LT6020/LT6020-1
Dual Micropower, 5V/µs
Precision Rail-to-Rail
Output Amplifier
Description
Features
Excellent Slew Rate to Power Ratio
n Slew Rate: 5V/μs
n Maximum Supply Current: 100μA/Amplifier
n Maximum Offset Voltage: 30μV
n Maximum Offset Voltage Drift: 0.5μV/°C
n High Dynamic Input Impedance
n Fast Recovery from Shutdown
n Maximum Input Bias Current: 3nA
n No Output Phase Inversion
n Gain Bandwidth Product: 400kHz
n Wide Specified Supply Range: 3V to 30V
n Operating Temperature Range: –40°C to 125°C
n DFN and MS8 Packages
n Rail-to-Rail Outputs
n
Applications
Precision Signal Processing
18-Bit DAC Amplifier
n Multiplexed ADC Applications
n Low Power Portable Systems
n Low Power Wireless Sensor Networks
The LT®6020 is a low power, enhanced slew rate, precision
operational amplifier. The proprietary circuit topology of
this amplifier gives excellent slew rate at low quiescent
power dissipation without compromising precision or
settling time. In addition, unique input stage circuitry
allows the input impedance to remain high during input
voltage steps as large as 5V. The combination of precision specs along with fast settling makes this part ideal
for MUX applications.
The low quiescent current of the LT6020 along with its
ability to operate on supplies as low as 3V make it useful
in portable systems. The LT6020-1 features a shutdown
mode which reduces the typical supply current to 1.4μA.
The LT6020 is available in the small 8-lead DFN and 8-lead
MSOP packages. The LT6020-1 is available in a 10-lead
DFN package.
n
L, LT, LTC, LTM, Linear Technology, SmartMesh and the Linear logo are registered trademarks
and SoftSpan is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Patent Pending.
n
Typical Application
16-Bit DAC with ±10V Output Swing
LT1019-2.5
IN
OUT
GND
0.1µF
3.8VDC TO 5.5VDC
20V Output Step Response
CS
5V/DIV
1µF
0.1µF
VOUT
5V/DIV
LTC2642
POWER-ON
RESET
CS
DIN
CLR
RFB
10pF
INV
–
VOUT
16-BIT DAC
15V
20µs/DIV
60201 TA01b
VOUT
1/2 LT6020
+
–15V
16-BIT DATA LATCH
1/2 LT6020
CONTROL
LOGIC
–
SCLK
REF
+
VDD
16-BIT SHIFT REGISTER
GND
LT5400-1
10kΩ MATCHED
RESISTOR NETWORK
60201 TA01a
60201fa
For more information www.linear.com/LT6020
1
LT6020/LT6020-1
Absolute Maximum Ratings
(Note 1)
Total Supply Voltage (V+ to V–)..................................36V
Differential Input Voltage (within Supplies)................36V
Input Voltage (DGND, EN) (Relative to V–).................36V
Input Current (+IN, –IN, DGND, EN)...................... ±10mA
Output Short-Circuit Duration........................... Indefinite
Operating and Specified Temperature Range
I-Grade.................................................–40°C to 85°C
H-Grade............................................. .–40°C to 125°C
Junction Temperature............................................ 150°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................... 300°C
Pin Configuration
TOP VIEW
TOP VIEW
OUT A
1
8 V+
–IN A
2
7 OUT B
+IN A
3
V–
4
A
9
B
6 –IN B
5 +IN B
OUT A
1
–IN A
2
+IN A
3
V–
4
DGND
5
10 V+
A
9 OUT B
11
B
8 –IN B
7 +IN B
6 EN
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
θJA = 43°C/W, θJC = 5.5°C/W
EXPOSED PAD (PIN 9) IS CONNECTED TO V– (PIN 4)
(PCB CONNECTION OPTIONAL)
θJA = 43°C/W, θJC = 5.5°C/W
EXPOSED PAD (PIN 11) IS CONNECTED TO V– (PIN 4)
(PCB CONNECTION OPTIONAL)
TOP VIEW
OUTA
–INA
+INA
V–
1
2
3
4
A
B
8
7
6
5
V+
OUTB
–INB
+INB
MS8 PACKAGE
8-LEAD PLASTIC MSOP
θJA = 163°C/W, θJC = 40°C/W
Order Information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT6020IDD#PBF
LT6020IDD#TRPBF
LGMC
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LT6020HDD#PBF
LT6020HDD#TRPBF
LGMC
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT6020IDD-1#PBF
LT6020IDD-1#TRPBF
LGKF
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LT6020HDD-1#PBF
LT6020HDD-1#TRPBF
LGKF
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT6020IMS8#PBF
LT6020IMS8#TRPBF
LTGJG
8-Lead Plastic MSOP
–40°C to 85°C
LT6020HMS8#PBF
LT6020HMS8#TRPBF
LTGJG
8-Lead Plastic MSOP
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
60201fa
2
For more information www.linear.com/LT6020
LT6020/LT6020-1
Electrical Characteristics
The l denotes the specifications which apply over the specified
temperature range, otherwise specifications are at TA = 25°C, VS = ±15V, VCM = VOUT = Mid-Supply, VDGND = 0V, VEN = 5V. DGND
and EN specifications only apply to the LT6020-1.
SYMBOL PARAMETER
VOS
Input Offset Voltage
∆VOSI
∆Temp
Input Offset Voltage Drift (Note 2)
∆VOSI
∆Time
Long Term Input Offset Voltage Stability
IB
Input Bias Current
IOS
Input Offset Current
CONDITIONS
MIN
DD Packages
TA = –40° to 85°C
TA = –40° to 125°C
l
l
MS8 Package
TA = –40° to 85°C
TA = –40° to 125°C
l
l
DD Packages
l
MS8 Package
l
TYP
MAX
UNITS
20
70
110
120
µV
µV
µV
5
30
70
80
µV
µV
µV
–0.8
±0.3
0.8
µV/°C
–0.5
±0.2
0.5
µV/°C
±0.2
l
µV/Mo
TA = –40° to 85°C
TA = –40° to 125°C
–3
–3
–10
±0.1
l
l
3
3
10
nA
nA
nA
TA = –40° to 85°C
TA = –40° to 125°C
–1
–1
–2
±0.1
l
l
1
1
2
nA
nA
nA
Input Noise Voltage
0.1Hz to 10Hz
1.1
µVP-P
en
Input Noise Voltage Density
f = 10Hz
f = 1kHz
50
46
nV/√Hz
nV/√Hz
in
Input Noise Current Density
f = 1kHz
37
fA/√Hz
CIN
Input Capacitance
Common Mode
Differential Mode
1.5
2.5
pF
pF
RIN
Input Resistance
Common Mode
Differential Mode
17
20
GΩ
MΩ
VICM
Common Mode Input Range
CMRR
Common Mode Rejection Ratio
VCM = –13.8V to 13.6V
PSRR
Supply Rejection Ratio
VS = 3V to 30V
AVOL
Large-Signal Voltage Gain
l
V– + 1.2
132
l
120
120
dB
dB
120
118
140
l
dB
dB
110
108
116
l
dB
dB
126
126
138
l
dB
dB
RL = 6.98kΩ, VOUT = ±14V
RL = 100kΩ, VOUT = ±14.5V
VOL
VOH
ISC
Output Swing Low (VOUT – V–)
Output Swing High (V+ – VOUT)
Short-Circuit Current
RL = 10kΩ
TA = –40° to 85°C
TA = –40° to 125°C
l
l
RL = 10kΩ
TA = –40° to 85°C
TA = –40° to 125°C
l
l
VOUT = 0V, Sourcing
TA = –40° to 85°C
TA = –40° to 125°C
l
l
5.5
5
VOUT = 0V, Sinking
TA = –40° to 85°C
TA = –40° to 125°C
l
l
5.5
5.5
V+ – 1.4
V
130
200
250
300
mV
mV
mV
100
140
165
190
mV
mV
mV
8
mA
mA
mA
11
mA
mA
mA
60201fa
For more information www.linear.com/LT6020
3
LT6020/LT6020-1
Electrical Characteristics
The l denotes the specifications which apply over the specified
temperature range, otherwise specifications are at TA = 25°C, VS = ±15V, VCM = VOUT = Mid-Supply, VDGND = 0V, VEN = 5V. DGND
and EN specifications only apply to the LT6020-1.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
SR
AVCL = 1, 10V Step
TA = –40° to 85°C
TA = –40° to 125°C
5
l
l
3
2.4
2.4
V/μs
V/μs
V/μs
AVCL = 1, 5V Step
TA = –40° to 85°C
TA = –40° to 125°C
1.4
1.1
1
2.4
l
l
V/μs
V/μs
V/μs
Gain-Bandwidth Product
fO = 10kHz
l
290
400
kHz
Minimum Supply Voltage
Guaranteed by PSRR
l
3
TA = –40° to 85°C
TA = –40° to 125°C
l
l
VEN = 0.8V
TA = –40° to 85°C
TA = –40° to 125°C
l
l
GBW
IS
Slew Rate
Supply Current per Amplifier
Supply Current in Shutdown
ts
Settling Time (AV = 1)
0.1% 5V Output Step
0.01% 5V Output Step
0.0015% 5V Output Step
0.0015% 10V Output Step
tON
Enable Time
AV = 1
MAX
UNITS
V
90
100
125
140
μA
μA
μA
1.4
3
3.2
3.6
μA
μA
μA
6
7.8
13.8
12.4
μs
μs
μs
μs
100
V–
µs
V+ – 3
V
VDGND
DGND Pin Voltage Range
l
IDGND
DGND Pin Current
l
–200
–400
nA
IEN
EN Pin Current
l
–100
–200
nA
VENL
EN Pin Input Low Voltage
Relative to DGND
l
0.8
V
VENH
EN Pin Input High Voltage
Relative to DGND
l
1.7
V
60201fa
4
For more information www.linear.com/LT6020
LT6020/LT6020-1
Electrical Characteristics
The l denotes the specifications which apply over the specified
temperature range, otherwise specifications are at TA = 25°C, VS = 3V, VCM = VOUT = Mid-Supply, VDGND = 0V, VEN = 3V. DGND and
EN pin specifications only apply to the LT6020-1.
SYMBOL PARAMETER
VOS
CONDITIONS
Input Offset Voltage
∆VOSI
∆Temp
Input Offset Voltage Drift (Note 2)
∆VOSI
∆Time
Long Term Input Offset Voltage Stability
IB
Input Bias Current
IOS
Input Offset Current
MIN
DD Packages
TA = –40° to 85°C
TA = –40° to 125°C
l
l
MS8 Package
TA = –40° to 85°C
TA = –40° to 125°C
l
l
DD Packages
l
MS8 Package
l
TYP
MAX
UNITS
20
100
140
150
µV
µV
µV
5
45
85
95
µV
µV
µV
–0.8
±0.3
0.8
µV/°C
–0.5
±0.2
0.5
µV/°C
±0.2
l
µV/Mo
±1
nA
±0.1
nA
Input Noise Voltage
0.1Hz to 10Hz
1.1
µVP-P
en
Input Noise Voltage Density
f = 10Hz
f = 1kHz
50
46
nV/√Hz
nV/√Hz
in
Input Noise Current Density
f = 1kHz
37
fA/√Hz
CIN
Input Capacitance
Common Mode
Differential Mode
1.5
2.5
pF
pF
RIN
Input Resistance
Common Mode
Differential Mode
17
20
GΩ
MΩ
VICM
Common Mode Input Range
CMRR
Common Mode Rejection Ratio
VCM = 1.2V to 1.6V
PSRR
Supply Rejection Ratio
VS = 3V to 30V
AVOL
Large-Signal Voltage Gain
l
V– + 1.2
VOL
VOH
ISC
Output Swing Low (VOUT
Output Swing High (V+ – VOUT)
Short-Circuit Current
V
125
dB
120
118
140
l
dB
dB
98
98
108
l
dB
dB
136
dB
RL = 6.98kΩ, VOUT = 0.5V to 2.5V
RL = 100kΩ, VOUT = 0.5V to 2.5V
– V–)
V+ – 1.4
RL = 10kΩ
TA = –40° to 85°C
TA = –40° to 125°C
l
l
RL = 10kΩ
TA = –40° to 85°C
TA = –40° to 125°C
l
l
VOUT = 1.5V, Sourcing
TA = –40° to 85°C
TA = –40° to 125°C
l
l
3.5
3.5
VOUT = 1.5V, Sinking
TA = –40° to 85°C
TA = –40° to 125°C
l
l
5.5
5.5
45
100
130
150
mV
mV
mV
55
80
90
100
mV
mV
mV
6
mA
mA
mA
8
mA
mA
mA
SR
Slew Rate (Note 3)
AVCL = –1, 2V Step
0.2
V/μs
GBW
Gain-Bandwidth Product
fO = 10kHz
400
kHz
Minimum Supply Voltage
Guaranteed by PSRR
l
3
V
60201fa
For more information www.linear.com/LT6020
5
LT6020/LT6020-1
Electrical Characteristics
The l denotes the specifications which apply over the specified
temperature range, otherwise specifications are at TA = 25°C, VS = 3V, VCM = VOUT = Mid-Supply, VDGND = 0V, VEN = 3V. DGND and
EN pin specifications only apply to the LT6020-1.
SYMBOL PARAMETER
IS
Supply Current per Amplifier
Supply Current in Shutdown
CONDITIONS
MIN
TA = –40° to 85°C
TA = –40° to 125°C
l
l
VEN = 0.8V
TA = –40° to 85°C
TA = –40° to 125°C
l
l
ts
Settling Time (AV = –1)
0.1% 2.4V Output Step
0.01% 2.4V Output Step
0.0015% 2.4V Output Step
tON
Enable Time
AV = 1
TYP
MAX
UNITS
85
95
120
135
μA
μA
μA
0.9
1.1
1.5
3
μA
μA
μA
12.4
21.2
39.2
μs
μs
μs
120
V–
µs
V+ – 3
VDGND
DGND Pin Voltage Range
IDGND
DGND Pin Current
–200
nA
IEN
EN Pin Current
–100
nA
VENL
EN Pin Input Low Voltage
Relative to DGND
l
VENH
EN Pin Input High Voltage
Relative to DGND
l
l
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: Guaranteed by design.
V
0.8
V
1.7
V
Note 3: The slew rate of the LT6020 increases with the size of the
input step. At lower supplies, the input step size is limited by the input
common mode range. This trend can be seen in the Typical Performance
Characteristics.
60201fa
6
For more information www.linear.com/LT6020
LT6020/LT6020-1
Typical
Performance Characteristics
TA = 25°C, VS = ±15V, RL = 100kΩ, unless
otherwise specified.
Typical Distribution of Input
Offset Voltage
Typical Distribution of Input
Offset Voltage
1400
600
400
NUMBER OF CHANNELS
800
2500
2000
1500
1000
200
500
–30
20
–20 –10
0
10
INPUT OFFSET VOLTAGE (µV)
0
30
–70
–50 –30 –10 0 10
30
50
INPUT OFFSET VOLTAGE (µV)
25
20
15
10
0
70
–0.80 –0.60 –0.40 –0.20
0
0.20 0.40
INPUT OFFSET VOLTAGE DRIFT (µV/°C)
60201 G32
60201 G33
Voltage Offset Shift vs Lead Free
IR Reflow
Typical Distribution of Input
Offset Voltage
100
14
350 UNITS
90 MS8 PACKAGE
12
NUMBER OF CHANNELS
80
NUMBER OF CHANNELS
30
5
60201 G31
70
60
50
40
30
40 PARTS
MS8 PACKAGE
10
20
8
6
4
2
10
0
144 UNITS
DD8 AND DD10
PACKAGES
35
3000
1000
0
40
14930 PARTS
3500 DD8 AND DD10 PACKAGES
NUMBER OF UNITS
NUMBER OF UNITS
4000
2932 PARTS
MS8 PACKAGE
1200
Typical Distribution of Input
Offset Voltage Drift
0
–0.50 –0.40 –0.30 –0.20 –0.10
0
0.10
INPUT OFFSET VOLTAGE DRIFT (µV/°C)
–2
0
2
4
6
8
10
INPUT VOLTAGE OFFSET SHIFT (µV)
60201 G34
5
Offset Voltage vs Input Common
Mode Voltage
30
40
4
30
2
1
0
–1
–2
–3
OFFSET VOLTAGE (µV)
20
3
OFFSET VOLTAGE (µV)
CHANGE IN INPUT OFFSET VOLTAGE (µV)
60201 G35
Offset Voltage vs Supply Voltage
Warm-Up Drift
10
0
2
3
4
5
TIME (ms)
6
7
60201 G01
–30
10
0
–20
–20
1
20
–10
10
–30
–4
–5
12
0
4
8 12 16 20 24 28
TOTAL SUPPLY VOLTAGE (V)
32
36
60201 G02
–40
–15
–10
5
10
–5
0
INPUT COMMON MODE VOLTAGE (V)
15
60201 G03
60201fa
For more information www.linear.com/LT6020
7
LT6020/LT6020-1
Typical
Performance Characteristics
TA = 25°C, VS = ±15V, RL = 100kΩ, unless
otherwise specified.
Input Bias Current vs
Temperature
Input Bias Current vs Differential
Input Voltage
4
0.1Hz to 10Hz Voltage Noise
1.00
INPUT BIAS CURRENT (µA)
INPUT BIAS CURRENT (nA)
0.75
3
2
1
0
0.50
IB–
IB+
0.25
500nV/DIV
0
–0.25
–0.50
–0.75
–1
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
–1.00
–6 –5 –4 –3 –2 –1 0 1 2 3 4 5
DIFFERENTIAL INPUT VOLTAGE (V)
60201 G04
Maximum Undistorted Output
Amplitude vs Frequency
100
1
10
100
FREQUENCY (Hz)
1k
10k
MAXIMUM UNDISTORTED OUTPUT VOLTAGE (VP-P)
VOLTAGE NOISE DENSITY (nV/√Hz)
1000
0.1
60201 G06
60201 G05
Voltage Noise Density vs
Frequency
10
0.01
1s/DIV
6
Large-Signal Transient Response
(5V Step)
35
THD < 40dBc
30
AV = 1
25
20
1V/DIV
15
10
5
0
0.1
1
FREQUENCY (kHz)
60201 G07
10µs/DIV
10
60201 G08
Large-Signal Transient Response
(10V Step)
Slew Rate vs Temperature
(5V Step)
Slew Rate vs Temperature
(10V Step)
5
7
AV = 1
SLEW RATE (V/µs)
SLEW RATE (V/µs)
RISING EDGE
3
FALLING EDGE
2
1
10µs/DIV
60201 G10
0
–50
RISING EDGE
6
4
2V/DIV
60201 G09
5
4
FALLING EDGE
3
2
1
–25
0
25
50
75
TEMPERATURE (°C)
100
125
60201 G11
0
–50
–25
50
75
0
25
TEMPERATURE (°C)
100
125
60201 G12
60201fa
8
For more information www.linear.com/LT6020
LT6020/LT6020-1
Typical Performance Characteristics
TA = 25°C, VS = ±15V, RL = 100kΩ unless
otherwise specified.
AV = 1
300pF
FALLING EDGE
7
6
SLEW RATE (V/µs)
Small-Signal Transient Response
100pF
45
5
4
3
2µs/DIV
60201 G14
30
20
15
10
5
5
10
15
20
25
INPUT STEP SIZE (VP-P)
0
30
60201 G15
–PSRR
100
+PSRR
60
40
20
0
0.01 0.1
1
140
140
120
120
100
80
60
40
CL = 330pF
AV = 1
1
10
100
1k 10k 100k
FREQUENCY (Hz)
1M
40
–180
20
–20
1
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
–225
10M
60201 G18
Output Impedance vs Frequency
1000
VOUT = ±14.5V
CL = 100pF
AV = 1
OUTPUT IMPEDANCE (Ω)
OPEN LOOP GAIN (dB)
130
120
110
100
90
80
–9
CL = 100pF
AV = –1
100k
FREQUENCY (Hz)
VS = 3V
140
–6
–12
10k
–135
60
Open Loop Gain vs Load
150
0
–3
80
60201 G17
Gain vs Frequency
–90
0
60201 G16
3
VS = 30V
100
20
0
0.1
10 100 1k 10k 100k 1M
FREQUENCY (Hz)
–45
OPEN LOOP PHASE (DEGREES)
COMMON MODE REJECTION RATIO (dB)
140
80
Open-Loop Gain and Phase
vs Frequency
CMRR vs Frequency
160
120
0 100 200 300 400 500 600 700 800 900 1000
CAPACITIVE LOAD (pF)
60201 G13
OPEN LOOP GAIN (dB)
0
PSRR vs Frequency
POWER SUPPLY REJECTION RATIO (dB)
VS = ±15V
25
1
GAIN (dB)
VS = ±1.5V
35
2
0
AV = 1
40
0pF
5mV/DIV
RISING EDGE
Overshoot vs Capacitive Load
50
AV = 1
OVERSHOOT (%)
Slew Rate vs Input Step
8
100
10
1
0.1
70
1M
60201 G19
60
0.1
1
LOAD CURRENT (mA)
10
60201 G20
0.01
100
1000
10k
100k
FREQUENCY (Hz)
1M
10M
60201 G21
60201fa
For more information www.linear.com/LT6020
9
LT6020/LT6020-1
Typical
Performance Characteristics
TA = 25°C, VS = ±15V, RL = 100kΩ unless
otherwise specified.
Shutdown Supply Current vs
Temperature
Supply Current vs Supply Voltage
125°C
120
85°C
100
25°C
80
–40°C
60
40
20
5
0
20
25
10
15
TOTAL SUPPLY VOLTAGE (V)
2.5
VS = 30V
1.5
1.0
I(V+)
200µA/DIV
VS = 3V
0.5
0
–50
30
VEN
5V/DIV
0V
2.0
–25
0
25
50
75
TEMPERATURE (°C)
100
60201 G22
Output Saturation Voltage vs
Source Current (Output High)
1
0V
VOUT
5V/DIV
0V
OUTPUT LOW SATURATION VOLTAGE (V)
1
AV = 1
VIN = 5VP-P AT 50kHz
TA = 125°C
TA = 85°C
0.1
TA = –40°C
TA = 25°C
0.01
0.1
100µs/DIV
60201 G24
1
LOAD CURRENT (mA)
10
TA = 125°C
TA = 85°C
0.1
TA = –40°C
TA = 25°C
0.01
0.1
1
LOAD CURRENT (mA)
60201 G27
Negative Output Overdrive
Recovery
AV = –100
AV = –100
VDGND = 0V
VEN = 5V
–60
10
60201 G26
Positive Output Overdrive
Recovery
Crosstalk vs Frequency
CROSSTALK (dB)
60201 G24
Output Saturation Voltage vs
Sink Current (Output Low)
VEN
5V/DIV
20µs/DIV
60201 G23
Enable/Disable Response
–40
0µA
125
OUTPUT HIGH SATURATION VOLTAGE (V)
140
0
Start-Up Response
3.0
SHUTDOWN SUPPLY CURRENT (µA)
SUPPLY CURRENT/AMPLIFIER (µA)
160
INPUT
200mV/DIV
OUTPUT
5V/DIV
0V
–80
–100
0V
INPUT
200mV/DIV
OUTPUT
5V/DIV
–120
–140
100
1k
10k
100k
FREQUENCY (Hz)
1M
60201 G28
100µs/DIV
100µs/DIV
60201 G29
60201 G30
60201fa
10
For more information www.linear.com/LT6020
LT6020/LT6020-1
Pin Functions
OUT: Amplifier Output.
–IN: Inverting Input of the Amplifier.
+IN: Noninverting Input of the Amplifier.
V–: Negative Power Supply. A bypass capacitor should be
used between supply pins and ground. Additional bypass
capacitance may be used between the power supply pins.
DGND (LT6020-1 Only): Reference for EN Pin. It is normally
tied to ground. DGND must be in the range from V– to V+
–3V. If grounded, V+ must be ≥ 3V. The EN pin threshold
is specified with respect to the DGND pin. DGND cannot
be floated.
EN (LT6020-1 Only): Enable Input. This pin must be
connected high, normally to V+, for the amplifiers to be
functional. EN is active high with the threshold approximately two diodes above DGND. EN cannot be floated.
The shutdown threshold voltage is specified with respect
to the voltage on the DGND pin.
V+: Positive Power Supply. A bypass capacitor should be
used between supply pins and ground. Additional bypass
capacitance may be used between the power supply pins.
Simplified Schematic
LT6020-1 ONLY
V+
LOAD
+IN
–IN
5k
CLASS AB
DRIVE
OUT
EN
200k
5k
200k
DGND
V–
60201 BD
Applications Information
Preserving Low Power Operation
The proprietary circuitry used in the LT6020 provides an
excellent combination of low power, low offset and enhanced slew rate. Normally an amplifier with higher supply
current would be required to achieve this combination of
slew rate and precision. Special care must be taken to
ensure that the low power operation is preserved.
The choice of feedback resistor values impacts several
op-amp parameters as noted in the feedback components section. It should also be noted that the output of
the amplifier must drive this network. For example, in a
gain of two with a total feedback resistance of 10kΩ and
an output voltage of 14V, the amplifier’s output will need
to supply 1.4mA of current. This current will ultimately
come from a supply.
60201fa
For more information www.linear.com/LT6020
11
LT6020/LT6020-1
Applications Information
The supply current of the LT6020 increases with large
differential input voltages. Normally, this does not impact
the low power nature of the LT6020 because the amplifier is forcing the two inputs to be at the same potential.
Conditions which cause differential input voltage to appear
should be avoided in order to preserve the low power dissipation of the LT6020. This includes but is not limited
to: operation as a comparator, excessive loading on the
output and overdriving the input.
Enhanced Slew Rate
The LT6020 uses a proprietary input stage which provides
an enhanced slew rate without sacrificing input precision
specs such as input offset voltage, common mode rejection
and noise. The unique input stage of the LT6020 allows the
output to quickly slew to its final value when large signal
input steps are applied. This enhanced slew characteristic
allows the LT6020 to quickly settle the output to 0.0015%
independent of input step size as shown in Figure 1. Typical micropower amplifiers cannot process large amplitude
signals with this speed. As shown in the Typical Performance curves, when the LT6020 is configured in unity
gain and a 10V step is applied to the input the output will
slew at 5V/µs. In this same configuration, a 5V input step
will slew the output at 2.4V/µs. Furthermore, a 0.7V input
step will lower the slew rate to 0.2V/µs. Note that for these
30
SETTLING TIME (µs)
The design of the input stage of the LT6020 is more sophisticated than that shown in the Simplified Schematic.
It uses both NPN and PNP input differential amplifiers to
sense the input differential voltage. As a result the specified input bias current can flow in or out of the input pins.
Multiplexer Applications/High Dynamic Input
Impedance
The LT6020 has features which make it desirable for
multiplexer applications, such as the application featured
on the back page of this data sheet. When the channels of
the multiplexer are cycled, the output of the multiplexer
can produce large voltage transitions. Normally, bipolar
amplifiers have back-to-back diodes between the inputs,
which will turn on when the input transient voltage exceeds
0.7V, causing a large transient current to be conducted
from the amplifier output stage back into the input driving
circuitry. The driving circuitry then needs to absorb this
current and settle before the amplifier can settle. The
LT6020 uses 5.5V Zener diodes to protect its inputs which
dramatically increases its input impedance with input steps
as large as 5V.
The LT6020 output is able to swing close to each power
supply rail, but the input stage is limited to operating
between V– + 1.2V and V+ – 1.4V. For many inverting
applications and noninverting gain applications, this is
largely inconsequential. Figure 2 shows the basic op amp
configurations, what happens to the op amp inputs and
whether or not the op amp must have rail-to-rail inputs.
20
15
0.0015%
10
0.01%
5
5
Input Bias Current
Achieving Rail-to-Rail Operation without
Rail-to-Rail Inputs
AV = 1
25
0
smaller inputs the LT6020 slew rate approaches the slew
rate more common in traditional micropower amplifiers.
10
15
20
OUTPUT STEP (VP-P)
25
60201 F01
Figure 1. Settling Time Is Essentially Flat
The circuit of Figure 3 shows an extreme example of the
inverting case. The input voltage at the 100k resistor can
swing ±13.5V and the LT6020 will output an inverted,
60201fa
12
For more information www.linear.com/LT6020
LT6020/LT6020-1
Applications Information
+
VREF
RG
VIN
+
VIN
–
VIN
–
RF
+
–
RF
60201 F02
RG
VREF
INVERTING: AV = –RF/RG
OP AMP INPUTS DO NOT MOVE,
BUT ARE FIXED AT DC BIAS
POINT VREF
NONINVERTING: AV = 1 + RF/RG
INPUTS MOVE BY AS MUCH AS
VIN, BUT THE OUTPUT MOVES
MORE
INPUT DOES NOT HAVE TO BE
RAIL-TO-RAIL
INPUT MAY NOT HAVE TO BE
RAIL-TO-RAIL
NONINVERTING: AV = 1
INPUTS MOVE BY AS MUCH AS
OUTPUT
INPUT MUST BE RAIL-TO-RAIL
FOR OVERALL CIRCUIT
RAIL-TO-RAIL PERFORMANCE
Figure 2. Some Op Amp Configurations Do Not Require Rail-to-Rail Inputs to Achieve Rail-to-Rail Outputs
±13.5V SWINGS
WELL OUTSIDE
SUPPLY RAILS
1.5V
±1.35V
OUTPUT
SWING
+
LT6020
VIN
100k, 0.1%
–
10k, 0.1%
–1.5V
1880 F03
Figure 3. Extreme Inverting Case: Circuit Operates Properly
with Input Voltage Swing Well Outside Op Amp Supply Rails
divided-by-ten version of the input voltage. The output
accuracy is limited by the resistors to 0.2%. Output
referred, this error becomes 2.7mV. The 30µV input offset
voltage contribution, plus the additional error due to input
bias current times the ~10k effective source impedance,
contribute only negligibly to error.
Phase Inversion
the specified input voltage range as shown in Figure 4.
However the open loop gain is significantly reduced. While
the output roughly tracks the input, the reduction in open
loop gain degrades the accuracy of the LT6020 in this
region. Exceeding the input common mode range also
causes a significant increase in input bias current as shown
in Figure 5. The output of the LT6020 is guaranteed over
the specified temperature range not to phase invert as long
as the input voltage does not exceed the supply voltage.
Preserving Input Precision
Preserving the input accuracy of the LT6020 requires
that the application circuit and PC board layout do not
20V
10V
VS =±15V
AV = 1
INPUT
+VCM LIMIT
OUTPUT
5V/DIV 0V
The LT6020 input stage is limited to operating between V– +
1.2V and V+ – 1.4V. Exceeding this common mode range will
cause the open loop gain to drop significantly. For a unity gain
amplifier, the output roughly tracks the input well beyond
–10V
–20V
–VCM LIMIT
200µs/DIV
60201 F04
Figure 4. No Phase Inversion
60201fa
For more information www.linear.com/LT6020
13
LT6020/LT6020-1
Applications Information
70
10pF
INPUT BIAS CURRENT (µA)
60
50
100k
40
30
–
20
100k
10
+
0
VIN
–10
VOUT
60201 F06
Figure 6. Stability with Parasitic Input Capacitance
–20
–30
–15
LT6020
CPAR
–10
–5
0
5
10
INPUT COMMON MODE VOLTAGE (V)
15
60201 F05
Figure 5. Increased Ib Beyond VICM
introduce errors comparable to or greater than the offset
of the amplifiers. Temperature differentials across the
input connections can generate thermocouple voltages of
tens of microvolts so the connections of the input leads
should be short, close together and away from heat dissipating components. Air currents across the board can
also generate temperature differentials.
As is the case with all amplifiers, a change in load
current changes the finite open loop gain. Increased load
current reduces the open loop gain as seen in the Typical
Performance Characteristics section. This results in a
change in input offset voltage. Under large signal conditions
with load currents of ±2mA the effective change in input
error is just tens of microvolts. In precision applications it
is important to consider amplifier loading when selecting
feedback resistor values as well as the loads on the device.
Feedback Components
Care must be taken to ensure that the pole formed by the
feedback resistors and the parasitic capacitance at the
inverting input does not degrade stability. For example, in
a gain of +2 configuration, with 100k feedback resistors
and a poorly designed circuit board layout with parasitic
capacitance of 10pF (amplifier + PC board) at the amplifier’s inverting input will cause the amplifier to have poor
phase margin due to a pole formed at 320kHz. An additional
capacitor of 10pF across the feedback resistor as shown
in Figure 6 will eliminate any ringing or oscillation.
Capacitive Loads
The LT6020 can drive capacitive loads up to 100pF in
unity gain. The capacitive load driving capability increases
as the amplifier is used in higher gain configurations. A
small series resistance between the output and the load
will further increase the amount of capacitance that the
amplifier can drive.
Shutdown Operation (LT6020-1)
The LT6020-1 shutdown function has been designed
to be easily controlled from single supply logic or
microcontollers. To enable the LT6020-1 when VDGND = 0V
the enable pin must be driven above 1.7V. Conversely, to
enter the low power shutdown mode the enable pin must
be driven below 0.8V. In a ±15V dual supply application
where VDGND = –15V, the enable pin must be driven above
~ –13.3V to enable the LT6020-1. If the enable pin is
driven below –14.2V the LT6020-1 enters the low power
shutdown mode. Note that to enable the LT6020-1 the
enable pin voltage can range from –13.3V to 15V whereas
to disable the LT6020-1 the enable pin can range from
–15V to –14.2V. Figure 7 shows examples of enable pin
control. While in shutdown, the outputs of the LT6020-1
are high impedance.
The LT6020-1 is typically capable of coming out of
shutdown within 100µs. This is useful in power sensitive
applications where duty cycled operation is employed
such as wireless mesh networks. In these applications the
system is in low power mode the majority of the time, but
then needs to wake up quickly and settle for an acquisition
before being powered back down to save power.
60201fa
14
For more information www.linear.com/LT6020
LT6020/LT6020-1
Applications Information
≥ –13.3V
ON
≤ –14.2V
+15
+
≥ 1.7V
≥ 1.7V
ON
ON
ON
≤ 0.8V
OFF
+15
+ OR
EN TO V
EN LOGIC
+
DGND
–
LT6020-1
–
≥ 1.7V
≤ 0.8V
OFF
+ OR
EN TO V
EN LOGIC
+
DGND
–
LT6020-1
–15
HIGH VOLTAGE
SPLIT SUPPLIES
ON
≤ –0.7V
≤ 0.8V
OFF
+30
≥ 0.2V
OFF
+3V
+ OR
EN TO V
EN LOGIC
+
DGND
–
LT6020-1
+1.5
+ OR
EN TO V
EN LOGIC
+
DGND
–
LT6020-1
OFF
+ OR
EN TO V
EN LOGIC
LT6020-1
–15
DGND
–1.5
HIGH VOLTAGE
SPLIT SUPPLIES
HIGH VOLTAGE
SINGLE SUPPLY
LOW VOLTAGE
SINGLE SUPPLY
LOW VOLTAGE
SPLIT SUPPLIES
60201 F07
Figure 7. LT6020-1 Enable Pin Control Examples
Typical Applications
High Open-Loop Gain Composite Amplifier
4.7pF
10k
VIN
LOAD
270pF
–
10k
1/2 LT6020
+
+
VOUT
1/2 LT6020
–
60201 F02a
Parallel Amplifiers Achieves 32nV/√Hz Noise, Doubles Output Drive and Lowers Offset
VIN
+
1/2 LT6020
–
100Ω
VOUT
+
100Ω
1/2 LT6020
–
60201 F02b
60201fa
For more information www.linear.com/LT6020
15
LT6020/LT6020-1
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698 Rev C)
0.70 ±0.05
3.5 ±0.05
1.65 ±0.05
2.10 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ±0.05
0.50
BSC
2.38 ±0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
3.00 ±0.10
(4 SIDES)
R = 0.125
TYP
5
0.40 ±0.10
8
1.65 ±0.10
(2 SIDES)
0.75 ±0.05
4
0.25 ±0.05
1
(DD8) DFN 0509 REV C
0.50 BSC
2.38 ±0.10
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
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
60201fa
16
For more information www.linear.com/LT6020
LT6020/LT6020-1
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
DD Package
10-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1699 Rev C)
0.70 ±0.05
3.55 ±0.05
1.65 ±0.05
2.15 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ±0.05
0.50
BSC
2.38 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
3.00 ±0.10
(4 SIDES)
R = 0.125
TYP
6
0.40 ±0.10
10
1.65 ±0.10
(2 SIDES)
PIN 1 NOTCH
R = 0.20 OR
0.35 × 45°
CHAMFER
PIN 1
TOP MARK
(SEE NOTE 6)
0.200 REF
0.75 ±0.05
0.00 – 0.05
5
1
(DD) DFN REV C 0310
0.25 ±0.05
0.50 BSC
2.38 ±0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).
CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT
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 THE
TOP AND BOTTOM OF PACKAGE
60201fa
For more information www.linear.com/LT6020
17
LT6020/LT6020-1
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev G)
0.889 ±0.127
(.035 ±.005)
5.10
(.201)
MIN
3.20 – 3.45
(.126 – .136)
3.00 ±0.102
(.118 ±.004)
(NOTE 3)
0.65
(.0256)
BSC
0.42 ± 0.038
(.0165 ±.0015)
TYP
8
7 6 5
0.52
(.0205)
REF
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
4.90 ±0.152
(.193 ±.006)
DETAIL “A”
0° – 6° TYP
GAUGE PLANE
0.53 ±0.152
(.021 ±.006)
DETAIL “A”
1
2 3
4
1.10
(.043)
MAX
0.86
(.034)
REF
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.65
(.0256)
BSC
0.1016 ±0.0508
(.004 ±.002)
MSOP (MS8) 0213 REV G
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
60201fa
18
For more information www.linear.com/LT6020
LT6020/LT6020-1
Revision History
REV
DATE
DESCRIPTION
A
04/14
Added MS8 package version.
PAGE NUMBER
All
60201fa
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.
For more
information
www.linear.com/LT6020
19
LT6020/LT6020-1
Typical Application
Gain of 11 Instrumentation Amplifier
VINM
R3, 10k
R2, 10k
–
–
1/2 LT6020
1/2 LT6020
+
V+
R1, 100k
VIN
VOUT
+
R1 TO R4: FOR HIGH DC CMRR USE LT5400-3
1/2 LTC203
IN1
0
1k
VOUT
LT6020
2N3906
V–
60201 F03a
±13.6V Input Range MUX Buffer
5
–
–3dB BW = 30kHz
VINP
2N3904
+
LOAD
R4, 100k
Improved Load Drive Capability
60201 F03b
MUX Buffer Response, 12V Step
15V
V+
IN2
15V
VIN1
–6V
S1
D1
VIN2
6V
S2
D2
GND
V–
+
1/2 LT6020
–
15V
–15V
60201 TA03c
Related Parts
PART NUMBER
DESCRIPTION
COMMENTS
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6.5MHz, 65µA RRIO Op Amp
VOS: 350µV, GBW: 6.5MHz, SR: 1.8V/µs, en: 20nV/√Hz, IS: 65µA
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3MHz. 200V/µs Op Amp
VOS: 600µV, GBW: 3MHz, SR: 200V/µs, en: 14nV/√Hz, IS: 330µA
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5MHz, 3V/µs Op Amp
VOS: 180µV, GBW: 5MHz, SR: 3V/µs, en: 16.5nV/√Hz, IS: 550µA
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Wireless Mesh Networks
LT5400
Quad Matched Resistor Network
0.01% Matching
60201fa
20 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
For more information www.linear.com/LT6020
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com/LT6020
LT0414 REV A • PRINTED IN USA
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