2) .........Continuous
Operating Temperature Range (Note 3)
LT1638C/LT1639C ............................. – 40°C to 85°C
LT1638I/LT1639I ................................ – 40°C to 85°C
LT1638H/LT1639H ........................... – 40°C to 125°C
Specified Temperature Range (Note 4)
LT1638C/LT1639C ............................. – 40°C to 85°C
LT1638I/LT1639I ................................ – 40°C to 85°C
LT1638H/LT1639H ........................... – 40°C to 125°C
Junction Temperature ........................................... 150°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
W
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PACKAGE/ORDER INFORMATION
TOP VIEW
TOP VIEW
OUT A
–IN A
+IN A
V–
1
2
3
4
8
7
6
5
V+
OUT B
–IN B
+IN B
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 300°C/ W (MS8)
ORDER PART NUMBER
LT1638CMS8
MS8 PART MARKING
LTCY
TOP VIEW
OUT A
1
8
V+
OUT A
1
–IN A
2
7
OUT B
–IN A
2
+IN A
3
6
–IN B
+IN A
3
+IN B
V+
4
+IN B
5
A
B
V–
4
5
S8 PACKAGE
N8 PACKAGE
8-LEAD PDIP 8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 150°C/ W (N8)
TJMAX = 150°C, θJA = 190°C/ W (S8)
OUT B
7
13 –IN D
D
12 +IN D
11 V –
10 +IN C
B
C
9
– IN C
8
OUT C
S PACKAGE
14-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 130°C/ W (N)
TJMAX = 150°C, θJA = 160°C/ W (S)
LT1638CS8
LT1638IS8
LT1638HS8
ORDER PART NUMBER
S8 PART MARKING
1638
6
A
N PACKAGE
14-LEAD PDIP
ORDER PART NUMBER
LT1638CN8
LT1638IN8
–IN B
14 OUT D
LT1639CN
LT1639IN
1638I
1638H
LT1639CS
LT1639IS
LT1639HS
Consult factory for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C.
VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted. (Note 4)
SYMBOL
VOS
PARAMETER
Input Offset Voltage
Input Offset Voltage Drift
(Note 9)
2
CONDITIONS
LT1638 N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1639 N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1638C MS8 Package
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1638/LT1639 N, S Packages
LT1638CMS8
●
●
●
●
LT1638C/LT1639C, LT1638I/LT1639I
MIN
TYP
MAX
200
600
850
950
300
700
950
1050
350
●
●
●
●
2
2.5
900
1150
1250
6
7
UNITS
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV/°C
µV/°C
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C.
VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted. (Note 4)
SYMBOL
IOS
PARAMETER
Input Offset Current
VCM = 44V (Note 5)
IB
Input Bias Current
VCM = 44V (Note 5)
VS = 0V
en
Input Noise Voltage
Input Noise Voltage Density
0.1Hz to 10Hz
f = 1kHz
in
RIN
Input Noise Current Density
Input Resistance
f = 1kHz
Differential
Common Mode, VCM = 0V to 44V
CIN
Input Capacitance
CMRR
Input Voltage Range
Common Mode Rejection Ratio
AVOL
Large-Signal Voltage Gain
VOL
VOH
Output Voltage Swing Low
Output Voltage Swing High
ISC
Short-Circuit Current (Note 2)
PSRR
Power Supply Rejection Ratio
Reverse Supply Voltage
Minimum Operating Supply Voltage
IS
GBW
SR
Slew Rate
(Note 7)
UNITS
nA
µA
nA
µA
nA
1
20
µVP-P
nV/√Hz
1
1.4
0.3
2.5
5.5
5
pA/√Hz
MΩ
MΩ
pF
98
88
1500
●
●
0
88
80
200
133
100
●
●
400
250
200
●
●
●
●
●
VCM = 0V to VCC – 1V
VCM = 0V to 44V (Note 8)
VS = 3V, VO = 500mV to 2.5V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
VS = 5V, VO = 500mV to 4.5V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
VS = 3V, No Load
VS = 3V, ISINK = 5mA
VS = 5V, No Load
VS = 5V, ISINK = 10mA
VS = 3V, No Load
VS = 3V, ISOURCE = 5mA
VS = 5V, No Load
VS = 5V, ISOURCE = 10mA
VS = 3V, Short to GND
VS = 3V, Short to VCC
VS = 5V, Short to GND
VS = 5V, Short to VCC
VS = 3V to 12.5V, VCM = VO = 1V
IS = – 100µA per Amplifier
●
●
●
●
●
●
●
2.94
2.25
4.94
3.8
10
15
15
15
90
●
18
●
●
●
●
●
Supply Current per Amplifier
(Note 6)
Gain Bandwidth Product
(Note 5)
LT1638C/LT1639C, LT1638I/LT1639I
MIN
TYP
MAX
1
6
2.5
20
50
8
30
0.1
CONDITIONS
44
1500
3
250
3
500
2.98
2.40
4.98
4.0
15
25
20
25
100
27
2.4
170
●
f = 5kHz
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
AV = – 1, RL = ∞
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
●
●
●
●
650
550
500
0.210
0.185
0.170
1075
0.38
8
450
8
700
V
dB
dB
V/mV
V/mV
V/mV
V/mV
V/mV
V/mV
mV
mV
mV
mV
V
V
V
V
mA
mA
mA
mA
dB
2.7
V
V
230
275
µA
µA
kHz
kHz
kHz
V/µs
V/µs
V/µs
3
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C.
VS = ±15V, VCM = 0V, VOUT = 0V, unless otherwise noted. (Note 4)
LT1638C/LT1639C, LT1638I/LT1639I
SYMBOL
VOS
IOS
PARAMETER
Input Offset Voltage
Input Offset Voltage Drift
(Note 9)
Input Offset Current
CONDITIONS
LT1638 N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1639 N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1638C MS8 Package
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1638/LT1639 N, S Packages
LT1638CMS8
MIN
TYP
250
●
●
350
●
●
400
●
●
2
2.5
1
●
●
●
MAX
800
1000
1100
900
1100
1200
UNITS
µV
µV
µV
µV
µV
µV
1050
1250
1350
6
7
6
µV
µV
µV
µV/°C
µV/°C
nA
IB
Input Bias Current
Input Noise Voltage
0.1Hz to 10Hz
20
1
en
in
Input Noise Voltage Density
Input Noise Current Density
f = 1kHz
f = 1kHz
20
0.3
nV/√Hz
pA/√Hz
RIN
Input Resistance
Differential
Common Mode, VCM = – 15V to 14V
2.5
500
MΩ
MΩ
CIN
CMRR
Input Capacitance
Input Voltage Range
Common Mode Rejection Ratio
AVOL
Large-Signal Voltage Gain
VO
Output Voltage Swing
ISC
Short-Circuit Current (Note 2)
PSRR
Power Supply Rejection Ratio
IS
Supply Current per Amplifier
GBW
Gain Bandwidth Product
●
1
VCM = –15V to 29V
VO = ±14V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
No Load
IOUT = ±10mA
●
– 15
80
●
●
200
125
100
±14.9
±13.7
Short to GND
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
●
●
25
20
15
VS = ±1.5V to ±22V
●
90
●
●
29
88
500
4
Slew Rate
pF
V
dB
V/mV
V/mV
V/mV
V
V
±14.95
±14.0
40
mA
mA
mA
100
205
nA
µVP-P
4.5
●
●
SR
50
dB
280
350
µA
µA
f = 5kHz
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
750
650
600
1200
●
●
kHz
kHz
kHz
AV = – 1, RL = ∞, VO = ±10V,
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
0.225
0.2
0.18
0.4
●
●
V/µs
V/µs
V/µs
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA ≤ 125°C.
VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = Half Supply unless otherwise specified. (Note 4)
SYMBOL
VOS
PARAMETER
Input Offset Voltage
CONDITIONS
LT1638S8
●
LT1638H/LT1639H
MIN
TYP
MAX
200
650
3
LT1639S
300
●
IOS
Input Offset Voltage Drift (Note 9)
Input Offset Current
IB
Input Bias Current
●
VCM = 44V (Note 5)
●
●
VCM = 44V (Note 5)
●
●
Input Voltage Range
CMRR
Common Mode Rejection Ratio
VCM = 0.3V to VCC – 1V
VCM = 0.3V to 44V
AVOL
Large-Signal Voltage Gain
VS = 3V, VO = 500mV to 2.5V, RL = 10k
Output Voltage Swing Low
VOH
Output Voltage Swing High
PSRR
Power Supply Rejection Ratio
Minimum Supply Voltage
Reverse Supply Voltage
IS
GBW
SR
No Load
ISINK = 5mA
VS = 5V, ISINK = 10mA
VS = 3V, No Load
VS = 3V, ISOURCE = 5mA
VS = 5V, No Load
VS = 5V, ISOURCE = 10mA
VS = 3V to 12.5V, VCM = VO = 1V
IS = – 100µA
Slew Rate
(Note 7)
AV = – 1, RL = ∞
µV/°C
nA
µA
nA
µA
V
76
72
200
20
1500
●
V/mV
V/mV
400
35
1500
●
V/mV
V/mV
dB
dB
15
900
1500
●
●
●
●
●
●
●
●
●
mV
mV
mV
2.9
2
4.9
3.5
80
V
V
V
V
dB
2.7
18
V
V
170
f = 5kHz
15
15
10
150
100
44
0.3
●
Gain Bandwidth Product
(Note 5)
µV
mV
●
●
●
Supply Current
(Note 6)
750
3.2
●
VS = 5V, VO = 500mV to 4.5V, RL = 10k
VOL
UNITS
µV
mV
230
450
µA
µA
650
350
1075
●
kHz
kHz
0.21
0.1
0.38
●
V/µs
V/µs
5
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA␣ ≤␣ 125°C, otherwise
specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V – unless otherwise specified. (Note 4)
SYMBOL
VOS
PARAMETER
Input Offset Voltage
CONDITIONS
LT1638S8
●
LT1638H/LT1639H
MIN
TYP
MAX
250
850
3.4
LT1639S
350
●
IOS
Input Offset Voltage Drift (Note 9)
Input Offset Current
IB
CMRR
Input Bias Current
Common Mode Rejection Ratio
VCM = –14.7V to 29V
AVOL
Large-Signal Voltage Gain
VO = ±14V, RL = 10k
VO
Output Voltage Swing
PSRR
Power Supply Rejection Ratio
IS
Minimum Supply Voltage
Supply Current
●
●
●
No Load
IOUT = ± 5mA
IOUT = ±10mA
VS = ±1.5V to ±22V
●
72
●
200
15
●
±14.8
±14
±13.4
84
●
±1.35
●
●
●
Gain Bandwidth Product
●
SR
Slew Rate
AV = – 1, RL = ∞, VO = ±10V,
Measure at VO = ±5V
Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
Note 2: A heat sink may be required to keep the junction temperature
below absolute maximum. This depends on the power supply voltage
and how many amplifiers are shorted.
Note 3: The LT1638C/LT1639C and LT1638I/LT1639I are guaranteed
functional over the operating temperature range of –40°C to 85°C. The
LT1638H/LT1639H are guaranteed functional over the operating
temperature range of – 40°C to 125°C.
Note 4: The LT1638C/LT1639C are guaranteed to meet specified
performance from 0°C to 70°C and are designed, characterized and
expected to meet specified performance from –40°C to 85°C but not
tested or QA sampled at these temperatures. The LT1638I/LT1639I are
6
●
750
400
0.225
0.1
µV
mV
15
25
µV/°C
nA
250
nA
dB
V/mV
V/mV
V
V
V
dB
205
f = 5kHz
950
3.6
500
●
GBW
UNITS
µV
mV
1200
0.4
280
550
V
µA
µA
kHz
kHz
V/µs
V/µs
guaranteed to meet specified performance from –40°C to 85°C. The
LT1638H/LT1639H are guaranteed to meet specified performance from
–40°C to 125°C.
Note 5: VS = 5V limits are guaranteed by correlation to VS = 3V and
VS = ±15V or VS = ±22V tests.
Note 6: VS = 3V limits are guaranteed by correlation to VS = 5V and
VS = ±15V or VS = ±22V tests.
Note 7: Guaranteed by correlation to slew rate at VS = ±15V, and GBW at
VS = 3V and VS = ±15V tests.
Note 8: This specification implies a typical input offset voltage of 2mV at
VCM = 44V and a maximum input offset voltage of 5mV at VCM = 44V.
Note 9: This parameter is not 100% tested.
LT1638/LT1639
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TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Supply Voltage
260
TA = 125°C
240
220
TA = 25°C
200
180
TA = –55°C
160
140
120
400
10000
300
8000
200
100
0
5
0
10
15 20 25 30 35
SUPPLY VOLTAGE (V)
40
TA = 25°C
–100
TA = 125°C
TA = –55°C
–200
–300
– 400
100
INPUT BIAS CURRENT (nA)
CHANGE IN INPUT OFFSET VOLTAGE (µV)
SUPPLY CURRENT PER AMPLIFIER (µA)
300
280
Input Bias Current vs
Common Mode Voltage
Minimum Supply Voltage
45
0
1
3
4
2
TOTAL SUPPLY VOLTAGE (V)
TA = –55°C
0.01
0.1
1
SOURCING LOAD CURRENT (mA)
10
TA = 125°C
TA = 25°C
0.01
TA = –55°C
0.001
0.001
0.01
0.1
1
SINKING LOAD CURRENT (mA)
7
8
10
OUTPUT LOW
9
10
1638/39 G07
0 10 20 30 40 50 60 70 80 90 100
INPUT OVERDRIVE (mV)
1638/39 G05
1638/39 G06
Input Noise Current Density
vs Frequency
4.5
INPUT NOISE CURRENT DENSITY (pA/√Hz)
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
4 5 6
TIME (SEC)
OUTPUT HIGH
1
10
70
3
44
VS = ±2.5V
NO LOAD
Noise Voltage Density vs
Frequency
VS = ±2.5
4.4
5.2
5.6
4.8
COMMON MODE VOLTAGE (V)
100
0.1
0.1Hz to 10Hz Noise Voltage
2
TA = 25°C
Output Saturation Voltage vs
Input Overdrive
VS = ±2.5V
VOD = 30mV
1638/39 G04
1
TA = 125°C
0
1638/39 G03
OUTPUT SATURATION VOLTAGE (mV)
OUTPUT SATURATION VOLTAGE (V)
TA = 25°C
0
20
–40
4.0
5
1
NOISE VOLTAGE (400nV/DIV)
OUTPUT SATURATION VOLTAGE (V)
1
0.01
0.001
40
Output Saturation Voltage vs
Load Current (Output Low)
TA = 125°C
TA = –55°C
60
1638/39 G02
Output Saturation Voltage vs
Load Current (Output High)
0.1
6000
–20
1638/39 G01
VS = ±2.5V
VOD = 30mV
VS = 5V, 0V
60
50
40
30
20
10
0
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
1
10
100
FREQUENCY (Hz)
1k
1638/39 G09
1
10
100
FREQUENCY (Hz)
1k
1638/39 G08
7
LT1638/LT1639
U W
TYPICAL PERFORMANCE CHARACTERISTICS
Gain and Phase Shift vs
Frequency
Gain Bandwith Product vs
Temperature
100
80
PHASE
50
70
40
60
50
GAIN
20
40
10
30
0
20
10
–10
0
1000
–20
10
100
FREQUENCY (kHz)
1
1400
0.55
1300
VS = ±15V
1200
1100
1000
VS = ±2.5V
900
800
–50 –25
50
0
75
25
TEMPERATURE (°C)
1638/39 G12
50
1300
40
GAIN BANDWIDTH
30
1100
20
0
5
10 15 20 25 30 35 40
TOTAL SUPPLY VOLTAGE (V)
VS = ± 2.5V
AV = –1
RF = RG = 100k
f = 1kHz
1400
1300
50
25
0
75
TEMPERATURE (°C)
1100
20
GAIN BANDWIDTH
PRODUCT
1000
90
50
30
10
900
0
800
–10
100
1
10
LOAD RESISTANCE (kΩ)
VS = ±15V
125
70
60
POSITIVE SUPPLY
50
40
30
NEGATIVE SUPPLY
20
10
0
–10
1
10
100
FREQUENCY (kHz)
1000
1638/39 G16
Output Impedance vs Frequency
Channel Separation vs Frequency
130
100
VS = ±2.5V
80
1638/39 G17
10k
VS = ±15V
VS = ± 2.5V
90
80
70
60
50
40
OUTPUT IMPEDANCE (Ω)
120
CHANNEL SEPARATION (dB)
COMMON MODE REJECTION RATIO (dB)
FALLING, VS = ±15V
PSRR vs Frequency
1200
10
45
100
110
100
90
80
1k
100
AV = 10
AV = 100
10
AV = 1
1
70
30
20
1
10
100
FREQUENCY (kHz)
1000
1638/39 G18
8
FALLING, VS = ±2.5V
0.35
1638/39 G14
60
PHASE MARGIN
CMRR vs Frequency
110
0.40
0.25
–50 –25
125
40
1638/39 G15
120
100
PHASE MARGIN (DEG)
PHASE MARGIN
GAIN BANDWIDTH PRODUCT (kHz)
1500
PHASE MARGIN (DEG)
GAIN BANDWIDTH PRODUCT (kHz)
1400
1000
RISING, VS = ±2.5V
0.45
Gain Bandwidth Product and
Phase Margin vs Load Resistance
60
1200
0.50
1638/39 G13
Gain Bandwidth Product and
Phase Margin vs Supply Voltage
1500
RISING, VS = ±15V
0.30
POWER SUPPLY REJECTION RATIO (dB)
30
PHASE SHIFT (DEG)
GAIN (dB)
f = 1kHz
90
60
0.60
SLEW RATE (V/µs)
VS = ±2.5V
70
Slew Rate vs Temperature
1500
GAIN BANDWIDTH PRODUCT (kHz)
80
60
0.1
1
10
FREQUENCY (kHz)
100
1638/39 G19
0.1
0.1
1
10
100
FREQUENCY (kHz)
1000
1638/39 G20
LT1638/LT1639
U W
TYPICAL PERFORMANCE CHARACTERISTICS
Settling Time to 0.1% vs
Output Step
100
VS = ±15V
8
80
AV = –1
4
OVERSHOOT (%)
2
0
–2
–4
AV = –1
–6
60
AV = 5
AV = 1
40
30
AV = 10
5
20
15
10
25
SETTLING TIME (µs)
35
30
10
100
1000
CAPACITIVE LOAD (pF)
Total Harmonic Distortion + Noise
vs Frequency
THD + NOISE (%)
VS = ±1.5V
VIN = ±1V
0.1
VS = 3V, 0V
VIN = 0.5V TO 2.5V
0.01
100
0.001
0.1
Open-Loop Gain
0.001
1
10
LOAD RESISTANCE TO GROUND (kΩ)
1638/39 G24
0.1
0.01
VS = 3V, 0V
VIN = 0.2V TO 2.2V
1
10
FREQUENCY (Hz)
RL = 10k, f = 1kHz
VCM = HALF SUPPLY
AV = –1, VS = ±1.5V
AV = –1, VS = 3V, 0V
AV = 1, VS = ±1.5V
AV = 1, VS = 3V, 0V
1
AV = 1
0.1
100
10
1
AV = –1
1
10
FREQUENCY (kHz)
Total Harmonic Distortion + Noise
vs Output Voltage
VS = 3V TOTAL
AV = 1
VIN = 2VP-P AT 1kHz
0.1
0.001
0.01
VS = ± 2.5V
1638/39 G23
10
VS = 3V, 0V
VOUT = 2VP-P
VCM = 1.2V
RL = 20k
CHANGE IN INPUT OFFSET VOLTAGE (50µV/DIV)
THD + NOISE (%)
10000
Total Harmonic Distortion + Noise
vs Load Resistance
10
0.01
10
1638/39 G22
1638/39 G21
1
15
0
0.1
0
–10
0
20
5
10
DISTORTION ≤ 1%
RL = 20k
25
20
AV = 1
–8
70
50
VS = ±15V
30
THD + NOISE (%)
OUTPUT STEP (V)
90
AV = 1
6
35
VS = 5V, 0V
VCM = 2.5V
ISOURCE = 150µA
OUTPUT SWING (VP-P)
10
Undistorted Output Swing
vs Frequency
Capacitive Load Handling,
Overshoot vs Capacitive Load
100
0
2
1
OUTPUT VOLTAGE (VP-P)
1638/39 G26
1638/39 G25
Large-Signal Response
3
Small-Signal Response
VS = ±15V
RL = 2k
RL = 10k
RL = 50k
VS = ±15V
AV = 1
–20V
–10V
10V
0V
OUTPUT VOLTAGE (5V/DIV)
1638/39 G28
VS = ±15V
AV = 1
CL = 15pF
1638/39 G29
20V
1638/39 G27
9
LT1638/LT1639
U
W
U
U
APPLICATIONS INFORMATION
Supply Voltage
The positive supply pin of the LT1638/LT1639 should be
bypassed with a small capacitor (typically 0.1µF) within an
inch of the pin. When driving heavy loads an additional
4.7µF electrolytic capacitor should be used. When using
split supplies, the same is true for the negative supply pin.
The LT1638/LT1639 are protected against reverse battery
voltages up to 18V. In the event a reverse battery condition
occurs, the supply current is less than 1nA.
The LT1638/LT1639 can be shut down by removing V +. In
this condition the input bias current is less than 0.1nA,
even if the inputs are 44V above the negative supply.
At temperatures greater than 70°C, when operating the
LT1638/LT1639 on total supplies of 10V or more, the
supply must not be brought up faster than 1V/µs. Increasing the bypass capacitor and/or adding a small resistor in
series with the supply will limit the rise time.
Inputs
The LT1638/LT1639 have two input stages, NPN and PNP
(see the Simplified Schematic), resulting in three distinct
operating regions as shown in the Input Bias Current vs
Common Mode typical performance curve.
For input voltages about 0.8V or more below V +, the PNP
input stage is active and the input bias current is typically
– 20nA. When the input common mode voltage is within
0.5V of the positive rail, the NPN stage is operating and the
input bias current is typically 40nA. Increases in temperature will cause the voltage at which operation switches
from the PNP input stage to the NPN input stage to move
towards V +. The input offset voltage of the NPN stage is
untrimmed and is typically 600µV.
A Schottky diode in the collector of each NPN transistor
allow the LT1638/LT1639 to operate over the top, with
either or both of its inputs above V +. At about 0.3V above
V + the NPN input transistor is fully saturated and the input
bias current is typically 8µA at room temperature. The
input offset voltage is typically 2mV when operating above
V +. The LT1638/LT1639 will operate with its inputs 44V
above V – regardless of V +.
10
The inputs are protected against excursions as much as
22V below V – by an internal 1k resistor in series with each
input and a diode from the input to the negative supply.
The input stage of the LT1638/LT1639 incorporates phase
reversal protection to prevent the output from phase
reversing for inputs up to 22V below V –. There are no
clamping diodes between the inputs and the maximum
differential input voltage is 44V.
Output
The output of the LT1638/LT1639 can swing within 20mV
of the positive rail with no load, and within 3mV of the
negative rail with no load. When monitoring voltages
within 20mV of the positive rail or within 3mV of the
negative rail, gain should be taken to keep the output from
clipping. The LT1638/LT1639 are capable of sinking and
sourcing over 40mA on ±15V supplies; sourcing current
capability is reduced to 20mA at 5V total supplies as noted
in the electrical characteristics.
The LT1638/LT1639 are internally compensated to drive
at least 200pF of capacitance under any output loading
conditions. A 0.22µF capacitor in series with a 150Ω
resistor between the output and ground will compensate
these amplifiers for larger capacitive loads, up to 1000pF,
at all output currents.
Optional Output Compensation for
Capacitive Loads Greater than 200pF
VIN
+
LT1638
–
1000pF
0.22µF
150Ω
Distortion
There are two main contributors of distortion in op amps:
output crossover distortion as the output transitions from
sourcing to sinking current and distortion caused by
LT1638/LT1639
U
W
U
U
APPLICATIONS INFORMATION
nonlinear common mode rejection. If the op amp is operating inverting there is no common mode induced distortion. If the op amp is operating in the PNP input stage
(input is not within 0.8V of V +), the CMRR is very good,
typically 98dB. When the LT1638 switches between input
stages there is significant nonlinearity in the CMRR. Lower
load resistance increases the output crossover distortion,
but has no effect on the input stage transition distortion.
For lowest distortion the LT1638/LT1639 should be operated single supply, with the output always sourcing
current and with the input voltage swing between ground
and (V + – 0.8V). See the Typical Performance Characteristics curves.
Gain
The open-loop gain is almost independent of load when
the output is sourcing current. This optimizes performance in single supply applications where the load is
returned to ground. The typical performance curve of
Open-Loop Gain for various loads shows the details.
U
TYPICAL APPLICATIONS
VCC
R5
100k
With 1.2MHz bandwidth, Over-The-Top capability, reverse-battery protection and rail-to-rail input and output
features, the LT1638/LT1639 are ideal candidates for
general purpose applications.
The lowpass slope limiting filter in Figure 1 limits the
maximum dV/dT (not frequency) that it passes. When the
input signal differs from the output by one forward diode
drop, D1 or D2 will turn on. With a diode on, the voltage
across R2 will be constant and a fixed current, VDIODE/R2,
will flow through capacitor C1, charging it linearly instead
of exponentially. The maximum slope that the circuit will
pass is equal to VDIODE divided by (R2)(C1). No matter
how fast the input changes the output will never change
any faster than the dV/dT set by the diodes and (R2)(C).
+
1/4 LT1639
D1 R3
100k
–
R1
1k
D2
VOUT
1/4 LT1639
R2
+
VIN
C1
R4
100k
D3
LT1634-1.2V
D4
–
1/4 LT1639
FOR R2 = 50k, C1 = 500pF,
MAXIMUM SLOPE = 0.048V/µs
1.2V
d
=
V
dt OUT (R2)(C1)
D1
LT1634-1.2V
–
D2
+
R6
100k
1638/39 F02
D1 TO D4 = IN4148
R1
VIN
VD
d
V
=
dt OUT(MAX) (R2)(C1)
FOR R1 = 10k, R2 = 100k, C1 = 1000pF
d
V
= 0.006V/µs
dt OUT(MAX)
R2
VEE
+
C1 1/2 LT1638
Response of Slope Limiting Filter
VOUT
–
1638/39 F01
VOUT
Figure 1. Lowpass Slope Limiting Filter
A modification of this application is shown in Figure 2
using references instead of diodes to set the maximum
slope. By using references, the slope is independent of
temperature. A scope photo shows a 1VP-P, 2kHz input
signal with a 2V pulse added to the sine wave; the circuit
passes the 2kHz signal but limits the slope of the pulse.
VIN
1638/39 TA02
Figure 2. Lowpass Slope Limiting Filter with 0 TC
11
LT1638/LT1639
U
TYPICAL APPLICATIONS
The Figure 4 application uses the LT1638 in conjunction
with the LT1634 micropower shunt reference. The supply
current of the op amp also biases the reference. The drop
across resistor R1 is fixed at 1.2V generating an output
current equal to 1.2V/R1.
The application in Figure 3 utilizes the Over-The-Top
capabilities of the LT1638. The 0.2Ω resistor senses the
load current while the op amp and NPN transistor form a
closed loop making the collector current of Q1
proportional to the load current. As a convenient monitor,
the 2k load resistor converts the current into a voltage. The
positive supply rail, V +, is not limited to the 5V supply of
the op amp and could be as high as 44V.
V+
200Ω
VCC
+
Q1
2N3904
1/2 LT1638
200Ω
LOAD
R1
LT1634-1.2
5V
0.2Ω
VCC
–
+
0V TO 4.3V
IOUT = 1.2V
R1
1/2 LT1638
2k
ILOAD
–
IOUT
1638/39 F03
VOUT = (2Ω)(ILOAD)
1638/39 F04
Figure 3. Positive Supply Rail Current Sense
Figure 4. Current Source
W
W
SI PLIFIED SCHE ATIC
V+
Q2
Q1
D1
R1
6k
Q3
D2
Q22
D3
R2
1k
Q4
Q19
– IN
Q17
Q7
R3
1k
+
10µA
Q11
OUT
+IN
Q6
Q20
Q12
Q16
Q18
Q15
Q9
Q5
Q8
D4
D5
Q10
Q13
Q14
R4
8k
Q21
R5
8k
V–
ONE AMPLIFIER
12
1638/39 SS
LT1638/LT1639
U
PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package
8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.043
(1.10)
MAX
0.007
(0.18)
0.118 ± 0.004*
(3.00 ± 0.102)
0.034
(0.86)
REF
8
7 6
5
0° – 6° TYP
SEATING
PLANE
0.021 ± 0.006
(0.53 ± 0.015)
0.009 – 0.015
(0.22 – 0.38)
0.0256
(0.65)
BSC
0.005 ± 0.002
(0.13 ± 0.05)
0.118 ± 0.004**
(3.00 ± 0.102)
0.193 ± 0.006
(4.90 ± 0.15)
1
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,
PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
2 3
4
MSOP (MS8) 1100
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.300 – 0.325
(7.620 – 8.255)
0.009 – 0.015
(0.229 – 0.381)
(
+0.035
0.325 –0.015
+0.889
8.255
–0.381
)
0.045 – 0.065
(1.143 – 1.651)
0.065
(1.651)
TYP
0.100 ± 0.010
(2.540 ± 0.254)
0.400*
(10.160)
MAX
0.130 ± 0.005
(3.302 ± 0.127)
8
7
6
5
1
2
3
4
0.255 ± 0.015*
(6.477 ± 0.381)
0.125
(3.175) 0.020
MIN (0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
N8 1197
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
13
LT1638/LT1639
U
PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(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)
7
8
0.004 – 0.010
(0.101 – 0.254)
5
6
0°– 8° TYP
0.016 – 0.050
0.406 – 1.270
0.014 – 0.019
(0.355 – 0.483)
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
0.050
(1.270)
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
SO8 0996
1
3
2
4
N Package
14-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.325
(7.620 – 8.255)
0.045 – 0.065
(1.143 – 1.651)
0.020
(0.508)
MIN
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
+0.035
0.325 –0.015
(
+0.889
8.255
–0.381
14
)
0.770*
(19.558)
MAX
0.125
(3.175)
MIN
0.005
(0.125)
MIN
0.100 ± 0.010
(2.540 ± 0.254)
0.018 ± 0.003
(0.457 ± 0.076)
14
13
12
11
10
9
8
1
2
3
4
5
6
7
0.255 ± 0.015*
(6.477 ± 0.381)
N14 1197
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
LT1638/LT1639
U
PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted.
S Package
14-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.337 – 0.344*
(8.560 – 8.738)
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
14
13
12
11
10
9
8
0° – 8° TYP
0.050
0.016 – 0.050
(1.270)
0.406 – 1.270
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
0.014 – 0.019
(0.355 – 0.483)
0.228 – 0.244
(5.791 – 6.197)
0.150 – 0.157**
(3.810 – 3.988)
S14 0695
1
2
3
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.
4
5
6
7
15
LT1638/LT1639
U
TYPICAL APPLICATION
The battery monitor in Figure 5 also demonstrates the
LT1638’s ability to operate with its inputs above the
positive rail. In this application, a conventional amplifier
would be limited to a battery voltage between 5V and
ground, but the LT1638 can handle battery voltages as
high as 44V. When the battery is charging, Amp B senses
the voltage drop across RS. The output of Amp B causes
Q2 to drain sufficient current through RB to balance the
input of Amp B. Likewise, Amp A and Q1 form a closed
RS, 0.2Ω
CHARGER
VOLTAGE
RA, 2k
RA', 2k
IBATT
loop when the battery is discharging. The current through
Q1 or Q2 is proportional to the current in RS and this
current flows into RG and is converted into a voltage. Amp
D buffers and amplifies the voltage across RG. Amp C
compares the output of Amp A and Amp B to determine
the polarity of current through RS. The scale factor for
VOUT with S1 open is 1V/A. With S1 closed the scale factor
is 1V/100mA and currents as low as 500µA can be
measured.
Q1
2N3904
+
A
1/4 LT1639
+
C
1/4 LT1639
–
LOGIC
–
RB, 2k
RB', 2k
LOAD
+
+
Q2
2N3904
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
B
1/4 LT1639
+
–
RG
10k
VBATT = 12V
D
1/4 LT1639
VOUT
–
S1
10k
90.9k
1638/39 F05
IBATT =
VOUT
V
= OUT AMPS
(RS)(RG /RA)(GAIN) GAIN
S1 = OPEN, GAIN = 1
S1 = CLOSED, GAIN = 10
RA = RB
VS = 5V, 0V
Figure 5. Battery Monitor
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1078/LT1079
LT2078/LT2079
Dual/Quad 55µA Max, Single Supply, Precision Op Amps
Input/Output Common Mode Includes Ground, 70µV VOS(MAX)
and 2.5µV/°C Drift (Max), 200kHz GBW, 0.07V/µs Slew Rate
LT1178/LT1179
LT2178/LT2179
Dual/Quad 17µA Max, Single Supply, Precison Op Amps
Input/Output Common Mode Includes Ground, 70µV VOS(MAX)
and 4µV/°C Drift (Max), 85kHz GBW, 0.04V/µs Slew Rate
LT1366/LT1367
Dual/Quad Precision, Rail-to-Rail Input and Output Op Amps
475µV VOS(MAX), 500V/mV AVOL(MIN), 400kHz GBW
LT1490/LT1491
Dual/Quad Over-The-Top Micropower, Rail-to-Rail Input and
Output Op Amps
Single Supply Input Range: – 0.4V to 44V, Micropower 50µA
per Amplifier, Rail-to-Rail Input and Output, 200kHz GBW
LT1636
Single Over-The-Top Micropower Rail-to-Rail Input and Output
Op Amp
55µA Supply Current, VCM Extends 44V above VEE,
Independent of VCC; MSOP Package, Shutdown Function
16
Linear Technology Corporation
16389fa LT/TP 0201 2K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1998