Product
Folder
Order
Now
Support &
Community
Tools &
Software
Technical
Documents
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
OPAx320-Q1 Precision, 20-MHz, 0.9-pA, Low-Noise, RRIO,
CMOS Operational Amplifier
1 Features
3 Description
•
•
The OPA320-Q1 and OPA2320-Q1 (OPAx320-Q1)
devices are a new generation of precision low-voltage
CMOS operational amplifiers (op amps) optimized for
very low noise and wide bandwidth. These devices
operate on a low quiescent current of only 1.45 mA.
1
•
•
•
•
•
•
•
•
•
Qualified for Automotive Applications
AEC-Q100 Qualified with the Following Results:
– Device Temperature Grade 1: –40°C to 125°C
Ambient Operating Temperature Range
– Device HBM ESD Classification Level 2
– Device CDM ESD Classification Level C4B
Precision with Zero-Crossover Distortion:
– Low Offset Voltage: 150 µV (max)
– High CMRR: 114 dB
– Rail-to-Rail I/O
Low Input Bias Current: 0.9 pA (max)
Low Noise: 7 nV/√Hz at 10kHz
Wide Bandwidth: 20 MHz
Slew Rate: 10 V/µs
Quiescent Current: 1.45 mA/ch
Single-Supply Voltage Range: 1.8 to 5.5 V
Unity-Gain Stable
Small VSSOP Package
2 Applications
•
•
•
•
•
•
•
•
•
Automotive
High-Z Sensor Signal Conditioning
Transimpedance Amplifiers
Test and Measurement Equipment
Programmable Logic Controllers (PLCs)
Motor Control Loops
Communications
Input and Output ADC and DAC Buffers
Active Filters
The OPAx320-Q1 are an excellent choice for lowpower, single-supply applications. Low-noise (7
nV/√Hz) and high-speed operation also makes these
devices an excellent choice for driving sampling
analog-to-digital
converters
(ADCs).
Other
applications include signal conditioning and sensor
amplification.
The OPAx320-Q1 feature a linear input stage with
zero-crossover distortion that delivers excellent
common-mode rejection ratio (CMRR) of 114 dB
(typical) over the full input range. The input commonmode range extends 100 mV beyond the negative
and positive supply rails. The output voltage typically
swings within 10 mV of the rails.
In addition, the OPAx320-Q1 have a wide supply
voltage range from 1.8 V to 5.5 V, with excellent
PSRR (106 dB) over the entire supply range. These
features make the OPAx320-Q1 suitable for
precision, low-power applications that run directly
from batteries without regulation.
The OPAx320-Q1 device is available in an 8-pin
VSSOP (DGK) package.
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
OPA320-Q1
SOT (5)
2.90 mm x 1.60 mm
OPA2320-Q1
VSSOP (8)
3.00 mm × 3.00 mm
(1) For all available packages, see the package option addendum
at the end of the datasheet.
Zero Crossover Distortion: Low Offset Voltage
100
80
Offset Voltage (µV)
60
40
20
0
–20
–40
–60
–80
–100
–3 –2.5 –2 –1.5 –1 –0.5 0
0.5
1
1.5
2
2.5
3
Common-Mode Voltage (V)
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
4
4
4
4
5
7
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics: ........................................
Typical Characteristics ..............................................
Detailed Description ............................................ 12
7.1
7.2
7.3
7.4
Overview .................................................................
Functional Block Diagram .......................................
Feature Description.................................................
Device Functional Modes........................................
12
12
13
16
8
Application and Implementation ........................ 17
8.1 Application Information............................................ 17
8.2 Typical Applications ................................................ 17
9 Power Supply Recommendations...................... 22
10 Layout................................................................... 22
10.1 Layout Guidelines ................................................. 22
10.2 Layout Example .................................................... 23
11 Device and Documentation Support ................. 24
11.1
11.2
11.3
11.4
11.5
11.6
11.7
Device Support......................................................
Related Links ........................................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
24
24
24
24
24
24
25
12 Mechanical, Packaging, and Orderable
Information ........................................................... 25
4 Revision History
Changes from Revision A (December 2016) to Revision B
Page
•
Changed Figure 1 x-axis unit from mV to µV (typo) ............................................................................................................... 7
•
Changed Figure 2 x-axis unit from mV/°C to µV/°C (typo)..................................................................................................... 7
•
Changed Figure 3 y-axis unit from mV to µV (typo) ............................................................................................................... 7
•
Changed Figure 14 y-axis unit from mV to µV (typo) ............................................................................................................. 8
•
Changed Figure 19 y-axis unit from W to Ω (typo)................................................................................................................. 9
•
Changed Figure 25 y-axis unit from V/ms to V/µs (typo) ..................................................................................................... 10
•
Changed Figure 26 x-axis unit from ms to µs (typo) ............................................................................................................ 10
•
Changed Figure 27 x-axis unit from ms to µs (typo) ............................................................................................................ 10
•
Changed Figure 28 x-axis unit from ms to µs (typo) ............................................................................................................ 10
•
Changed Figure 35 x-axis unit from ms to µs (typo) ............................................................................................................ 16
Changes from Original (September 2014) to Revision A
Page
•
Added OPA320-Q1 device to document ................................................................................................................................ 1
•
Changed OPA2320-Q1 to OPAx320-Q1 throughout document where both devices are being referred to .......................... 1
•
Changed first sentence of Description section: added (OPA320-Q1, OPA2320-Q1) ............................................................ 1
•
Added OPA320-Q1 to Device Information table..................................................................................................................... 1
•
Added OPA320-Q1 device (SOT package) to Pin Configuration and Functions section: added OPA320-Q1 pin out
to section and added relevant rows to Pin Functions table.................................................................................................... 3
•
Changed format of ESD Ratings table: updated table to current standards, moved storage temperature parameter to
Absolute Maximum Ratings table ........................................................................................................................................... 4
•
Changed Supply voltage parameter in Recommended Operating Conditions table: split apart single- and dualsupply values into separate rows ........................................................................................................................................... 4
•
Added OPA320-Q1 package to Thermal Information table ................................................................................................... 4
•
Changed Output Voltage Swing vs Output Current figure ..................................................................................................... 8
•
Changed Operational Amplifier Board Layout for Noninverting Configuration figure........................................................... 23
2
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
5 Pin Configuration and Functions
OPA320-Q1: DBV Package
5-Pin SOT
Top View
OPA2320-Q1: DGK Package
8-Pin VSSOP
Top View
Pin Functions
PIN
NAME
NO.
I/O
DESCRIPTION
DBV
DGK
–IN
4
—
I
Inverting input
–IN A
—
2
I
Inverting input (channel A)
–IN B
—
6
I
Inverting input (channel B)
+IN
3
—
I
Noninverting input
+IN A
—
3
I
Noninverting input (channel A)
+IN B
—
5
I
Noninverting input (channel B)
OUT
1
—
O
Output
OUT A
—
1
O
Output (channel A)
OUT B
—
7
O
Output (channel B)
V–
2
4
—
Negative supply or ground (for single-supply operation)
V+
5
8
—
Positive supply
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
3
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
Supply voltage
Voltage
(2)
Current (2)
(3)
V
V(V–) – 0.5
V(V+) + 0.5
–10
10
mA
Continuous
–40
150
Junction, TJ
150
Storage, Tstg
(2)
V
Signal input pins
Operating, TA
(1)
UNIT
6
Signal input pins
Output short-circuit current (3)
Temperature
MAX
V+ and V–
–65
°C
150
Stresses beyond those listed as absolute maximum ratings may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated as recommended operating conditions is
not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.5 V beyond the supply rails should
be current limited to 10 mA or less.
Short-circuit to ground, one amplifier per package.
6.2 ESD Ratings
VALUE
Human-body model (HBM), per AEC Q100-002 (1)
V(ESD)
(1)
Electrostatic discharge
Charged-device model (CDM),
per AEC Q100-011
UNIT
±2000
All pins
±500
Corner pins (1, 4, 5, and 8)
±750
V
AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
Single-supply
VS
Supply voltage
TA
Ambient operating temperature
Dual-supply
NOM
MAX
1.8
5.5
±0.9
±2.75
–40
125
UNIT
V
°C
6.4 Thermal Information
THERMAL METRIC
(1)
OPA320-Q1
OPA2320-Q1
DBV (SOT)
DGK (VSSOP)
5 PINS
8 PINS
UNIT
RθJA
Junction-to-ambient thermal resistance
158.8
174.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
60.7
43.9
°C/W
RθJB
Junction-to-board thermal resistance
44.8
95
°C/W
ψJT
Junction-to-top characterization parameter
1.6
2
°C/W
ψJB
Junction-to-board characterization parameter
4.2
93.5
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
—
—
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
6.5
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
Electrical Characteristics:
VS = 1.8 to 5.5 V or ±0.9 V to ±2.75 V; at TA = 25°C, R(L) = 10 kΩ connected to VS / 2, V(CM) = VS / 2, VO = VS / 2 (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
40
150
µV
1.5
5
5
20
OFFSET VOLTAGE
VIO
Input offset voltage
Input offset voltage versus
temperature
Input offset voltage versus power
supply
Input offset-voltage channel
separation
VS = 5.5 V, TA = –40°C to +125°C
VS = 1.8 to 5.5 V
VS = 1.8 to 5.5 V, TA = –40°C to +125°C
15
At 1 kHz
130
µV/°C
µV/V
dB
INPUT VOLTAGE
V(CM)
Common-mode voltage range
CMRR
Common-mode rejection ratio
VS = 5.5 V, V(V–) – 0.1 V < V(CM) < V(V+) + 0.1 V
V(V–) – 0.1
100
Common-mode rejection ratio,
over temperature
VS = 5.5 V, V(V–) – 0.1 V < V(CM) < V(V+) + 0.1 V,
TA = –40°C to 125°C
96
V(V+) + 0.1
114
V
dB
dB
INPUT BIAS CURRENT
IIB
Input bias current
Input bias current, over
temperature
IIO
±0.2
±0.9
TA = –40°C to 85°C
±50
TA = –40°C to 125°C
±400
Input offset current
±0.2
±0.9
Input offset current, over
temperature
TA = –40°C to 85°C
±50
TA = –40°C to 125°C
±400
Input voltage noise
f = 0.1 to 10 Hz
2.8
f = 1 kHz
8.5
pA
pA
pA
pA
NOISE
VI(n)
Input voltage noise density
Input current noise density
f = 10 kHz
7
f = 1 kHz
0.6
µVPP
nV/√Hz
fA/√Hz
INPUT CAPACITANCE
Differential
5
pF
Common-mode
4
pF
OPEN-LOOP GAIN
A(OL)
Open-loop voltage gain
PM
Phase margin
0.1 V < VO < V(V+) – 0.1 V, R(L) = 10 kΩ
114
132
0.1 V < VO < V(V+) – 0.1 V, R(L) = 10 kΩ, TA = –40°C to 125°C
100
130
0.2 V < VO < V(V+) – 0.2 V, R(L) = 2 kΩ
108
123
96
130
0.2 V < VO < V(V+) – 0.2 V, R(L) = 2 kΩ, TA = –40°C to 125°C
VS = 5 V, C(L) = 50 pF
dB
47
°
FREQUENCY RESPONSE (VS = 5 V, C(L) = 50 pF)
GBP
Gain bandwidth product
Unity gain
20
MHz
SR
Slew rate
G=1
10
V/µs
ts
Settling time
To 0.1%, 2-V step, G = 1
0.25
To 0.01%, 2-V step, G = 1
0.32
To 0.0015%, 2-V step, G = 1 (1)
THD+N
(1)
(2)
µs
0.5
Overload recovery time
VI × G > VS
Total harmonic distortion +
noise (2)
VO = 4 VPP, G = 1, f = 10 kHz, R(L) = 10 kΩ
0.0005%
100
VO = 4 VPP, G = 1, f = 10 kHz, R(L) = 600 kΩ
0.0011%
ns
Based on simulation.
Third-order filter; bandwidth = 80 kHz at –3 dB.
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
5
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
Electrical Characteristics: (continued)
VS = 1.8 to 5.5 V or ±0.9 V to ±2.75 V; at TA = 25°C, R(L) = 10 kΩ connected to VS / 2, V(CM) = VS / 2, VO = VS / 2 (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
OUTPUT
R(L) = 10 kΩ
VO
Voltage output swing from both
rails
I(SC)
Short-circuit current
C(L)
Capacitive load drive
10
R(L) = 10 kΩ, TA = –40°C to 125°C
30
R(L) = 2 kΩ
25
R(L) = 2 kΩ, TA = –40°C to 125°C
Open-loop output resistance
20
35
mV
45
VS = 5.5 V
±65
mA
See Typical Characteristics
IO = 0 mA, f = 1MHz
90
Ω
POWER SUPPLY
VS
IQ
Specified voltage range
Quiescent current per amplifier
Power-on time
1.8
IO = 0 mA, VS = 5.5V
5.5
1.45
IO = 0 mA, VS = 5.5V, TA = –40°C to 125°C
1.6
1.7
V(V+) = 0 to 5 V, to 90% IQ level
28
V
mA
µs
TEMPERATURE
6
Specified range
–40
125
°C
Operating range
–40
150
°C
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
6.6 Typical Characteristics
at TA = 25°C, V(CM) = VO = mid-supply, and R(L) = 10 kΩ (unless otherwise noted)
14
25
20
Number of Amplifiers
Number of Amplifiers (%)
12
10
8
6
4
15
10
5
2
0
0
0.5
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0.1
0.9
1.3
1.7
2.1
2.5
2.9
Offset Drift (µV/°C)
Offset Voltage (µV)
Figure 2. Offset Voltage Drift Distribution
100
160
80
140
60
120
-40
100
-60
80
-80
60
-100
40
-120
–60
20
-140
–80
0
-160
Gain (dB)
40
20
0
–20
–40
Phase
Gain
-20
–100
–3 –2.5 –2 –1.5 –1 –0.5 0
0.5
1
1.5
2
10
1
3
2.5
100
1k
Common-Mode Voltage (V)
10M
Figure 4. Open-Loop Gain and Phase vs Frequency
10-kΩ Load
2-kΩ Load
130
125
120
115
110
1.45
1.4
1.35
125°C
85°C
25°C
–40°C
1.3
105
100
1.25
-50
-25
0
25
50
75
100
-180
100M
1.5
Quiescent Current (mA/Ch)
Open-Loop Gain (dB)
1M
VS = ±2.5 V, C(L) = 50 pF
Figure 3. Offset Voltage vs Common-Mode Voltage
135
100k
-20
Frequency (Hz)
Representative units, VS = ±2.75 V
140
10k
0
Phase (°)
Offset Voltage (µV)
Figure 1. Offset Voltage Production Distribution
125
150
1.5
2
Figure 5. Open-Loop Gain vs Temperature
2.5
3
3.5
4
4.5
5
5.5
Supply Voltage (V)
Temperature (°C)
Figure 6. Quiescent Current vs Supply Voltage
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
7
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
Typical Characteristics (continued)
at TA = 25°C, V(CM) = VO = mid-supply, and R(L) = 10 kΩ (unless otherwise noted)
1
0.6
0.4
0.2
0
-0.2
-0.4
IIB+
IIB–
IIO
5
4
Input Bias Current (pA)
Input Bias Current (pA)
6
IIB–
IIB+
0.8
-0.6
3
2
1
0
-1
-2
-3
-4
-0.8
-5
-1
-6
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
2.7
-3 -2.5 -2 -1.5 -1 -0.5
2.9
Figure 7. Input Bias Current vs Supply Voltage
35
30
Input Bias Current (pA)
Number of Amplifiers (%)
25
20
15
10
5
0.2
0.25
0.1
0.15
0
0.05
-0.1
-0.05
-0.15
-0.2
-0.3
-0.25
0
-0.35
0.5
1
1.5
2
2.5
3
Figure 8. Input Bias Current vs Common-Mode Voltage
40
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
-100
IIB–
IIB+
IIO
IIB
-50
-25
0
25
50
75
100
IIO
125
150
Temperature (°C)
Input Bias Current (pA)
Figure 10. Input Bias Current vs Temperature
Figure 9. Input Bias Current Distribution
PSRR
CMRR
120
100
80
60
40
20
0
130
Common-Mode Rejection Ratio (dB),
Power-Supply Rejection Ratio (dB)
140
Common-Mode Rejection Ratio (dB),
Power-Supply Rejection Ratio (dB)
0
Common-Mode Voltage (V)
Supply Voltage (±V)
PSRR
125
CMRR
120
115
110
105
100
95
90
100
1k
10k
100k
1M
10M
-50
-25
Frequency (Hz)
0
25
50
75
100
125
150
Temperature (°C)
VS = 1.8 to 5.5 V
Figure 11. CMRR and PSRR vs Frequency
8
Submit Documentation Feedback
Figure 12. CMRR and PSRR vs Temperature
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
Typical Characteristics (continued)
at TA = 25°C, V(CM) = VO = mid-supply, and R(L) = 10 kΩ (unless otherwise noted)
6
1000
4
3
100
Voltage (µV)
Voltage Noise (nV/ √ Hz)
5
10
2
1
0
–1
–2
–3
1
–4
10
100
1k
10k
0
1M
100k
1
2
3
4
5
6
7
8
10
9
Time (1 s/div)
Frequency (Hz)
VS = 1.8 to 5.5 V
Figure 13. Input Voltage Noise Spectral Density vs
Frequency
60
60
G = 100 V/V
G = 10 V/V
G = 1 V/V
G = 100 V/V
G = 10 V/V
G = 1 V/V
40
Gain (dB)
40
Gain (dB)
Figure 14. 0.1-Hz to 10-Hz Input Voltage Noise
20
0
20
0
-20
-20
10k
100k
1M
10k
100M
10M
100k
Frequency (Hz)
VS = 1.8 V, C(L) = 50 pF, R(L) = 10 kΩ
100M
10M
VS = 5.5 V, C(L) = 50 pF, R(L) = 10 kΩ
Figure 15. Closed-Loop Gain vs Frequency
6
Figure 16. Closed-Loop Gain vs Frequency
3
5.5 VS
3.3 VS
5
4
3
2
–40°C
25°C
125°C
2
1.8 VS
Output Voltage (V)
Output Voltage (VPP)
1M
Frequency (Hz)
1
0
-1
-2
1
-3
0
10k
100k
1M
10M
0
10
20
30
40
50
60
70
80
Output Current (mA)
Frequency (Hz)
C(L) = 50 pF, R(L) = 10 kΩ
Figure 17. Maximum Output Voltage vs Frequency
VS = ±2.75 V
Figure 18. Output Voltage Swing vs Output Current
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
9
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
Typical Characteristics (continued)
at TA = 25°C, V(CM) = VO = mid-supply, and R(L) = 10 kΩ (unless otherwise noted)
70
1000
G = 1 V/V, VS = 1.8 V
G = 1 V/V, VS = 5.5 V
G = 10 V/V, VS = 1.8 V
50
Overshoot (%)
Impedance (Ω)
60
100
G = 10 V/V, VS = 5.5 V
40
30
20
10
0
10
1
10
100
1k
10k
100k
1M
10M
500
0
100M
1000
1500
2000
2500
3000
Capacitive Load (pF)
Frequency (Hz)
VS = ±2.75 V
0.1
0.01
0.001
Load = 600 Ω
Load = 10 kΩ
0.0001
0.01
Figure 20. Small-Signal Overshoot vs Load Capacitance
Total Harmonic Distortion and Noise (%)
Total Harmonic Distortion and Noise (%)
Figure 19. Open-Loop Output Impedance vs Frequency
0.1
10
1
0.1
Load = 600 Ω
Load = 10 kΩ
0.01
0.001
0.0001
10
100
Input Voltage (VPP)
VS = ±2.5 V, f = 10 kHz, G = 1 V/V
Figure 22. THD+N vs Frequency
Load = 600 Ω
Load = 10 kΩ
-20
Channel Separation (dB)
Total Harmonic Distortion and Noise (%)
100k
0
0.01
0.001
-40
-60
-80
-100
-120
0.0001
-140
10
100
1k
10k
100k
1k
10k
Frequency (Hz)
Figure 23. THD+N vs Frequency
Submit Documentation Feedback
100k
1M
10M
100M
Frequency (Hz)
VS = ±2.5 V, f = 10 kHz, G = 1 V/V, VI = 4 VPP
10
10k
VS = ±2.5 V, f = 10 kHz, G = 1 V/V, VI = 2 VPP
Figure 21. THD+N vs Amplitude
0.1
1k
Frequency (Hz)
VS = ±2.75 V
Figure 24. Channel Separation vs Frequency
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
Typical Characteristics (continued)
at TA = 25°C, V(CM) = VO = mid-supply, and R(L) = 10 kΩ (unless otherwise noted)
12
0.1
Rise
Fall
VO
VI
0.075
11.5
Voltage (V)
Slew Rate (V/µs)
0.05
11
10.5
10
0.025
0
–0.025
–0.05
9.5
–0.075
9
1.6
2
2.4
2.8
3.2
3.6
4
4.4
4.8
5.2
–0.1
–0.8
5.6
–0.4
0
0.4
0.8
1.6
1.2
Time (µs)
Supply Voltage (V)
C(L) = 50 pF
VS = ±2.75 V, G = 1 V/V, VI = 100 mVPP
Figure 25. Slew Rate vs Supply Voltage
0.1
Figure 26. Small-Signal Step Response
1.5
VO
VI
0.075
VI
VO
1
0.025
Voltage (V)
Voltage (V)
0.05
0
–0.025
0.5
0
–0.5
–0.05
–1
–0.075
–0.1
–1.6
–1.2
–0.8
–0.4
0
0.4
0.8
–1.5
–0.4
0
0.4
0.8
1.2
1.6
Time (µs)
Time (µs)
VS = ±2.75 V, G = –1 V/V, VI = 100 mVPP
Figure 27. Small-Signal Step Response
VS = ±2.75 V, G = 1 V/V, VI = 2 VPP
Figure 28. Large-Signal Step Response vs Time
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
11
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
7 Detailed Description
7.1 Overview
The OPA320-Q1 and OPA2320-Q1 (OPAx320-Q1) operational amplifiers (op amps) are unity-gain stable and
operate on a single-supply voltage (1.8 V to 5.5 V), or a split supply voltage (±0.9 V to ±2.75 V), making these
devices highly versatile and easy to use. The OPAx320-Q1 amplifiers are fully specified from 1.8 V to 5.5 V and
over the extended temperature range of –40°C to +125°C. Parameters that can exhibit variance with regard to
operating voltage or temperature are presented in the Typical Characteristics section.
7.2 Functional Block Diagram
V(V+)
Charge Pump
Reference
Current
IN+
IN±
VBIAS1
Class AB
Control
Circuitry
OUT
VBIAS2
E-TrimTM
V(V-)
12
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
7.3 Feature Description
7.3.1 Input and ESD Protection
The OPAx320-Q1 incorporate internal electrostatic discharge (ESD) protection circuits on all pins. In the case of
input and output pins, this protection primarily consists of current-steering diodes connected between the input
and power-supply pins. These ESD protection diodes also provide in-circuit input overdrive protection, provided
that the current is limited to 10 mA, as stated in the Absolute Maximum Ratings. Many input signals are
inherently current-limited to less than 10 mA; therefore, a limiting resistor is not required. Figure 29 shows how a
series input resistor (R(S)) may be added to the driven input to limit the input current. The added resistor
contributes thermal noise at the amplifier input and the value should be kept to the minimum in noise-sensitive
applications.
V(V+)
I(OVERLOAD)
10 mA, Max
OPA320-Q1
VO
VI
R(S)
Figure 29. Input Current Protection
7.3.2 Feedback Capacitor Improves Response
For optimum settling time and stability with high-impedance feedback networks, adding a feedback capacitor
across the feedback resistor, R(FB), as shown in Figure 30 may be necessary. This capacitor compensates for the
zero created by the feedback network impedance and the OPAx320-Q1 input capacitance (and any parasitic
layout capacitance). The effect becomes more significant with higher impedance networks.
C(F)
R(IN)
R(F)
VI
V(V+)
C(IN)
R(IN) × C(IN) = R(F) × C(F)
OPA320-Q1
VO
C(L)
C(IN)
NOTE: Where C(IN) is equal to the OPAx320-Q1 input capacitance (approximately 9 pF) plus any parasitic layout
capacitance.
Figure 30. Feedback Capacitor Improves Dynamic Performance
It is suggested that a variable capacitor be used for the feedback capacitor because input capacitance may vary
between op amps and layout capacitance is difficult to determine. For the circuit shown in Figure 30, the value of
the variable feedback capacitor should be chosen so that the input resistance times the input capacitance of the
OPAx320-Q1 (9 pF, typical) plus the estimated parasitic layout capacitance equals the feedback capacitor times
the feedback resistor:
R(IN) × C(IN) = R(FB) × C(FB)
Where:
•
C(IN) is equal to the OPAx320-Q1 input capacitance (sum of differential and common-mode) plus the layout
capacitance.
(1)
The capacitor value can be adjusted until optimum performance is obtained.
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
13
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
Feature Description (continued)
7.3.3 EMI Susceptibility And Input Filtering
Operational amplifiers vary in susceptibility to electromagnetic interference (EMI). If conducted EMI enters the
operational amplifier, the DC offset observed at the amplifier output may shift from the nominal value while EMI is
present. This shift is a result of signal rectification associated with the internal semiconductor junctions. While all
operational amplifier pin functions can be affected by EMI, the input pins are likely to be the most susceptible.
The OPAx320-Q1 operational amplifier family incorporates an internal input low-pass filter that reduces the
amplifiers response to EMI. Both common-mode and differential mode filtering are provided by the input filter.
The filter is designed for a cut-off frequency of approximately 580 MHz (–3 dB), with a roll-off of 20 dB per
decade.
7.3.4 Output Impedance
The open-loop output impedance of the OPAx320-Q1 common-source output stage is approximately 90 Ω. When
the op amp is connected with feedback, this value is reduced significantly by the loop gain. For example, with
130 dB (typical) of open-loop gain, the output impedance is reduced in unity-gain to less than 0.03 Ω. For each
decade rise in the closed-loop gain, the loop gain is reduced by the same amount, which results in a ten-fold
increase in effective output impedance. While the OPAx320-Q1 output impedance remains very flat over a wide
frequency range, at higher frequencies the output impedance rises as the open-loop gain of the op amp drops.
However, at these frequencies the output also becomes capacitive as a result of parasitic capacitance. This in
turn prevents the output impedance from becoming too high, which can cause stability problems when driving
large capacitive loads. As mentioned previously, the OPAx320-Q1 have excellent capacitive load drive capability
for op amps with the bandwidth.
7.3.5 Capacitive Load and Stability
The OPAx320-Q1 are designed to be used in applications where driving a capacitive load is required. As with all
op amps, there may be specific instances where the OPAx320-Q1 can become unstable. The particular op amp
circuit configuration, layout, gain, and output loading are some of the factors to consider when establishing
whether an amplifier is stable in operation. An op amp in the unity-gain (1 V/V) buffer configuration and driving a
capacitive load exhibits a greater tendency to become unstable than an amplifier operated at a higher noise gain.
The capacitive load, in conjunction with the op amp output resistance, creates a pole within the feedback loop
that degrades the phase margin. The degradation of the phase margin increases as the capacitive loading
increases. When operating in the unity-gain configuration, the OPAx320-Q1 remain stable with a pure capacitive
load up to approximately 1 nF.
The equivalent series resistance (ESR) of some very large capacitors (C(L) > 1 µF) is sufficient to alter the phase
characteristics in the feedback loop such that the amplifier remains stable. Increasing the amplifier closed-loop
gain allows the amplifier to drive increasingly larger capacitance. This increased capability is evident when
observing the overshoot response of the amplifier at higher voltage gains; see Figure 32. One technique for
increasing the capacitive load drive capability of the amplifier operating in unity gain is to insert a small resistor
(R(S)), typically 10 Ω to 20 Ω, in series with the output, as shown in Figure 31.
This resistor significantly reduces the overshoot and ringing associated with large capacitive loads. A possible
problem with this technique is that a voltage divider is created with the added series resistor and any resistor
connected in parallel with the capacitive load. The voltage divider introduces a gain error at the output that
reduces the output swing. The error contributed by the voltage divider may be insignificant. For instance, with a
load resistance, R(L) = 10 kΩ and R(S) = 20 Ω, the gain error is only about 0.2%. However, when R(L) is
decreased to 600 Ω, which the OPAx320-Q1 are able to drive, the error increases to 7.5%.
V(V+)
R(S)
VO
OPA320-Q1
VI
10 Ω to
20 Ω
R(L)
C(L)
Figure 31. Improving Capacitive Load Drive
14
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
Feature Description (continued)
70
G = 1 V/V, VS = 1.8 V
G = 1 V/V, VS = 5.5 V
60
G = 10 V/V, VS = 1.8 V
Overshoot (%)
50
G = 10 V/V, VS = 5.5 V
40
30
20
10
0
0
500
1000
1500
2000
3000
2500
Capacitive Load (pF)
Figure 32. Small-Signal Overshoot versus Capacitive Load (100-mVPP Output Step)
7.3.6 Overload Recovery Time
Overload recovery time is the time it takes the output of the amplifier to come out of saturation and recover to the
linear region. Overload recovery is particularly important in applications where small signals must be amplified in
the presence of large transients. Figure 33 and Figure 34 show the positive and negative overload recovery
times of the OPAx320-Q1, respectively. In both cases, the time elapsed before the OPAx320-Q1 come out of
saturation is less than 100 ns. In addition, the symmetry between the positive and negative recovery times allows
excellent signal rectification without distortion of the output signal.
3
2.5
2
0
1.5
-0.5
1
0.5
-1.5
-2
-0.5
-2.5
10
10.25
10.5
10.75
11
Output
-1
0
-1
9.75
Input
0.5
Output
Voltage (V)
Voltage (V)
1
Input
-3
9.75
10
Time (250 ns/div)
VS = ±2.75 V, G = –10 V/V
Figure 33. Positive Recovery Time
10.25
10.5
10.75
11
Time (250 ns/div)
VS = ±2.75 V, G = –10 V/V
Figure 34. Negative Recovery Time
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
15
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
7.4 Device Functional Modes
7.4.1 Rail-to-Rail Input
The OPAx320-Q1 feature true rail-to-rail input operation, with supply voltages as low as ±0.9 V (1.8 V). The
design of the OPAx320-Q1 amplifiers include an internal charge-pump that powers the amplifier input stage with
an internal supply rail at approximately 1.6 V above the external supply (V+). This internal supply rail allows the
single differential input pair to operate and remain very linear over a very wide input common-mode range. A
unique zero-crossover input topology eliminates the input offset transition region typical of many rail-to-rail,
complementary input stage operational amplifiers. This topology allows the OPAx320-Q1 to provide superior
common-mode performance (CMRR > 110 dB, typical) over the entire common-mode input range, which extends
100 mV beyond both power-supply rails. When driving analog-to-digital converters (ADCs), the highly linear V(CM)
range of the OPAx320-Q1 provides maximum linearity and lowest distortion.
7.4.2 Phase Reversal
The OPAx320-Q1 op amps are designed to be immune to phase reversal when the input pins exceed the supply
voltages, and thus provide further in-system stability and predictability. Figure 35 shows the input voltage
exceeding the supply voltage without any phase reversal.
4
VI
VO
3
Voltage (V)
2
1
0
–1
–2
–3
–4
–500
–250
0
250
500
750
1000
Time (µs)
VS = ±2.5 V
Figure 35. No Phase Reversal
16
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The OPAx320-Q1 can be used in a wide range of applications, such as transimpedance amplifiers, highimpedance sensors, active filters, and driving ADCs.
8.2 Typical Applications
8.2.1 Transimpedance Amplifier
Wide gain bandwidth, low input bias current, low input voltage, and current noise make the OPAx320-Q1 an
excellent wideband photodiode transimpedance amplifier. Low-voltage noise is important because photodiode
capacitance causes the effective noise gain of the circuit to increase at high frequency.
The key elements to a transimpedance design, as shown in Figure 36, are the expected diode capacitance
(C(D)), which should include the parasitic input common-mode and differential-mode input capacitance (4 pF + 5
pF); the desired transimpedance gain (R(FB)); and the gain-bandwidth (GBW) for the OPAx320-Q1 (20 MHz).
With these three variables set, the feedback capacitor value (C(FB)) can be set to control the frequency response.
C(FB) includes the stray capacitance of R(FB), which is 0.2 pF for a typical surface-mount resistor.
(1)
C(F)
< 1 pF
R(F)
10 MΩ
V(V+)
l
C(D)
OPA320-Q1
VO
V(V–)
(1) C(FB) is optional to prevent gain peaking. C(FB) includes the stray capacitance of R(FB).
Figure 36. Dual-Supply Transimpedance Amplifier
8.2.1.1 Design Requirements
PARAMETER
VALUE
Supply voltage V(V+)
2.5 V
Supply voltage V(V–)
–2.5 V
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
17
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
8.2.1.2 Detailed Design Procedure
To achieve a maximally-flat, second-order Butterworth frequency response, the feedback pole should be set to:
1
=
2 ´ p ´ R(FB) ´ C(FB)
GBW
4 ´ p ´ R(FB) ´ C(D)
(2)
Use Equation 3 to calculate the bandwidth.
ƒ(–3 dB) =
GBW
2 ´ p ´ R(FB) ´ C(D)
(3)
For even higher transimpedance bandwidth, consider the high-speed CMOS OPA380 (90-MHz GBW), OPA354
(100-MHz GBW), OPA300 (180-MHz GBW), OPA355 (200-MHz GBW), and OPA656 or OPA657 (400-MHz
GBW).
For single-supply applications, the +INx input can be biased with a positive dc voltage to allow the output to
reach true zero when the photodiode is not exposed to any light, and respond without the added delay that
results from coming out of the negative rail; this configuration is shown in Figure 37. This bias voltage also
appears across the photodiode, providing a reverse bias for faster operation.
(1)
C(FB)
< 1pF
R(FB)
10 MΩ
V(V+)
l
VO
OPA320-Q1
+V(BIAS)
(1) C(FB) is optional to prevent gain peaking. C(FB) includes the stray capacitance of R(FB).
Figure 37. Single-Supply Transimpedance Amplifier
For additional information, refer to the Compensate Transimpedance Amplifiers Intuitively Application Report.
8.2.1.2.1 Optimizing The Transimpedance Circuit
To achieve the best performance, components should be selected according to the following guidelines:
1. For lowest noise, select R(FB) to create the total required gain. Using a lower value for R(FB) and adding gain
after the transimpedance amplifier generally produces poorer noise performance. The noise produced by
R(FB) increases with the square-root of R(FB), whereas the signal increases linearly. Therefore, signal-to-noise
ratio improves when all the required gain is placed in the transimpedance stage.
2. Minimize photodiode capacitance and stray capacitance at the summing junction (inverting input). This
capacitance causes the voltage noise of the op amp to be amplified (increasing amplification at high
frequency). Using a low-noise voltage source to reverse-bias a photodiode can significantly reduce the
capacitance. Smaller photodiodes have lower capacitance. Use optics to concentrate light on a small
photodiode.
3. Noise increases with increased bandwidth. Limit the circuit bandwidth to only that required. Use a capacitor
across the R(FB) to limit bandwidth, even if not required for stability.
18
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
4. Circuit board leakage can degrade the performance of an otherwise well-designed amplifier. Clean the circuit
board carefully. A circuit board guard trace that encircles the summing junction and is driven at the same
voltage can help control leakage.
For additional information, refer to the following documents:
• Texas Instruments, Noise Analysis of FET Transimpedance Amplifiers Application Bulletin
• Texas Instruments, Noise Analysis for High-Speed Op Amps Application Report
8.2.1.3 Application Curves
Wide gain bandwidth as shown in Figure 38 and low input voltage noise as shown in Figure 39 make the
OPAx320-Q1 device an excellent wideband photodiode transimpedance amplifier.
Phase
Gain
-20
120
-40
100
-60
80
-80
60
-100
40
-120
20
-140
0
-160
-20
1
10
100
1k
10k
100k
1M
10M
Phase (°)
Gain (dB)
140
1000
0
-180
100M
Voltage Noise (nV/ √ Hz)
160
100
10
1
10
100
1k
10k
100k
1M
Frequency (Hz)
Frequency (Hz)
VS = ±2.5 V, C(L) = 50 pF
VS = 1.8 to 5.5 V
Figure 38. Open-Loop Gain and Phase vs Frequency
Figure 39. Input Voltage Noise Spectral Density vs
Frequency
8.2.2 High-Impedance Sensor Interface
Many sensors have high source impedances that may range up to 10 MΩ, or even higher. The output signal of
sensors often must be amplified or otherwise conditioned by means of an amplifier. The input bias current of this
amplifier can load the sensor output and cause a voltage drop across the source resistance, as shown in
Figure 40, where (V(+INx) = VS – I(BIAS) × R(S)). The last term, I(BIAS) × R(S), shows the voltage drop across R(S). To
prevent errors introduced to the system as a result of this voltage, an op amp with very low input bias current
must be used with high impedance sensors. This low current keeps the error contribution by I(BIAS) × R(S) less
than the input voltage noise of the amplifier, so that it does not become the dominant noise factor. The
OPAx320-Q1 series of op amps feature very low input bias current (typically 200 fA), and are therefore excellent
choices for such applications.
R(S)
100 kΩ
IIB
V(+INx)
V(V+)
OPA320-Q1
V(V–)
VO
R(F)
R(G)
Figure 40. Noise as a Result of I(BIAS)
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
19
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
8.2.3 Driving ADCs
The OPAx320-Q1 series op amps are an excellent choice for driving sampling analog-to-digital converters
(ADCs) with sampling speeds up to 1 MSPS. The zero-crossover distortion input stage topology allows the
OPAx320-Q1 to drive ADCs without degradation of differential linearity and THD.
The OPAx320-Q1 can be used to buffer the ADC switched input capacitance and resulting charge injection while
providing signal gain. Figure 42 shows the OPAx320-Q1 configured to drive the ADS8326.
5V
50 kΩ
(2.5 V)
8
R(G)
REF1004-2.5
R2
25 kΩ
R1
100 kΩ
4
5V
5V
R3
25 kΩ
½
R4
100 kΩ
OPA2320-Q1
½
VO
OPA2320-Q1
G=5+
R(L)
10 kΩ
200 kΩ
R(G)
Figure 41. Two Op-Amp Instrumentation Amplifier With Improved High-Frequency Common-Mode
Rejection
5V
C1
100 nF
5V
(1)
R1
100 Ω
V(V+)
+INx
OPA320-Q1
ADS8326
16-Bit
250kSPS
(1)
C3
1 nF
V(V–)
VI
0 to 4.096 V
–INx
REF IN
Optional
(2)
R2
50 kΩ
5V
SD1
BAS40
–5 V
C2
100 nF
REF3240
4.096V
C4
100 nF
(1) Suggested value; may require adjustment based on specific application.
(2) Single-supply applications lose a small number of ADC codes near ground as a result of op amp output swing limitation. If a negative
power supply is available, this simple circuit creates a –0.3-V supply to allow output swing to true ground potential.
Figure 42. Driving the ADS8326
20
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
8.2.4 Active Filter
The OPAx320-Q1 is an excellent choice for active filter applications that require a wide bandwidth, fast slew rate,
low-noise, single-supply operational amplifier. Figure 43 shows a 500 kHz, second-order, low-pass filter using the
multiple-feedback (MFB) topology. The components have been selected to provide a maximally-flat Butterworth
response. Beyond the cutoff frequency, roll-off is –40 dB/dec. The Butterworth response is excellent for
applications requiring predictable gain characteristics, such as the antialiasing filter used in front of an ADC.
One point to observe when considering the MFB filter is that the output is inverted, relative to the input. If this
inversion is not required, or not desired, a noninverting output can be achieved through one of the following
options:
1. adding an inverting amplifier
2. adding an additional second-order MFB stage
3. using a noninverting filter topology, such as the Sallen-Key
R3
549 Ω
C2
150 pF
R1
549 Ω
R2
1.24 kΩ
V(V+)
VI
VO
OPA320-Q1
C1
1 nF
V(V–)
Figure 43. Second-Order Butterworth 500-kHz Low-Pass Filter
220 pF
1.8 kΩ
19.5 kΩ
150 kΩ
V(V+)
VI = 1 VRMS
3.3 nF
47 pF OPA320-Q1
VO
V(V–)
Figure 44. OPAx320-Q1 Configured as a Three-Pole, 20-kHz, Sallen-Key Filter
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
21
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
9 Power Supply Recommendations
The OPAx320-Q1 are specified for operation from 1.8 V to 5.5 V (±0.9 V to ±2.75 V); many specifications apply
from –40°C to +125°C. Parameters that can exhibit significant variance with regard to operating voltage or
temperature are presented in the Typical Characteristics section.
CAUTION
Supply voltages larger than 6 V can permanently damage the device (see the Absolute
Maximum Ratings table).
Place 0.1-μF bypass capacitors close to the power-supply pins to reduce errors coupling in from noisy or highimpedance power supplies. For more detailed information on bypass capacitor placement, see the Layout
Guidelines section.
10 Layout
10.1 Layout Guidelines
For best operational performance of the device, use good PCB layout practices, including:
• Noise can propagate into analog circuitry through the power pins of the circuit as a whole and operational
amplifier itself. Bypass capacitors are used to reduce the coupled noise by providing low-impedance
power sources local to the analog circuitry.
– Connect low-ESR, 0.1-µF ceramic bypass capacitors between each supply pin and ground, placed as
close to the device as possible. A single bypass capacitor from V+ to ground is applicable for singlesupply applications.
• Separate grounding for analog and digital portions of circuitry is one of the simplest and most-effective
methods of noise suppression. One or more layers on multilayer PCBs are usually devoted to ground
planes. A ground plane helps distribute heat and reduces EMI noise pickup. Make sure to physically
separate digital and analog grounds, paying attention to the flow of the ground current. For more detailed
information, refer to the Circuit Board Layout Techniques Application Report.
• To reduce parasitic coupling, run the input traces as far away from the supply or output traces as
possible. If it is not possible to keep them separate, it is much better to cross the sensitive trace
perpendicular as opposed to in parallel with the noisy trace.
• Place the external components as close to the device as possible. As shown in Figure 45, keeping RF
and RG close to the inverting input will minimize parasitic capacitance.
• Keep the length of input traces as short as possible. Always remember that the input traces are the most
sensitive part of the circuit.
• Consider a driven, low-impedance guard ring around the critical traces. A guard ring can significantly
reduce leakage currents from nearby traces that are at different potentials.
22
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
10.2 Layout Example
Run the input traces
as far away from
the supply lines
VIN
as possible.
VS±
VS+
+IN
V+
Use a low-ESR,
ceramic bypass
capacitor.
V±
Use a low-ESR,
ceramic bypass
capacitor.
GND
RG
OUT
±IN
VOUT
GND
Place components
close to the device
and to each other to
reduce parasitic
errors.
RF
Copyright © 2016, Texas Instruments Incorporated
Figure 45. Operational Amplifier Board Layout for Noninverting Configuration
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
23
OPA320-Q1, OPA2320-Q1
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
www.ti.com
11 Device and Documentation Support
11.1 Device Support
11.1.1 Development Support
For related documentation see the following:
• Texas Instruments, ADS8326 16-Bit, High-Speed, 2.7V to 5.5V microPower Sampling Analog-to-Digital
Converter Data Sheet
• Texas Instruments, Compensate Transimpedance Amplifiers Intuitively Application Report
• Texas Instruments, Noise Analysis of FET Transimpedance Amplifiers Application Bulletin
• Texas Instruments, Noise Analysis for High-Speed Op Amps Application Report
• Texas Instruments, OPAx380 Precision, High-Speed Transimpedance Amplifier Data Sheet
• Texas Instruments, OPAx354 250MHz, Rail-to-Rail I/O, CMOS Operational Amplifiers Data Sheet
• Texas Instruments, OPAx355 200MHz, CMOS Operational Amplifier With Shutdown Data Sheet
• Texas Instruments, OPA656 Wideband, Unity-Gain Stable, FET-Input Operational Amplifier Data Sheet
11.2 Related Links
Table 1 lists quick access links. Categories include technical documents, support and community resources,
tools and software, and quick access to sample or buy.
Table 1. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
OPA320-Q1
Click here
Click here
Click here
Click here
Click here
OPA2320-Q1
Click here
Click here
Click here
Click here
Click here
11.3 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
11.4 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.5 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.6 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
24
Submit Documentation Feedback
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
OPA320-Q1, OPA2320-Q1
www.ti.com
SLOS884B – SEPTEMBER 2014 – REVISED DECEMBER 2018
11.7 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Copyright © 2014–2018, Texas Instruments Incorporated
Product Folder Links: OPA320-Q1 OPA2320-Q1
Submit Documentation Feedback
25
PACKAGE OPTION ADDENDUM
www.ti.com
6-Feb-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
OPA2320AQDGKRQ1
ACTIVE
VSSOP
DGK
8
2500
Green (RoHS
& no Sb/Br)
NIPDAUAG
Level-2-260C-1 YEAR
-40 to 125
ZAEV
OPA320AQDBVRQ1
ACTIVE
SOT-23
DBV
5
3000
Green (RoHS
& no Sb/Br)
NIPDAU
Level-2-260C-1 YEAR
-40 to 125
15DD
OPA320AQDBVTQ1
ACTIVE
SOT-23
DBV
5
250
Green (RoHS
& no Sb/Br)
NIPDAU
Level-2-260C-1 YEAR
-40 to 125
15DD
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of