1
LT1637
1637fd
The LT
®
1637 is a rugged op amp that operates on all single
and split supplies with a total voltage of 2.7V to 44V. The
LT1637 has a gain-bandwidth product of 1.1MHz while
drawing less than 250µA of quiescent current. The LT1637
can be shut down, making the output high impedance and
reducing the quiescent current to only 3µA. The LT1637 is
reverse supply protected: it draws virtually no current for re-
verse supply up to 25V. The input range of the LT1637 in-
cludes both supplies and the output swings to both supplies.
Unlike most micropower op amps, the LT1637 can drive
heavy loads; its rail-to-rail output drives 25mA. The LT1637
is unity-gain stable into all capacitive loads up to 4700pF
when optional 0.22µF and 150Ω compensation is used.
The LT1637 has a unique input stage that operates and
remains high impedance when above the positive supply.
The inputs take 44V both differential and common mode,
even when operating on a 3V supply. Built-in resistors
protect the inputs for faults below the negative supply up
to 22V. There is no phase reversal of the output for inputs
5V below V
EE
or 44V above V
EE
, independent of V
CC
.
The LT1637 op amp is available in the 8-pin MSOP, PDIP
and SO packages. For space limited applications, the
LT1637 is available in a 3mm × 3mm × 0.8mm dual fine
pitch leadless package (DFN).
■
Battery or Solar Powered Systems:
Portable Instrumentation
Sensor Conditioning
■
Supply Current Sensing
■
Battery Monitoring
■
MUX Amplifiers
■
4mA to 25mA Transmitters
■
Operates with Inputs Above V
+
■
Rail-to-Rail Input and Output
■
Micropower: 250µA Supply Current Max
■
Operating Temperature Range: – 55°C to 125°C
■
Gain-Bandwidth Product: 1.1MHz
■
Slew Rate: 0.4V/µs
■
Low Input Offset Voltage: 350µV Max
■
Single Supply Input Range: –0.4V to 44V
■
High Output Current: 25mA Min
■
Specified on 3V, 5V and ±15V Supplies
■
Output Shutdown
■
Output Drives 4700pF with Output Compensation
■
Reverse Battery Protection to 25V
■
High Voltage Gain: 800V/mV
■
High CMRR: 110dB
■
Available in 8-Lead MSOP, PDIP and SO Packages;
and a Tiny (3mm × 3mm × 0.8mm) DFN Package
Over-The-Top
®
Current Source with Shutdown
SHDN
I
OUT
LT1004-1.24.7µF
2k
*OPTIONAL FOR LOW OUTPUT CURRENTS,
R* = R
R
4V TO 44V
TP0610
1637 TA01
R*
–
+
LT1637
I
OUT
=
e.g., 10mA = 120Ω
1.2
R
+
V
SHDN
6V
4V
2V
0V
10mA
5mA
0mA
I
OUT
100µs/DIV
Switchable Precision Current Source Current Source Timing
APPLICATIO S
U
TYPICAL APPLICATIO
U
1.1MHz, 0.4V/µs
Over-The-Top Micropower, Rail-To-Rail
Input and Output Op Amp
FEATURES
DESCRIPTIO
U
1637 TA01b
, 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.
2
LT1637
1637fd
ORDER PART
NUMBER
Total Supply Voltage (V
+
to V
–
) .............................. 44V
Input Differential Voltage ......................................... 44V
Input Current ...................................................... ±25mA
Shutdown Pin Voltage Above V
–.....................................
32V
Shutdown Pin Current ........................................ ±10mA
Output Short-Circuit Duration (Note 2) .........Continuous
Operating Temperature Range (Note 3)
LT1637C/LT1637I .............................. –40°C to 85°C
LT1637H .......................................... –40°C to 125°C
LT1637MP......................................... –55°C to 125°C
*The temperature grades are identified by a label on the shipping container. Consult factory for parts specified with wider operating temperature ranges.
(Note 1)
ORDER PART
NUMBER
S8 PART
MARKING
1637
1637I
1637H
1637MP
LT1637CN8
LT1637CS8
LT1637IN8
LT1637IS8
LT1637HS8
LT1637MPS8
1
2
3
4
8
7
6
5
TOP VIEW
NULL
V
+
OUT
SHDN
NULL
–IN
+IN
V
–
S8 PACKAGE
8-LEAD PLASTIC SO
N8 PACKAGE
8-LEAD PDIP
T
JMAX
= 150°C, θ
JA
= 150°C/W (N8)
T
JMAX
= 150°C, θ
JA
= 190°C/W (S8)
PACKAGE/ORDER I FOR ATIO
UUW
ABSOLUTE AXI U RATI GS
W
WW
U
Specified Temperature Range (Note 4)
LT1637C/LT1637I .............................. –40°C to 85°C
LT1637H .......................................... –40°C to 125°C
LT1637MP......................................... –55°C to 125°C
Junction Temperature........................................... 150°C
Junction Temperature (DD Package) ................... 125°C
Storage Temperature Range ................. – 65°C to 150°C
Storage Temperature Range
(DD Package) ....................................... – 65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
1
2
3
4
NULL
–IN
+IN
V
–
8
7
6
5
NULL
V
+
OUT
SHDN
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
MS8 PART*
MARKING
LTIE
LTIE
LT1637CMS8
LT1637IMS8
T
JMAX
= 150°C, θ
JA
= 250°C/W
ORDER PART
NUMBER
DD PART*
MARKING
LAAK
LAAK
LT1637CDD
LT1637IDD
TOP VIEW
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
5
6
7
8
4
3
2
1NULL
–IN A
+IN A
V–
NULL
V+
OUT
SHDN
LT1637C/LT1637I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage N8, S8 Packages 100 350 µV
0°C ≤ T
A
≤ 70°C●550 µV
–40°C ≤ T
A
≤ 85°C●700 µV
MS8 Package 100 350 µV
0°C ≤ T
A
≤ 70°C●750 µV
–40°C ≤ T
A
≤ 85°C●1100 µV
DD Package 125 550 µV
0°C ≤ T
A
≤ 70°C●950 µV
–40°C ≤ T
A
≤ 85°C●1100 µV
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA ≤ 85°C, otherwise
specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VSHDN = V–,VCM = VOUT = half supply unless otherwise specified. (Note 4)
3V 5VA
U
D ELECTRICAL CHARACTERISTICS
T
JMAX
= 125°C, θ
JA
= 160°C/W (NOTE 2)
UNDERSIDE METAL CONNECTED TO V
–
3
LT1637
1637fd
Input Offset Voltage Drift (Note 9) N8, S8 Packages, – 40°C ≤ T
A
≤ 85°C●13µV/°C
MS8 Package, – 40°C ≤ T
A
≤ 85°C●26µV/°C
DDPackage, – 40°C ≤ T
A
≤ 85°C●26µV/°C
I
OS
Input Offset Current ●0.4 6.0 nA
V
CM
= 44V (Note 5) ●2.5 µA
I
B
Input Bias Current ●20 50 nA
V
CM
= 44V (Note 5) ●23 60 µA
V
S
= 0V 0.1 nA
Input Noise Voltage 0.1Hz to 10Hz 0.6 µV
P-P
e
n
Input Noise Voltage Density f = 1kHz 27 nV/√Hz
i
n
Input Noise Current Density f = 1kHz 0.08 pA/√Hz
R
IN
Input Resistance Differential 1 2.6 MΩ
Common Mode, V
CM
= 0V to 44V 0.7 1.4 MΩ
C
IN
Input Capacitance 4pF
Input Voltage Range ●044V
CMRR Common Mode Rejection Ratio V
CM
= 0V to (V
CC
– 1V) ●88 110 dB
(Note 5) V
CM
= 0V to 44V (Note 8) ●80 98 dB
A
VOL
Large-Signal Voltage Gain V
S
= 3V, V
O
= 500mV to 2.5V, R
L
= 10k 150 400 V/mV
V
S
= 3V, 0°C ≤ T
A
≤ 70°C●100 V/mV
V
S
= 3V, – 40°C ≤ T
A
≤ 85°C●75 V/mV
V
S
= 5V, V
O
= 500mV to 4.5V, R
L
= 10k 300 800 V/mV
V
S
= 5V, 0°C ≤ T
A
≤ 70°C●200 V/mV
V
S
= 5V, – 40°C ≤ T
A
≤ 85°C●150 V/mV
V
OL
Output Voltage Swing LOW No Load ●38 mV
I
SINK
= 5mA ●325 700 mV
V
S
= 5V, I
SINK
= 10mA ●580 1300 mV
V
OH
Output Voltage Swing HIGH V
S
= 3V, No Load ●2.94 2.975 V
V
S
= 3V, I
SOURCE
= 5mA ●2.25 2.67 V
V
S
= 5V, No Load ●4.94 4.975 V
V
S
= 5V, I
SOURCE
= 10mA ●3.80 4.45 V
I
SC
Short-Circuit Current (Note 2) V
S
= 3V, Short Output to Ground 10 14 mA
V
S
= 3V, Short Output to V
CC
15 45 mA
V
S
= 5V, Short Output to Ground 15 22 mA
V
S
= 5V, Short Output to V
CC
15 60 mA
PSRR Power Supply Rejection Ratio V
S
= 3V to 12.5V, V
CM
= V
O
= 1V ●90 98 dB
Minimum Supply Voltage ●2.7 V
Reverse Supply Voltage I
S
= –100µA●25 40 V
I
S
Supply Current 190 250 µA
(Note 6) ●295 µA
Supply Current, SHDN V
PIN5
= 2V, No Load (Note 6) ●312 µA
I
SHDN
Shutdown Pin Current V
PIN5
= 0.3V, No Load (Note 6) ●0.2 15 nA
V
PIN5
= 2V, No Load (Note 5) ●1.0 5 µA
V
PIN5
= 3.3V 2.5 µA
V
PIN5
= 5V 4.3 µA
Output Leakage Current, SHDN V
PIN5
= 2V, No Load (Note 6) ●0.02 1 µA
LT1637C/LT1637I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA ≤ 85°C, otherwise
specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VSHDN = V–,VCM = VOUT = half supply unless otherwise specified. (Note 4)
3V 5VA
U
D ELECTRICAL CHARACTERISTICS
4
LT1637
1637fd
LT1637C/LT1637I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage N8, S8 Packages 100 450 µV
0°C ≤ T
A
≤ 70°C●650 µV
–40°C ≤ T
A
≤ 85°C●800 µV
MS8 Package 100 450 µV
0°C ≤ T
A
≤ 70°C●800 µV
–40°C ≤ T
A
≤ 85°C●1150 µV
DD Package 125 650 µV
0°C ≤ T
A
≤ 70°C●1000 µV
–40°C ≤ T
A
≤ 85°C●1150 µV
Input Offset Voltage Drift (Note 9) N8, S8 Packages, – 40°C ≤ T
A
≤ 85°C●13µV/°C
MS8 Package, – 40°C ≤ T
A
≤ 85°C●26µV/°C
DD Package, –40°C ≤ T
A
≤ 85°C●26µV/°C
I
OS
Input Offset Current ●16 nA
I
B
Input Bias Current ●17 50 nA
Input Noise Voltage 0.1Hz to 10Hz 0.6 µV
P-P
e
n
Input Noise Voltage Density f = 1kHz 27 nV/√Hz
i
n
Input Noise Current Density f = 1kHz 0.08 pA/√Hz
R
IN
Input Resistance Differential 1 3 MΩ
Common Mode, V
CM
= –15V to 14V 2200 MΩ
C
IN
Input Capacitance 4pF
Input Voltage Range ●–15 29 V
CMRR Common Mode Rejection Ratio V
CM
= –15V to 29V ●80 110 dB
A
VOL
Large-Signal Voltage Gain V
O
= ±14V, R
L
= 10k 100 400 V/mV
0°C ≤ T
A
≤ 70°C●75 V/mV
–40°C ≤ T
A
≤ 85°C●50 V/mV
V
OL
Output Voltage Swing LOW No Load ●–14.997 –14.95 V
I
SINK
= 5mA ●–14.680 –14.25 V
I
SINK
= 10mA ●–14.420 –13.65 V
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA≤85°C, otherwise
specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V– unless otherwise specified. (Note 4)
±15V ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA≤85°C, otherwise
specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VSHDN = V–, VCM = VOUT = half supply unless otherwise specified. (Note 4)
3V 5VA
U
D ELECTRICAL CHARACTERISTICS
LT1637C/LT1637I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Shutdown Pin Current V
PIN5
= 32V, No Load (Note 5) ●20 150 µA
t
ON
Turn-On Time V
PIN5
= 5V to 0V, R
L
= 10k 45 µs
t
OFF
Turn-Off Time V
PIN5
= 0V to 5V, R
L
= 10k 3 µs
t
SETTLING
Settling Time 0.1% A
V
= 1, ∆V
O
= 2V 9 µs
GBW Gain-Bandwidth Product f = 10kHz 650 1000 kHz
(Note 5) 0°C ≤ T
A
≤ 70°C●550 kHz
–40°C ≤ T
A
≤ 85°C●500 kHz
SR Slew Rate A
V
= – 1, R
L
= ∞0.210 0.35 V/µs
(Note 7) 0°C ≤ T
A
≤ 70°C●0.185 V/µs
–40°C ≤ T
A
≤ 85°C●0.170 V/µs
5
LT1637
1637fd
V
OH
Output Voltage Swing HIGH No Load ●14.9 14.967 V
I
SOURCE
= 5mA ●14.2 14.667 V
I
SOURCE
= 10mA ●13.7 14.440 V
I
SC
Short-Circuit Current (Note 2) Short Output to GND ±25 ±31.7 mA
0°C ≤ T
A
≤ 70°C●±20 mA
–40°C ≤ T
A
≤ 85°C●±15 mA
PSRR Power Supply Rejection Ratio V
S
= ±1.5V to ±22V ●90 115 dB
Minimum Supply Voltage ●±1.35 V
I
S
Supply Current 230 300 µA
●370 µA
Positive Supply Current, SHDN V
PIN5
= – 20V, V
S
= ±22V, No Load ●640 µA
I
SHDN
Shutdown Pin Current V
PIN5
= – 21.7V, V
S
= ±22V, No Load ●0.3 15 nA
V
PIN5
= – 20V, V
S
= ±22V, No Load ●0.9 8 µA
Maximum Shutdown Pin Current V
PIN5
= 32V, V
S
= ±22V ●20 150 µA
Output Leakage Current, SHDN V
PIN5
= – 20V, V
S
= ±22V, No Load ●0.02 2 µA
V
L
Shutdown Pin Input Low Voltage V
S
= ±22V ●–21.7 –21.6 V
V
H
Shutdown Pin Input High Voltage V
S
= ±22V ●–20.8 –20.0 V
t
ON
Turn-On Time V
PIN5
= – 10V to – 15V, R
L
= 10k 35 µs
t
OFF
Turn-Off Time V
PIN5
= – 15V to – 10V, R
L
= 10k 3 µs
GBW Gain-Bandwidth Product f = 10kHz 750 1100 kHz
0°C ≤ T
A
≤ 70°C●650 kHz
–40°C ≤ T
A
≤ 85°C●600 kHz
SR Slew Rate A
V
= – 1, R
L
= ∞, V
O
= ±10V, Measure at V
O
= ±5V 0.225 0.4 V/µs
0°C ≤ T
A
≤ 70°C●0.200 V/µs
–40°C ≤ T
A
≤ 85°C●0.180 V/µs
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA≤85°C, otherwise
specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V– unless otherwise specified. (Note 4)
LT1637C/LT1637I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
±15V ELECTRICAL CHARACTERISTICS
6
LT1637
1637fd
LT1637H/LT1637MP
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage 100 450 µV
●3mV
Input Offset Voltage Drift (Note 9) ●310µV/°C
I
OS
Input Offset Current ●15 nA
V
CM
= 44V (Note 5) ●10 µA
I
B
Input Bias Current ●150 nA
V
CM
= 44V (Note 5) ●100 µA
Input Voltage Range ●0.3 44 V
CMRR Common Mode Rejection Ratio V
CM
= 0.3V to (V
CC
– 1V) ●72 dB
(Note 5) V
CM
= 0.3V to 44V ●74 dB
A
VOL
Large-Signal Voltage Gain V
S
= 3V, V
O
= 500mV to 2.5V, R
L
= 10k 150 400 V/mV
●20 V/mV
V
S
= 5V, V
O
= 500mV to 4.5V, R
L
= 10k 300 800 V/mV
●35 V/mV
V
OL
Output Voltage Swing LOW No Load ●15 mV
I
SINK
= 5mA ●900 mV
V
S
= 5V, I
SINK
= 10mA ●1500 mV
V
OH
Output Voltage Swing HIGH V
S
= 3V, No Load ●2.90 V
V
S
= 3V, I
SOURCE
= 5mA ●2.05 V
V
S
= 5V, No Load ●4.90 V
V
S
= 5V, I
SOURCE
= 10mA ●3.50 V
PSRR Power Supply Rejection Ratio V
S
= 3V to 12.5V, V
CM
= V
O
= 1V ●80 dB
Minimum Supply Voltage ●2.7 V
Reverse Supply Voltage I
S
= –100µA●23 V
I
S
Supply Current (Note 6) 190 250 µA
●400 µA
Supply Current, SHDN V
PIN5
= 2V, No Load (Note 6) ●15 µA
I
SHDN
Shutdown Pin Current V
PIN5
= 0.3V, No Load (Note 6) ●200 nA
V
PIN5
= 2V, No Load (Note 5) ●7µA
Output Leakage Current, SHDN V
PIN5
= 2V, No Load (Note 6) ●5µA
Maximum Shutdown Pin Current V
PIN5
= 32V, No Load (Note 5) ●200 µA
GBW Gain-Bandwidth Product f = 10kHz (Note 5) 650 1000 kHz
●350 kHz
SR Slew Rate A
V
= – 1, R
L
= ∞ (Note 7) 0.210 0.35 V/µs
●0.1 V/µs
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA≤125°C for LT1637H and
–55°C ≤ TA ≤ 125°C for LT1637MP. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply unless otherwise specified. (Note 4)
3V 5VA
U
D ELECTRICAL CHARACTERISTICS
7
LT1637
1637fd
The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA≤125°C for LT1637H and
–55°C ≤ TA ≤ 125°C for LT1637MP. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V–
, unless otherwise specified. (Note 4)
±15V ELECTRICAL CHARACTERISTICS
LT1637H/LT1637MP
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage 100 550 µV
●3.4 mV
Input Offset Voltage Drift (Note 9) ●311µV/°C
I
OS
Input Offset Current ●25 nA
I
B
Input Bias Current ●250 nA
CMRR Common Mode Rejection Ratio V
CM
= –14.7V to 29V ●72 dB
A
VOL
Large-Signal Voltage Gain V
O
= ±14V, R
L
= 10k 100 400 V/mV
●4V/mV
V
O
Output Voltage Swing No Load ●±14.8 V
I
OUT
= ±5mA ●±14.0 V
I
OUT
= ±10mA ●±13.4 V
PSRR Power Supply Rejection Ratio V
S
= ±1.5V to 22V ●84 dB
Minimum Supply Voltage ●±1.35 V
I
S
Supply Current 230 300 µA
●500 µA
Positive Supply Current, SHDN V
PIN5
= –20V, V
S
= ±22V, No Load ●60 µA
I
SHDN
Shutdown Pin Current V
PIN5
= –21.7V, V
S
= ±22V, No Load ●200 nA
V
PIN5
= –20V, V
S
= ±22V, No Load ●10 µA
Maximum Shutdown Pin Current V
PIN5
= 32V, V
S
= ±22V ●200 µA
Output Leakage Current, SHDN V
PIN5
= –20V, V
S
= ±22V, No Load ●100 µA
V
L
Shutdown Pin Input Low Voltage V
S
= ±22V ●–21.7 V
V
H
Shutdown Pin Input High Voltage V
S
= ±22V ●–20 V
GBW Gain-Bandwidth Product f = 10kHz 750 1100 kHz
●400 kHz
SR Slew Rate A
V
= – 1, R
L
= ∞, V
O
= ±10V, 0.225 0.4 V/µs
Measure at V
O
= ±5V ●0.1 V/µs
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: A heat sink may be required to keep the junction temperature
below absolute maximum. The θ
JA
specified for the DD package is with
minimal PCB heat spreading metal. Using expanded metal area on all layers
of a board reduces this value.
Note 3: The LT1637C and LT1637I are guaranteed functional over the
operating temperature range of –40°C to 85°C. The LT1637H is guaranteed
functional over the operating temperature range of –40°C to 125°C. The
LT1637MP is guaranteed functional over the operating temperature range
–55°C to 125°C.
Note 4: The LT1637C is guaranteed to meet specified performance from
0°C to 70°C. The LT1637C is designed, characterized and expected to meet
specified performance from –40°C to 85°C but is not tested or QA
sampled at these temperatures. The LT1637I is guaranteed to meet
specified performance from –40°C to 85°C. The LT1637H is guaranteed to
meet specified performance from –40°C to 125°C and the LT1637MP is
guaranteed to meet specified performance from –55°C to 125°C.
Note 5: V
S
= 5V limits are guaranteed by correlation to V
S
= 3V and
V
S
= ±15V or V
S
= ±22V tests.
Note 6: V
S
= 3V limits are guaranteed by correlation to V
S
= 5V and
V
S
= ±15V or V
S
= ±22V tests.
Note 7: Guaranteed by correlation to slew rate at V
S
= ±15V and GBW at
V
S
= 3V and V
S
= ±15V tests.
Note 8: This specification implies a typical input offset voltage of 650µV at
V
CM
= 44V and a maximum input offset voltage of 5.4mV at V
CM
= 44V.
Note 9: This parameter is not 100% tested.
8
LT1637
1637fd
Input Noise Current vs Frequency
0.1Hz to 10Hz Noise Voltage
Noise Voltage Density
vs Frequency
Output Saturation Voltage
vs Load Current (Output High)
Output Saturation Voltage
vs Input Overdrive
Output Saturation Voltage
vs Load Current (Output Low)
SOURCING LOAD CURRENT (mA)
0.0001 0.001
0.01
OUTPUT SATURATION VOLTAGE (V)
0.1
1
0.01 0.1 1 10 100
1637 G04
VS = 5V, 0V
VOD = 30mV
TA = 25°C
TA = 125°C
TA = –55°C
SINKING LOAD CURRENT (mA)
0.0001 0.001
0.001
0.01
OUTPUT SATURATION VOLTAGE (V)
0.1
1
10
0.01 0.1 1 10 100
1637 G05
VS = 5V, 0V
VOD = 30mV
TA = 125°C
TA = –55°C
TA = 25°C
INPUT OVERDRIVE (mV)
0
OUTPUT SATURATION VOLTAGE (mV)
60
80
100
80
1637 G06
40
20
50
70
90
30
10
020 40 60
10 90
30 50 70 100
OUTPUT HIGH
OUTPUT LOW
V
S
= 5V, 0V
NO LOAD
FREQUENCY (Hz)
1
INPUT NOISE CURRENT DENSITY (pA/√Hz)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
010 100 1000
1637 G09
VS = ±15V
FREQUENCY (Hz)
1
20
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
50
60
70
10 100 1000
1637 G08
40
30
VS = ±15V
TIME (s)
0
NOISE VOLTAGE (200nV/DIV)
8
1637 G07
246
19
35710
VS = ±2.5V
Supply Current vs Supply Voltage
Input Bias Current
vs Common Mode Voltage
Minimum Supply Voltage
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TOTAL SUPPLY VOLTAGE (V)
0 10203040
SUPPLY CURRENT (µA)
1637 G01
400
350
300
250
200
150
100
50
0
T
A
= 125°C
T
A
= 25°C
T
A
= –55°C
TOTAL SUPPLY VOLTAGE (V)
01 2 3 4 5
CHANGE IN INPUT OFFSET VOLTAGE (µV)
1637 G02
400
300
200
100
0
–100
–200
–300
–400
T
A
= 125°C
T
A
= –55°C
T
A
= 25°C
COMMON MODE VOLTAGE (V)
4 4.2 4.4 4.6 4.8 5 10 20 30 40 50
INPUT BIAS CURRENT (µA)
40
30
20
10
0.12
0.08
0.04
0
0.04
0.08
1637 G03
VS = 5V, 0V
TA = 125°C
TA = –55°C
TA = 25°C
9
LT1637
1637fd
Open-Loop Gain and Phase Shift
vs Frequency Slew Rate vs Temperature
Gain-Bandwidth Product
vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
UW
FREQUENCY (Hz)
1k
10
GAIN (dB)
PHASE SHIFT (DEG)
20
30
40
50
10k 100k 1M
1637 G10
0
–10
–20
–30
60
70
0
20
40
60
80
100
120
V
S
= ±2.5V
PHASE
GAIN
TEMPERATURE (°C)
–50
GAIN-BANDWIDTH PRODUCT (kHz)
1300
1200
1100
1000
900
800
700 25 75
1637 G11
–25 0 50 100 125
V
S
= ±15V
V
S
= ±1.5V
TEMPERATURE (°C)
–50
SLEW RATE (V/µs)
25
1637 G12
–25 0 50 75 100 125
0.7
0.6
0.5
0.4
0.3
0.2
0.1
FALLING, V
S
= ±1.5V
FALLING, V
S
= ±15V
RISING, V
S
= ±15V
RISING, V
S
= ±1.5V
Gain-Bandwidth Product and
Phase Margin vs Load Resistance
Undistorted Output Swing
vs FrequencyOutput Impedance vs Frequency
Gain-Bandwidth Product and
Phase Margin vs Supply Voltage CMRR vs Frequency PSRR vs Frequency
TOTAL SUPPLY VOLTAGE (V)
0
GAIN-BANDWIDTH PRODUCT (kHz)
PHASE MARGIN (DEG)
10 20 25 45
1637 G13
515 30 35 40
1300
1250
1200
1150
1100
1050
1000
55
50
45
40
35
30
25
PHASE MARGIN
GAIN BANDWIDTH
FREQUENCY (Hz)
1k
COMMON MODE REJECTION RATIO (dB)
10k 100k 1M
1637 G14
V
S
= ±1.5V
100
90
80
70
60
50
40
30
20
10
0
V
S
= ±15V
FREQUENCY (Hz)
1k
POWER SUPPLY REJECTION RATIO (dB)
10k 100k 1M
1637 G15
V
S
= ±2.5V
90
80
70
60
50
40
30
20
10
0
–10
POSITIVE SUPPLY
NEGATIVE SUPPLY
LOAD RESISTANCE (Ω)
1k
GAIN-BANDWIDTH PRODUCT (kHz)
PHASE MARGIN (DEG)
1400
1300
1200
1100
1000
900
800
700
600 10k 100k
1637 G16
50
45
40
35
30
25
20
15
10
PHASE MARGIN
GAIN BANDWIDTH
VS = ±2.5V
FREQUENCY (Hz)
100
0.1
OUTPUT IMPEDANCE (Ω)
10
10k
1k 100k 1M10k
1637 G17
1
100
1k
V
S
= ±2.5V
A
V
= 100
A
V
= 10
A
V
= 1
FREQUENCY (Hz)
100
20
OUTPUT SWING (VP-P)
25
30
35
1k 10k 100k
1637 G18
15
10
5
0
Vs = ±15V
Vs = ±2.5V
DISTORTION ≤ 1%
AV = 1
10
LT1637
1637fd
CHANGE IN INPUT OFFSET VOLTAGE
(50µV/DIV)
Open-Loop Gain
0V 10V
OUTPUT VOLTAGE (5V/DIV)
C
1637 G24 1637 G25
A: R
L
= 2k
B: R
L
= 10k
C: R
L
= 50k
Large-Signal Response
1637 G26
Small-Signal Response
A
B
–10V
Total Harmonic Distortion + Noise
vs Load Resistance
Total Harmonic Distortion + Noise
vs Output Voltage
LOAD RESISTANCE TO GROUND (Ω)
0.001
THD + NOISE (%)
0.01
0.1
1
1k 10k 100k
1637 G22
0.0001
100
VS = 3V TOTAL
AV = 1
VIN = 1.8VP-P AT 1kHz
VS = 3V, 0V
VIN = 0.3V TO 2.1V
VS = ±1.5V
VIN = ±0.9V
VS = 3V, 0V
VIN = 0.6V TO 2.4V
OUTPUT VOLTAGE (V
P-P
)
0.01
THD + NOISE (%)
1
10
023
1637 G23
0.001
1
0.1
R
L
= 10k
V
CM
= HALF SUPPLY
f = 1kHz
FOR A
V
= –1, R
G
= 100k
A
V
= –1, V
S
= 3V, 0V
A
V
= 1
V
S
= ±1.5V
A
V
= 1
V
S
= 3V, 0V
A
V
= 1
V
S
= 3V, 0V
A
V
= –1
V
S
= ±1.5V
V
S
= ±15V V
S
= ±15V
A
V
= –1
V
S
= ±15V
A
V
= 1
A
B
C
10V
– 10V
50mV
–50mV
Settling Time to 0.1%
vs Output Step
Total Harmonic Distortion + Noise
vs Frequency
Capacitive Load Handling,
Overshoot vs Capacitive Load
TYPICAL PERFOR A CE CHARACTERISTICS
UW
SETTLING TIME (µs)
0
–10
OUTPUT STEP (V)
–8
–4
–2
0
10
4
10 20
1637 G19
–6
6
8
2
30 40
A
V
= 1
A
V
= 1
A
V
= –1
V
S
= ±15V
A
V
= –1
CAPACITIVE LOAD (pF)
10
40
OVERSHOOT (%)
50
60
70
80
100 1000 10000
1637 G20
30
20
10
0
90
100
V
S
= ±2.5V
NO OUTPUT COMPENSATION
A
V
= 1 A
V
= 5
A
V
= 2
A
V
= 10
FREQUENCY (Hz)
10
0.0001
THD + NOISE (%)
0.01
10
100 10k 100k1k
1637 G21
0.001
0.1
1
VS = 3V, 0V
VOUT = 1.8VP-P
VCM = 1.2V
RL =10k
AV = –1
AV = 1
11
LT1637
1637fd
Supply Voltage
The positive supply pin of the LT1637 should be bypassed
with a small capacitor (about 0.01µF) within an inch of the
pin. When driving heavy loads an additional 4.7µF electro-
lytic capacitor should be used. When using split supplies,
the same is true for the negative supply pin.
The LT1637 is protected against reverse battery voltages
up to 25V. In the event a reverse battery condition occurs,
the supply current is typically less than 1nA.
When operating the LT1637 on total supplies of 30V or
more, the supply must not be brought up faster than 1µs.
This is especially true if low ESR bypass capacitors are
used. A series RLC circuit is formed from the supply lead
inductance and the bypass capacitor. 5Ω of resistance in
the supply or the bypass capacitor will dampen the tuned
circuit enough to limit the rise time.
Inputs
The LT1637 has two input stages, NPN and PNP (see the
Simplified Schematic), resulting in three distinct operat-
ing regions as shown in the Input Bias Current vs Common
Mode typical performance curve.
For input voltages about 0.9V or more below V
+
, the PNP
input stage is active and the input bias current is typically
–20nA. When the input voltage is about 0.5V or less from
V
+
, the NPN input stage is operating and the input bias
current is typically 80nA. Increases in temperature will
cause the voltage at which operation switches from the
PNP stage to the NPN 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 of
the NPN input stage allows the LT1637 to operate 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 23µA at room temperature. The
input offset voltage is typically 600µV when operating
above V
+
. The LT1637 will operate with its input 44V above
V
–
regardless of V
+
.
APPLICATIO S I FOR ATIO
WUUU
The inputs are protected against excursions as much as
22V below V
–
by an internal 1.3k resistor in series with
each input and a diode from the input to the negative
supply. There is no output phase reversal for inputs up to
5V below V
–
. There are no clamping diodes between the
inputs and the maximum differential input voltage is 44V.
Output
The output voltage swing of the LT1637 is affected by
input overdrive as shown in the typical performance
curves. When monitoring input voltages within 100mV of
V
+
, gain should be taken to keep the output from clipping.
The output of the LT1637 can be pulled up to 25V beyond
V
+
with less than 1nA of leakage current, provided that V
+
is less than 0.5V.
The normally reverse biased substrate diode from the
output to V
–
will cause unlimited currents to flow when the
output is forced below V
–
. If the current is transient and
limited to 100mA, no damage will occur.
The LT1637 is internally compensated to drive at least
200pF of capacitance under any output loading condi-
tions. 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 4700pF, at all
output currents.
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
nonlinear common mode rejection. Of course, if the op
amp is operating inverting there is no common mode
induced distortion. When the LT1637 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 LT1637 should be
operated single supply, with the output always sourcing
current and with the input voltage swing between ground
and (V
+
– 0.9V). See the Typical Performance Character-
istics curves.
12
LT1637
1637fd
SCHE ATIC
WW
SI PLIFIED
7V
+
4V
–
6OUT
81 NULLNULL
1637 SS
3
5
+IN
–IN
Q25
Q24
Q26
Q18
Q17
R6
7k
R8
400Ω
R5
7k
R3
1.3k
R4
1.3k
SHDN
R7
400Ω
Q16
Q15Q10
Q11
Q9
Q8
Q14
Q2
D5
Q13Q1
10µAQ20
Q23
D3
Q7
D1 D2
D4
Q6
Q4
Q5
2
R2
6k
R1
1M
Q3
Q19
Q21
Q22
Q12
APPLICATIO S I FOR ATIO
WUUU
Gain
The open-loop gain is less sensitive to load resistance
when the output is sourcing current. This optimizes per-
formance in single supply applications where the load is
returned to ground. The typical performance photo of
Open-Loop Gain for various loads shows the details.
Shutdown
The LT1637 can be shut down two ways: using the
shutdown pin or bringing V
+
to within 0.5V of V
–
. When V
+
is brought to within 0.5V of V
–
both the supply current and
output leakage current drop to less than 10nA. When the
shutdown pin is brought 1.2V above V
–
, the supply
current drops to about 3µA and the output leakage current
is less than 1µA, independent of V
+
. In either case the input
bias current is less than 0.1nA (even if the inputs are 44V
above the negative supply). Figure 1. Input Offset Nulling
LT1637
10k
1637 F01
V
–
1
8
The shutdown pin can be taken up to 32V above V
–
. The
shutdown pin can be driven below V
–
, however the pin
current through the substrate diode should be limited with
an external resistor to less than 10mA.
Input Offset Nulling
The input offset voltage can be nulled by placing a 10k
potentiometer between Pins 1 and 8 with its wiper to V
–
(see Figure 1). The null range will be at least ±3mV.
13
LT1637
1637fd
TYPICAL APPLICATIO S
U
–
+
LT1637
1637 TA03
VIN
0.22µF
CL ≤ 4700pF
150Ω
Positive Supply Rail Current Sense
Optional Output Compensation for
Capacitive Loads Greater Than 200pF
–
+
LT1637
IN1
(0V TO 44V)
IN2
(0V TO 44V)
2N5087
2N5210
1637 TA04
1M
V
OUT
1M
V
CC
100
1M
10k
HYSTERESIS =
10k
1M
3V TO 44V
–
+
LT1637
3V TO 44V
3V
R1
200Ω
R
S
0.2Ω
R2
2k
V
OUT
(0V TO 2.7V)
Q1
2N3904
1637 TA06
LOAD
I
LOAD
V
OUT
(R
S
)(R2/R1)
I
LOAD
=
Over-The-Top Comparator with Hysteresis
Lamp Outage Detector
Over-The-Top Current Sense
–
+
LT1637
5k
1M
5V TO 44V 3V
100k
0.5Ω
LAMP
ON/OFF
OUT
1637 TA05
OUT = 0V FOR GOOD BULB
3V FOR OPEN BULB
–
+
LT1637
5V
200Ω
200Ω
0.2Ω
2k
0V TO 4.3V
1637 TA02
VOUT = (2Ω)(ILOAD)
Q1
2N3904
LOAD ILOAD
14
LT1637
1637fd
PACKAGE DESCRIPTIO
U
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
3.00 ±0.10
(4 SIDES)
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
0.38 ± 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 ± 0.10
(2 SIDES)
0.75 ±0.05
R = 0.115
TYP
2.38 ±0.10
(2 SIDES)
14
85
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
0.00 – 0.05
(DD) DFN 1203
0.25 ± 0.05
2.38 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 ±0.05
(2 SIDES)2.15 ±0.05
0.50
BSC
0.675 ±0.05
3.5 ±0.05
PACKAGE
OUTLINE
0.25 ± 0.05
0.50 BSC
MSOP (MS8) 0204
0.53 ± 0.152
(.021 ± .006)
SEATING
PLANE
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
0.18
(.007)
0.254
(.010)
1.10
(.043)
MAX
0.22 – 0.38
(.009 – .015)
TYP
0.127 ± 0.076
(.005 ± .003)
0.86
(.034)
REF
0.65
(.0256)
BSC
0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
12
34
4.90 ± 0.152
(.193 ± .006)
8765
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
0.52
(.0205)
REF
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.889 ± 0.127
(.035 ± .005)
RECOMMENDED SOLDER PAD LAYOUT
0.42 ± 0.038
(.0165 ± .0015)
TYP
0.65
(.0256)
BSC
15
LT1637
1637fd
N8 1002
.065
(1.651)
TYP
.045 – .065
(1.143 – 1.651)
.130 ± .005
(3.302 ± 0.127)
.020
(0.508)
MIN
.018 ± .003
(0.457 ± 0.076)
.120
(3.048)
MIN
12 34
87 65
.255 ± .015*
(6.477 ± 0.381)
.400*
(10.160)
MAX
.008 – .015
(0.203 – 0.381)
.300 – .325
(7.620 – 8.255)
.325 +.035
–.015
+0.889
–0.381
8.255
()
NOTE:
1. DIMENSIONS ARE INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
.100
(2.54)
BSC
PACKAGE DESCRIPTIO
U
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 represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
SO8 0303
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1234
.150 – .157
(3.810 – 3.988)
NOTE 3
8765
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN .160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
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)
16
LT1637
1637fd
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2007
LT 0107 REV D • PRINTED IN USA
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TYPICAL APPLICATIO S
U
SHDN
V
IN
V
OUT
3V
150Ω
0.22µF
DROOP (LT1636 BUFFER): 200mV/s
DROOP INTO HIGH IMPEDANCE : LESS THAN 0.625mV/s
1637 TA07
–
+
LT1637
3V
–
+
LT1636
3V
0V
V
SAMPLE
V
OUT
2V/DIV
INPUT
SELECT
5V/DIV
0.2ms/DIV 1637 TA08
MUX Amplifier Waveforms
Sample-and-Hold
SHDN
VIN1
5kHz AT 4VP-P
INPUT SELECT
1kHz AT 5VP–P
SHDN
VIN2
10kHz AT 2VP–P
VOUT
5V
74HC04
1637 TA09
–
+
LT1637
5V
+
–
LT1637
MUX Amplifier
