ANALOG DEVICES LT 1638 CS8 Datasheet

FEATURES
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
Available in 14-Lead SO, 8-Lead MSOP and DFN Packages
+
U
APPLICATIO S
Battery- or Solar-Powered Systems
Portable Instrumentation Sensor Conditioning
Supply Current Sensing
Battery Monitoring
Micropower Active Filters
4mA to 20mA Transmitters
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Over-The-Top is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
LT1638/LT1639
1.2MHz, 0.4V/μs
Over-The-Top Micropower
Rail-to-Rail Input and Output
Op Amps
U
DESCRIPTIO
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. For space limited applications the LT1638 is available in a 3mm x 3mm x 0.8mm dual fine pitch leadless package (DFN).
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 when the inputs are 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.
Over-The-Top® Comparator with
100mV Hysteresis Centered at 0mV
10k
V1
10k
V2
1M
V
CC
+
A
1/2 LT1638
1M
V
= 5V, VCM = 0V TO 44V, tPD = 27μs
CC
1M
U
Output Voltage vs Input Voltage
V
CC
V
1M
CC
+
B
1/2 LT1638
V0
1638/39 TA01
5V
0V
20mV/DIV
1638/39 TA02
16389fd
1
LT1638/LT1639
1 2 3 4
OUT A
–IN A +IN A
V
8 7 6 5
V+ OUT B –IN B +IN B
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
A
B
TOP VIEW
S PACKAGE
14-LEAD PLASTIC SO
N PACKAGE
14-LEAD PDIP
1
2
3
4
5
6
7
14
13
12
11
10
9
8
A
B
C
OUT A
–IN A
+IN A
V
+
+IN B
–IN B
OUT B
OUT D
–IN D
+IN D
V
+IN C
– IN C
OUT C
D
WW
W
ABSOLUTE MAXIMUM RATINGS
U
(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
U
W
U
PACKAGE/ORDER INFORMATION
ORDER
PART NUMBER
LT1638CMS8 LT1638IMS8
MS8 PART
T
= 150°C, θJA = 300°C/W (MS8)
JMAX
MARKING*
LTCY
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
DD Package ......................................................125°C
Storage Temperature Range ................. –65°C to 150°C
DD Package ...................................... –65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER
PART NUMBER
TOP VIEW
1
OUT A
2
–IN A
+IN A
N8 PACKAGE 8-LEAD PDIP
A
3
4
V
T
= 150°C, θJA = 150°C/W (N8)
JMAX
= 150°C, θJA = 190°C/W (S8)
T
JMAX
+
8
V
7
OUT B
6
–IN B
B
5
+IN B
S8 PACKAGE
8-LEAD PLASTIC SO
LT1638CN8 LT1638IN8 LT1638CS8 LT1638IS8 LT1638HS8
S8 PART MARKING
1638 1638I 1638H
ORDER
PART NUMBER
TOP VIEW
LT1638CDD
+
8
V
OUT B
7
–IN B
6
B
+IN B
5
LT1638IDD
–IN A
+IN A
1OUT A
2
A
3
V
4
DD PART MARKING*
8-LEAD (3mm × 3mm) PLASTIC DFN
T
JMAX
UNDERSIDE METAL INTERNALLY CONNECTED TO V
DD PACKAGE
= 125°C, θJA = 160°C/W (NOTE 10)
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/
*The temperature grades are identified by a label on the shipping container.
2
LAAL
ORDER
PART NUMBER
LT1639CN LT1639IN LT1639CS LT1639IS LT1639HS
T
= 150°C, θJA = 130°C/W (N)
JMAX
= 150°C, θJA = 160°C/W (S)
T
JMAX
Consult LTC Marketing for parts specified with wider operating temperature ranges.
16389fd
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
The denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. V
= 3V, 0V; VS = 5V, 0V; VCM = V
S
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage LT1638 N, S Packages 200 600 μV
Input Offset Voltage Drift LT1638/LT1639 N, S Packages 26 μV/°C (Note 9) LT1638MS8, LT1638DD 2.5 7 μV/°C
I
OS
I
B
Input Offset Current 16 nA
Input Bias Current 20 50 nA
Input Noise Voltage 0.1Hz to 10Hz 1 μV
e
n
i
n
R
IN
C
IN
Input Noise Voltage Density f = 1kHz 20 nV/√Hz Input Noise Current Density f = 1kHz 0.3 pA/Hz Input Resistance Differential 1 2.5 MΩ
Input Capacitance 5pF Input Voltage Range 044V
CMRR Common Mode Rejection Ratio V
A
VOL
V
OL
V
OH
I
SC
Large-Signal Voltage Gain VS = 3V, VO = 500mV to 2.5V, RL = 10k 200 1500 V/mV
Output Voltage Swing Low VS = 3V, No Load 38 mV
Output Voltage Swing High VS = 3V, No Load 2.94 2.98 V
Short-Circuit Current (Note 2) VS = 3V, Short to GND 10 15 mA
= half supply, unless otherwise noted. (Note 4)
OUT
0°C TA 70°C 850 μV –40°C ≤ T
85°C 950 μV
A
LT1639 N, S Packages 300 700 μV 0°C T
70°C 950 μV
A
–40°C ≤ TA 85°C 1050 μV LT1638 MS8 Package 350 900 μV
0°C TA 70°C 1150 μV –40°C ≤ T
85°C 1450 μV
A
LT1638 DD Package 400 1100 μV 0°C T
70°C 1350 μV
A
–40°C ≤ TA 85°C 1450 μV
VCM = 44V (Note 5) 2.5 μA
VCM = 44V (Note 5) 830 μA V
= 0V 0.1 nA
S
Common Mode, VCM = 0V to 44V 1.4 5.5 MΩ
= 0V to VCC – 1V 88 98 dB
CM
V
= 0V to 44V (Note 8) 80 88 dB
CM
0°C TA 70°C 133 V/mV –40°C ≤ T
85°C 100 V/mV
A
VS = 5V, VO = 500mV to 4.5V, RL = 10k 400 1500 V/mV 0°C T
70°C 250 V/mV
A
–40°C ≤ TA 85°C 200 V/mV
VS = 3V, I
= 5mA 250 450 mV
SINK
VS = 5V, No Load 38 mV VS = 5V, I
VS = 3V, I
= 10mA 500 700 mV
SINK
= 5mA 2.25 2.40 V
SOURCE
VS = 5V, No Load 4.94 4.98 V VS = 5V, I
VS = 3V, Short to V
= 10mA 3.8 4.0 V
SOURCE
CC
VS = 5V, Short to GND 15 20 mA VS = 5V, Short to V
CC
LT1638C/LT1639C, LT1638I/LT1639I
P-P
15 25 mA
15 25 mA
16389fd
3
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 = V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PSRR Power Supply Rejection Ratio VS = 3V to 12.5V, V
Reverse Supply Voltage IS = –100μA per Amplifier 18 27 V Minimum Operating Supply Voltage 2.4 2.7 V
I
S
Supply Current per Amplifier 170 230 μA (Note 6)
GBW Gain Bandwidth Product f = 5kHz 650 1075 kHz
(Note 5) 0°C ≤ T
SR Slew Rate AV = –1, RL = 0.210 0.38 V/μs
(Note 7) 0°C ≤ T
The denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
I
OS
I
B
e
n
i
n
R
IN
C
IN
CMRR Common Mode Rejection Ratio V A
VOL
V
O
Input Offset Voltage LT1638 N, S Packages 250 800 μV
Input Offset Voltage Drift LT1638/LT1639 N, S Packages 26 μV/°C (Note 9) LT1638MS8, LT1638DD 2.5 7 μV/°C
Input Offset Current 16 nA Input Bias Current 20 50 nA Input Noise Voltage 0.1Hz to 10Hz 1 μV Input Noise Voltage Density f = 1kHz 20 nV/√Hz Input Noise Current Density f = 1kHz 0.3 pA/Hz Input Resistance Differential 1 2.5 MΩ
Input Capacitance 4.5 pF Input Voltage Range –15 29 V
Large-Signal Voltage Gain VO = ±14V, RL = 10k 200 500 V/mV
Output Voltage Swing No Load ±14.9 ±14.95 V
= 0V, unless otherwise noted. (Note 4)
OUT
= half supply, unless otherwise noted. (Note 4)
OUT
= VO = 1V 90 100 dB
CM
70°C 550 kHz
A
–40°C ≤ T
–40°C ≤ T
85°C 500 kHz
A
70°C 0.185 V/μs
A
85°C 0.170 V/μs
A
0°C TA 70°C 1000 μV –40°C ≤ T
85°C 1100 μV
A
LT1639 N, S Packages 350 900 μV 0°C T
70°C 1100 μV
A
–40°C ≤ TA 85°C 1200 μV LT1638 MS8 Package 400 1050 μV
0°C TA 70°C 1250 μV –40°C ≤ T
85°C 1550 μV
A
LT1638 DDPackage 450 1250 μV 0°C T
70°C 1450 μV
A
–40°C ≤ TA 85°C 1550 μV
Common Mode, V
= –15V to 29V 80 88 dB
CM
= –15V to 14V 500 MΩ
CM
0°C TA 70°C 125 V/mV –40°C ≤ T
I
OUT
85°C 100 V/mV
A
= ±10mA ±13.7 ±14.0 V
LT1638C/LT1639C, LT1638I/LT1639I
275 μA
LT1638C/LT1639C, LT1638I/LT1639I
P-P
4
16389fd
LT1638/LT1639
ELECTRICAL CHARACTERISTICS
range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, V
The denotes the specifications which apply over the specified temperature
= 0V, unless otherwise noted. (Note 4)
OUT
LT1638C/LT1639C, LT1638I/LT1639I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
SC
Short-Circuit Current (Note 2) Short to GND 25 40 mA
70°C 20 mA
0°C T
A
–40°C ≤ T
85°C 15 mA
A
PSRR Power Supply Rejection Ratio VS = ±1.5V to ±22V 90 100 dB I
S
Supply Current per Amplifier 205 280 μA
350 μA
GBW Gain Bandwidth Product f = 5kHz 750 1200 kHz
70°C 650 kHz
0°C T
A
–40°C ≤ T
85°C 600 kHz
A
SR Slew Rate AV = –1, RL = ∞, VO = ±10V, 0.225 0.4 V/μs
70°C 0.2 V/μs
0°C T
A
–40°C ≤ TA 85°C 0.18 V/μs
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 = V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
I
OS
I
B
CMRR Common Mode Rejection Ratio V
A
VOL
V
OL
V
OH
PSRR Power Supply Rejection Ratio VS = 3V to 12.5V, V
I
S
GBW Gain Bandwidth Product f = 5kHz 650 1075 kHz
SR Slew Rate AV = –1, RL = 0.21 0.38 V/μs
Input Offset Voltage LT1638S8 200 650 μV
Input Offset Voltage Drift (Note 9) 15 μV/°C Input Offset Current 15 nA
Input Bias Current 150 nA
Input Voltage Range 0.3 44 V
Large-Signal Voltage Gain VS = 3V, VO = 500mV to 2.5V, RL = 10k 200 1500 V/mV
Output Voltage Swing Low No Load 15 mV
Output Voltage Swing High VS = 3V, No Load 2.9 V
Minimum Supply Voltage 2.7 V Reverse Supply Voltage IS = –100μA 18 V Supply Current 170 230 μA
(Note 6)
(Note 5)
(Note 7)
= Half Supply unless otherwise specified. (Note 4)
OUT
LT1639S 300 750 μV
VCM = 44V (Note 5) 10 μA
VCM = 44V (Note 5) 100 μA
= 0.3V to VCC – 1V 76 dB
CM
V
= 0.3V to 44V 72 dB
CM
VS = 5V, VO = 500mV to 4.5V, RL = 10k 400 1500 V/mV
I
= 5mA 900 mV
SINK
VS = 5V, I
VS = 3V, I
= 10mA 1500 mV
SINK
= 5mA 2V
SOURCE
VS = 5V, No Load 4.9 V VS = 5V, I
= 10mA 3.5 V
SOURCE
= VO = 1V 80 dB
CM
LT1638H/LT1639H
3mV
3.2 mV
20 V/mV
35 V/mV
450 μA
350 kHz
0.1 V/μs
16389fd
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, V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
I
OS
I
B
CMRR Common Mode Rejection Ratio V A
VOL
V
O
PSRR Power Supply Rejection Ratio VS = ±1.5V to ±22V 84 dB
I
S
GBW Gain Bandwidth Product f = 5kHz 750 1200 kHz
SR Slew Rate AV = –1, RL = ∞, VO = ±10V, 0.225 0.4 V/μs
Note 1:
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: 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: 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 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.
Input Offset Voltage LT1638S8 250 850 μV
LT1639S 350 950 μV
Input Offset Voltage Drift (Note 9) 15 μV/°C Input Offset Current 25 nA Input Bias Current 250 nA
= –14.7V to 29V 72 dB
CM
Large-Signal Voltage Gain VO = ±14V, RL = 10k 200 500 V/mV
Output Voltage Swing No Load ±14.8 V
I
= ±5mA ±14 V
OUT
I
= ±10mA ±13.4 V
OUT
Minimum Supply Voltage ±1.35 V Supply Current 205 280 μA
Measure at V
Stresses beyond those listed under Absolute Maximum Ratings
The LT1638C/LT1639C are guaranteed to meet specified
= 0V, V
OUT
= ±5V 0.1 V/μs
O
= V– unless otherwise specified. (Note 4)
SHDN
LT1638H/LT1639H
3.4 mV
3.6 mV
15 V/mV
550 μA
400 kHz
Note 5: VS = 5V limits are guaranteed by correlation to VS = 3V and V
= ±15V or VS = ±22V tests.
S
Note 6: V V
S
Note 7: Guaranteed by correlation to slew rate at V V
S
Note 8: This specification implies a typical input offset voltage of 2mV at V
CM
Note 9: This parameter is not 100% tested. Note 10: The θ
spreading metal. Using expanded metal area on all layers of a board reduces this value.
= 3V limits are guaranteed by correlation to VS = 5V and
S
= ±15V or VS = ±22V tests.
= ±15V, and GBW at
= 3V and VS = ±15V tests.
= 44V and a maximum input offset voltage of 5mV at VCM = 44V.
specified for the DD package is with minimal PCB heat
JA
S
6
16389fd
W
COMMON MODE VOLTAGE (V)
4.0
INPUT BIAS CURRENT (nA)
10000
8000
6000
60
40
20
0
–20
–40
5.6
1638/39 G03
4.4
4.8
5.2
44
TA = 125°C
TA = –55°C
TA = 25°C
VS = 5V, 0V
FREQUENCY (Hz)
1
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
10 100 1k
1638/39 G08
INPUT NOISE CURRENT DENSITY (pA/Hz)
U
TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Supply Voltage
300
280
260
240
220
200
180
160
140
120
SUPPLY CURRENT PER AMPLIFIER (μA)
100
515
0
10
SUPPLY VOLTAGE (V)
TA = 125°C
TA = 25°C
T
= –55°C
A
25 45
30
20
35
40
1638/39 G01
Minimum Supply Voltage
400
300
200
100
0
–100
–200
–300
CHANGE IN INPUT OFFSET VOLTAGE (μV)
–400
TA = 25°C
TA = 125°C
1
0
TOTAL SUPPLY VOLTAGE (V)
2
T
–55°C
A =
3
4
LT1638/LT1639
Input Bias Current vs Common Mode Voltage
5
1638/39 G02
Output Saturation Voltage vs Load Current (Output High)
1
VS = ±2.5V V
0.1
OUTPUT SATURATION VOLTAGE (V)
0.01
0.001
0.1Hz to 10Hz Noise Voltage
VS = ±2.5
NOISE VOLTAGE (400nV/DIV)
013579
= 30mV
OD
TA = 125°C
TA = 25°C
TA = –55°C
0.01 0.1 1 10
SOURCING LOAD CURRENT (mA)
2468
TIME (SEC)
1638/39 G04
1638/39 G07
Output Saturation Voltage vs Load Current (Output Low)
1
VS = ±2.5V
= 30mV
V
OD
0.1
0.01
OUTPUT SATURATION VOLTAGE (V)
0.001
0.001
0.01 0.1 1 10
SINKING LOAD CURRENT (mA)
TA = 125°C
TA = 25°C
TA = –55°C
1638/39 G05
Noise Voltage Density vs Frequency
70
60
50
40
30
20
10
INPUT NOISE VOLTAGE DENSITY (nV/Hz)
10
0
1
10 100 1k
FREQUENCY (Hz)
1638/39 G09
Output Saturation Voltage vs Input Overdrive
100
OUTPUT HIGH
10
OUTPUT LOW
OUTPUT SATURATION VOLTAGE (mV)
1
20 100
10
0
40
50
30
INPUT OVERDRIVE (mV)
Input Noise Current Density vs Frequency
VS = ±2.5V NO LOAD
807060
90
1638/39 G06
16389fd
7
LT1638/LT1639
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
Gain and Phase Shift vs Frequency
80
70
60
50
40
30
GAIN (dB)
20
10
0
–10
–20
1
GAIN
10 100 1000 FREQUENCY (kHz)
PHASE
Gain Bandwidth Product and Phase Margin vs Supply Voltage
1500
1400
1300
1200
1100
GAIN BANDWIDTH PRODUCT (kHz)
1000
515
10
0
TOTAL SUPPLY VOLTAGE (V)
PHASE MARGIN
GAIN BANDWIDTH
25 45
30
20
VS = ±2.5V
1638/39 G12
35
40
1638/39 G15
Gain Bandwidth Product vs Temperature
100
90
80
70
60
50
40
30
20
10
0
1500
f = 1kHz
1400
PHASE SHIFT (DEG)
1300
1200
1100
1000
900
GAIN BANDWIDTH PRODUCT (kHz)
800
–50
Gain Bandwidth Product and Phase Margin vs Load Resistance
60
50
40
30
20
10
1500
1400
PHASE MARGIN (DEG)
1300
1200
1100
1000
900
GAIN BANDWIDTH PRODUCT (kHz)
800
1
VS = ±15V
V
= ±2.5V
S
25
0
–25
TEMPERATURE (°C)
PHASE MARGIN
GAIN BANDWIDTH PRODUCT
LOAD RESISTANCE (kΩ)
10 100
50
VS = ±2.5V
= –1
A
V
= RG = 100k
R
F
f = 1kHz
75
100
1638/39 G13
1638/39 G17
Slew Rate vs Temperature
0.60
0.55
0.50
0.45
0.40
SLEW RATE (V/μs)
0.35
0.30
125
0.25 –50
–25
PSRR vs Frequency
60
50
40
30
20
10
0
–10
90
80
70
PHASE MARGIN (DEG)
60
50
40
30
NEGATIVE SUPPLY
20
10
0
POWER SUPPLY REJECTION RATIO (dB)
–10
1 10 100 1000
RISING, VS = ±15V
RISING, V
FALLING, V
FALLING, VS = ±15V
50
25
0
TEMPERATURE (°C)
POSITIVE SUPPLY
FREQUENCY (kHz)
= ±2.5V
S
= ±2.5V
S
75
VS = ±2.5V
100
1638/39 G14
1638/39 G16
125
CMRR vs Frequency
120
VS = ±15V
110
100
90
80
70
60
50
40
30
COMMON MODE REJECTION RATIO (dB)
20
1 10 100 1000
FREQUENCY (kHz)
8
1638/39 G18
Channel Separation vs Frequency
130
120
110
100
90
80
CHANNEL SEPARATION (dB)
70
60
0.1
1 10 100
FREQUENCY (kHz)
VS = ±15V
1638/39 G19
Output Impedance vs Frequency
10k
VS = ±2.5V
1k
100
AV = 100
10
OUTPUT IMPEDANCE (Ω)
1
0.1
0.1 10 100 1000
AV = 10
AV = 1
1
FREQUENCY (kHz)
1638/39 G20
16389fd
W
FREQUENCY (kHz)
0.1
OUTPUT SWING (V
P-P
)
1 10 100
1638/39 G23
35
30
25
20
15
10
5
0
DISTORTION 1% R
L
= 20k
VS = ±2.5V
VS = ±15V
OUTPUT VOLTAGE (V
P-P
)
THD + NOISE (%)
10
1
0.1
0.01
0.001 023
1638/39 G26
1
RL = 10k, f = 1kHz V
CM
= HALF SUPPLY
A
V
= –1, VS = ±1.5V
A
V
= –1, VS = 3V, 0V
A
V
= 1, VS = ±1.5V
A
V
= 1, VS = 3V, 0V
U
TYPICAL PERFORMANCE CHARACTERISTICS
LT1638/LT1639
Settling Time to 0.1% vs Output Step
10
VS = ±15V
8
6
4
2
0
–2
OUTPUT STEP (V)
–4
–6
–8
–10
0
AV = 1
AV = –1
AV = 1
515
10
SETTLING TIME (μs)
20
AV = –1
25
Total Harmonic Distortion + Noise vs Frequency
10
VS = 3V, 0V
= 2V
V
OUT
P-P
VCM = 1.2V
1
= 20k
R
L
0.1
30
1638/39 G21
35
Capacitive Load Handling, Overshoot vs Capacitive Load
100
VS = 5V, 0V
90
= 2.5V
V
CM
= 150μA
I
SOURCE
80
70
60
50
40
OVERSHOOT (%)
30
20
10
0
10 100 1000 10000
AV = 1
CAPACITIVE LOAD (pF)
AV = 5
AV = 10
Total Harmonic Distortion + Noise vs Load Resistance
10
VS = 3V TOTAL
= 1
A
V
= 2V
IN
AT 1kHz
P-P
VS = ±1.5V
= ±1V
V
IN
V
1
0.1
Undistorted Output Swing vs Frequency
1638/39 G22
Total Harmonic Distortion + Noise vs Output Voltage
THD + NOISE (%)
0.001
0.01
AV = –1
AV = 1
0.01 1 10 100
0.1 FREQUENCY (Hz)
1638/39 G24
THD + NOISE (%)
0.01
0.001
VS = 3V, 0V
= 0.5V TO 2.5V
V
IN
VS = 3V, 0V
= 0.2V TO 2.2V
V
IN
0.1 10 100
LOAD RESISTANCE TO GROUND (kΩ)
1
1638/39 G25
Open-Loop Gain Large-Signal Response Small-Signal Response
VS = ±15V
RL = 2k
RL = 10k
RL = 50k
CHANGE IN INPUT OFFSET VOLTAGE (50μV/DIV)
–10V–20V
OUTPUT VOLTAGE (5V/DIV)
0V
10V 20V
1638/39 G27
S
A
V
= ±15V = 1
1638/39 G28
= ±15V
V
S
A
= 1
V
= 15pF
C
L
1638/39 G29V
16389fd
9
LT1638/LT1639
U
WUU
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. Increas- ing 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+.
The inputs are protected against excursions of 2V below V– by an internal 1k resistor in series with each input and a diode from the input to the negative supply. If the inputs can go more than 2V below V–, an additional external resistor is required. A 10k resistor will protect the input
against excursions as much as 10V below V
. The input stage of the LT1638/LT1639 incorporates phase reversal protection to prevent the output from phase reversing for inputs 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
V
+
IN
LT1638
0.22μF
150Ω
1000pF
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
16389fd
10
LT1638/LT1639
+
+
1/4 LT1639
+
1/4 LT1639
1/4 LT1639
D1 D2
V
CC
C1
V
OUT
V
EE
V
IN
R5 100k
R6 100k
1638/39 F02
LT1634-1.2V
R3
100k
R4
100k
R2
R1 1k
D3
D4
LT1634-1.2V
FOR R2 = 50k, C1 = 500pF, MAXIMUM SLOPE = 0.048V/μs
V
OUT
=
d
dt
1.2V
(R2)(C1)
D1 TO D4 = IN4148
U
WUU
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
U
TYPICAL APPLICATIONS
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, V will flow through capacitor C1, charging it linearly instead of exponentially. The maximum slope that the circuit will pass is equal to V
divided by (R2)(C1). No matter
DIODE
how fast the input changes the output will never change any faster than the dV/dT set by the diodes and (R2)(C).
DIODE
/R2,
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.
d
V
OUT(MAX)
dt
FOR R1 = 10k, R2 = 100k, C1 = 1000pF d
V
OUT(MAX)
dt
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 1V signal with a 2V pulse added to the sine wave; the circuit passes the 2kHz signal but limits the slope of the pulse.
D1
D2
V
IN
V
D
=
(R2)(C1)
= 0.006V/μs
Figure 1. Lowpass Slope Limiting Filter
R2
R1
+
C1
1/2 LT1638
P-P
V
OUT
1638/39 F01
, 2kHz input
Response of Slope Limiting Filter
V
OUT
V
IN
1638/39 TA02
Figure 2. Lowpass Slope Limiting Filter with 0 TC
11
16389fd
LT1638/LT1639
U
TYPICAL APPLICATIONS
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 propor
tional 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
5V
0.2Ω
200Ω
LOAD
I
LOAD
+
1/2 LT1638
V
OUT
= (2Ω)(I
LOAD
Q1 2N3904
0V TO 4.3V
2k
1638/39 F03
)
Figure 3. Positive Supply Rail Current Sense
WW
SI PLIFIED SCHE ATIC
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.
V
CC
LT1634-1.2
+
1/2 LT1638
Figure 4. Current Source
V
CC
R1
I
OUT
1638/39 F04
I
OUT
1.2V
=
R1
Q1
R1 6k
Q4
+
10μA
Q5
ONE AMPLIFIER
–IN
+IN
+
Q22
Q21
OUT
1638/39 SS
V
V
16389fd
Q2
D2
D1
R2 1k
Q7
R3 1k
Q6
D4
D5
Q8
Q9
Q10
Q11 Q12
Q13 Q14
R4 8k
R5 8k
Q15
Q3
D3
Q19
Q17 Q20
Q16 Q18
12
PACKAGE DESCRIPTION
0.675 ±0.05
U
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
LT1638/LT1639
R = 0.115
TYP
0.38 ± 0.10
85
3.5 ±0.05
1.65 ±0.05 (2 SIDES)2.15 ±0.05
PACKAGE OUTLINE
0.25 ± 0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
2.38 ±0.05
(2 SIDES)
0.50 BSC
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON TOP AND BOTTOM OF PACKAGE
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
0.889 ± 0.127 (.035 ± .005)
5.23
(.206)
MIN
0.42 ± 0.038
(.0165 ± .0015)
TYP
RECOMMENDED SOLDER PAD LAYOUT
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
3.20 – 3.45
(.126 – .136)
0.65
(.0256)
BSC
GAUGE PLANE
0.18
(.007)
0.254 (.010)
DETAIL “A”
DETAIL “A”
0° – 6° TYP
0.53 ± 0.152
(.021 ± .006)
3.00 ±0.10
(4 SIDES)
0.75 ±0.05
SEATING
PLANE
1.65 ± 0.10
(2 SIDES)
0.00 – 0.05
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
4.90 ± 0.152 (.193 ± .006)
(.043)
0.22 – 0.38
(.009 – .015)
TYP
0.25 ± 0.05
BOTTOM VIEW—EXPOSED PAD
8
7
6
12
3
1.10
MAX
0.65
(.0256)
BSC
2.38 ±0.10
(2 SIDES)
5
4
14
0.50 BSC
0.52
(.0205)
REF
3.00 ± 0.102 (.118 ± .004)
(NOTE 4)
0.86
(.034)
REF
0.127 ± 0.076 (.005 ± .003)
MSOP (MS8) 0204
(DD) DFN 1203
16389fd
13
LT1638/LT1639
U
PACKAGE DESCRIPTION
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
.065
(1.651)
.008 – .015
(0.203 – 0.381)
+.035
.325
–.015 +0.889
8.255
()
–0.381
NOTE:
1. DIMENSIONS ARE
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
INCHES
MILLIMETERS
TYP
.045 – .065
(1.143 – 1.651)
.100
(2.54)
BSC
N8 Package
(0.457 ± 0.076)
.130 ± .005
(3.302 ± 0.127)
.120
(3.048)
MIN
.018 ± .003
.020
(0.508)
MIN
N8 1002
.255 ± .015*
(6.477 ± 0.381)
.400*
(10.160)
MAX
87 6
12
3
5
4
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
INCHES
(MILLIMETERS)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.050 BSC
.245 MIN
.030
±
.005
TYP
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
(0.406 – 1.270)
× 45°
.016 – .050
.045 ±.005
±
.005
.160
0°– 8° TYP
.228 – .244
(5.791 – 6.197)
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.189 – .197
(4.801 – 5.004)
8
1
NOTE 3
7
2
5
6
.150 – .157
(3.810 – 3.988)
NOTE 3
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
SO8 0303
BSC
14
16389fd
PACKAGE DESCRIPTION
U
N Package
14-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
14
.255 ± .015*
(6.477 ± 0.381)
1213
.770*
(19.558)
MAX
11
LT1638/LT1639
8910
(7.620 – 8.255)
(0.203 – 0.381)
8.255
()
NOTE:
1. DIMENSIONS ARE
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
.050 BSC
N
.245
MIN
123 N/2
.300 – .325
.008 – .015
+.035
.325
–.015
+0.889 –0.381
2
.130 ± .005
(3.302 ± 0.127)
.020
(0.508)
MIN
.005
(0.127)
MIN
INCHES
MILLIMETERS
.120
(3.048)
MIN
S Package
14-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 ±.005
.160 ±.005
.228 – .244
(5.791 – 6.197)
31
.045 – .065
(1.143 – 1.651)
.100
(2.54)
BSC
14
N
6
.337 – .344
NOTE 3
11
7
.065
(1.651)
TYP
.018 ± .003
(0.457 ± 0.076)
N14 1103
10
8
9
.150 – .157
(3.810 – 3.988)
N/2
NOTE 3
5
4
(8.560 – 8.738)
13
12
.030 ±.005
TYP
RECOMMENDED SOLDER PAD LAYOUT
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS
SHALL NOT EXCEED .006" (0.15mm)
INCHES
(MILLIMETERS)
1
.010 – .020
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
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.
× 45°
.016 – .050
(0.406 – 1.270)
.053 – .069
(1.346 – 1.752)
0° – 8° TYP
.014 – .019
(0.355 – 0.483)
TYP
3
2
4
.050
(1.270)
BSC
5
7
6
.004 – .010
(0.101 – 0.254)
S14 0502
16389fd
15
LT1638/LT1639
TYPICAL APPLICATION
U
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
CHARGER
VOLTAGE
RS, 0.2Ω
I
BATT
LOAD
I
= = AMPS
BATT
(RS)(RG/RA)(GAIN)
RA, 2k
+
A
2k
R
A
',
1/4 LT1639
RB, 2k
+
B
= 12V
V
OUT
GAIN
1/4 LT1639
R
2k
B
',
+
V
BATT
V
OUT
loop when the battery is discharging. The current through Q1 or Q2 is proportional to the current in RS and this current flows into R D buffers and amplifies the voltage across R
and is converted into a voltage. Amp
G
. Amp C
G
compares the output of Amp A and Amp B to determine the polarity of current through R V
with S1 open is 1V/A. With S1 closed the scale factor
OUT
. The scale factor for
S
is 1V/100mA and currents as low as 500μA can be measured.
Q1
2N3904
+
Q2
2N3904
R
G
10k
S1
S1 = OPEN, GAIN = 1 S1 = CLOSED, GAIN = 10
10k
C
1/4 LT1639
LOGIC HIGH (5V) = CHARGING LOGIC LOW (0V) = DISCHARGING
+
D
1/4 LT1639
90.9k
= R
R
A
B
VS = 5V, 0V
1638/39 F05
LOGIC
V
OUT
Figure 5. Battery Monitor
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1078/LT1079 Dual/Quad 55μA Max, Single Supply, Precision Op Amps Input/Output Common Mode Includes Ground, 70μV V LT2078/LT2079 and 2.5μV/°C Drift (Max), 200kHz GBW, 0.07V/μs Slew Rate
LT1178/LT1179 Dual/Quad 17μA Max, Single Supply, Precison Op Amps Input/Output Common Mode Includes Ground, 70μV V LT2178/LT2179 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 V
OS(MAX)
, 500V/mV A
VOL(MIN)
, 400kHz GBW
LT1490/LT1491 Dual/Quad Over-The-Top Micropower, Rail-to-Rail Input and Single Supply Input Range: – 0.4V to 44V, Micropower 50μA
Output Op Amps per Amplifier, Rail-to-Rail Input and Output, 200kHz GBW
LT1636 Single Over-The-Top Micropower Rail-to-Rail Input and Output 55μA Supply Current, VCM Extends 44V above VEE,
Op Amp Independent of VCC; MSOP Package, Shutdown Function
LT 0707 REV D • PRINTED IN USA
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1998
OS(MAX)
OS(MAX)
16389fd
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