TI1 INA190 Low supply, voltage output, low- or high-side measurement, bidirectional, zero-drift series, current-shunt monitor Datasheet

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INA190
SBOS863 – MARCH 2018
INA190 Low Supply, Voltage Output, Low- or High-Side Measurement, Bidirectional,
Zero-Drift Series, Current-Shunt Monitors
1 Features
3 Description
•
•
•
•
•
The INA190 series of devices are voltage-output,
current-shunt monitors (also called current-sense
amplifiers) that are commonly used for overcurrent
protection, precision-current measurement for system
optimization, or in closed-loop feedback circuits. This
series of devices can sense drops across shunts at
common-mode voltages from –0.1 V to +40 V,
independent of the supply voltage. Five fixed gains
are available: 25 V/V, 50 V/V, 100 V/V, 200 V/V, or
500 V/V. The low input bias current of the INA190
permits the use of larger current-sense resistors, thus
providing accurate current measurements in the µA
range. The low offset voltage of the zero-drift
architecture extends the dynamic range of the current
measurement. Therefore, much smaller shunt-voltage
drops are allowed during high-current measurements,
thus minimizing resistor power loss while still
maintaining accurate current measurements.
1
•
•
•
•
Low Supply Voltage, VVS: 1.7 V to 5.5 V
Wide Common-Mode Voltage: –0.1 V to +40 V
Low Shutdown Current: 500 nA (Max)
Low Input Bias Currents: 500 pA (Typ)
Low Offset Voltage, VOS: ±15 μV (Max, INA190A2)
(Enables Shunt Drops of 10-mV Full-Scale)
Accuracy:
– ±0.3% Gain Error (Max Over Temperature)
– 0.13-μV/°C Offset Drift (Max)
– 5-ppm/°C Gain Drift (Max)
Gain Options:
– INA190A1: 25 V/V
– INA190A2: 50 V/V
– INA190A3: 100 V/V
– INA190A4: 200 V/V
– INA190A5: 500 V/V
Quiescent Current: 40 μA at 25°C (Typ)
Packages: SC70, UQFN, and DSBGA
2 Applications
•
•
•
•
•
•
These devices operate from a single 1.7-V to 5.5-V
power supply, drawing a maximum of 70 µA of supply
current when enabled and only 0.5 µA when disabled.
All versions are specified over the extended operating
temperature range of –40°C to +125°C, and offered
in SC70, UQFN, and DSBGA packages.
Device Information(1)
Notebook Computers
Cell Phones
Battery-Powered Devices
Telecom Equipment
Power Management
Battery Chargers
PART NUMBER
INA190(2)
PACKAGE
BODY SIZE (NOM)
UQFN (10)
1.80 mm × 1.40 mm
DSBGA (6)
1.20 mm × 0.80 mm
SC70 (6)
2.00 mm × 1.25 mm
(1) For all available packages, see the package option addendum
at the end of the datasheet.
(2) DSBGA and SC70 packages are preview.
Simplified Schematic
Bus Voltage
±0.1 V to +40 V
0.5 nA
(typ)
Supply Voltage
1.7 V to 5.5 V
RSENSE
LOAD
0.1 …F
0.5 nA
(typ)
ENABLE
VS
IN±
INA190
OUT
ADC
Microcontroller
IN+
NOTE: ENABLE pin only available in
UQFN-10 and DSBGA-6 packages.
GND
REF
Copyright © 2018, Texas Instruments Incorporated
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. UNLESS OTHERWISE NOTED, this document contains ADVANCE
INFORMATION for pre-production products; subject to change without notice.
INA190
SBOS863 – MARCH 2018
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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
4
4
4
4
5
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
8
8.1 Application Information............................................ 10
8.2 Typical Applications ................................................ 13
9 Power Supply Recommendations...................... 14
10 Layout................................................................... 14
10.1 Layout Guidelines ................................................. 14
10.2 Layout Example .................................................... 14
11 Device and Documentation Support ................. 16
11.1
11.2
11.3
11.4
11.5
11.6
Detailed Description .............................................. 6
7.1
7.2
7.3
7.4
Overview ...................................................................
Functional Block Diagram .........................................
Feature Description...................................................
Device Functional Modes..........................................
Application and Implementation ........................ 10
6
6
7
9
Documentation Support ........................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
16
16
16
16
16
16
12 Mechanical, Packaging, and Orderable
Information ........................................................... 16
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
2
DATE
REVISION
NOTES
March 2018
*
Initial release.
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5 Pin Configuration and Functions
YFD Package(1)
6-Pin DSBGA
Top View
NC
OUT
GND
REF
10
9
8
RSW Package
10-Pin Thin UQFN
Top View
1
NC
7
2
6
1
2
3
A
IN+
VS
OUT
B
IN±
GND
ENABLE
ENABLE
VS
5
4
NC
IN+
IN±
3
Not to scale
Not to scale
DCK Package(1)
6-Pin SC70
Top View
REF
1
6
OUT
GND
2
5
IN±
VS
3
4
IN+
Not to scale
(1)
DCK (SC70) and YFD (DSBGA) packages are preview.
Pin Functions
PIN
NAME
NO.
I/O
DESCRIPTION
DCK
RSW
YFD
GND
2
9
B2
Analog
Ground
IN–
5
4
B1
Analog
input
Current-sense amplifier negative input. For high-side applications, connect to load
side of sense resistor. For low-side applications, connect to ground side of sense
resistor.
IN+
4
3
A1
Analog
input
Current-sense amplifier positive input. For high-side applications, connect to bus
voltage side of sense resistor. For low-side applications, connect to load side of
sense resistor.
NC
—
1, 2, 5
—
—
OUT
6
10
A3
Analog
output
The OUT pin provides an analog voltage output that is the gained up voltage
difference from the IN+ to the IN– pins.
REF
1
8
—
Analog
input
Reference input. Enables bidirectional current sensing with an externally applied
voltage.
ENABLE
—
7
B3
Digital
input
Enable Pin. Active high logic pin enables/disables amplifier bias current. Must be
driven externally or connected to VVS if not used.
VS
3
6
A2
Analog
Power supply, 1.7 V to 5.5 V
Not internally connected. Either float these pins or connect to any voltage between
GND and VS.
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
Supply voltage, VVS
Analog inputs, VIN+, VIN–
Differential (VIN+) – (VIN–)
(2)
Common-mode, VCM
(3)
ENABLE
REF, OUTPUT
(3)
V
–42
42
42
GND – 0.3
6
GND – 0.3
(VVS) + 0.3
V
5
mA
150
°C
150
°C
150
°C
Operating temperature, TA
–55
Junction temperature, TJ
Storage temperature, Tstg
(2)
(3)
UNIT
6
GND – 0.3
Input current into any pin (3)
(1)
MAX
–65
V
V
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
VIN+ and VIN– are the voltages at the IN+ and IN– pins, respectively.
Input voltage at any pin may exceed the voltage shown if the current at that pin is limited to 5 mA.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±TBD
Charged-device model (CDM), per JEDEC specification JESD22-C101 (2)
±TBD
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
VCM
Common-mode input range
VVS
TA
NOM
MAX
UNIT
–0.1
40
V
Operating supply voltage
1.7
5.5
V
Operating free-air temperature
–40
125
°C
6.4 Thermal Information
INA190
THERMAL METRIC (1)
RSW (UQFN)
UNIT
10 PINS
RθJA
Junction-to-ambient thermal resistance
163.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
78.7
°C/W
RθJB
Junction-to-board thermal resistance
93.3
°C/W
ψJT
Junction-to-top characterization parameter
4.1
°C/W
ψJB
Junction-to-board characterization parameter
92.8
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
N/A
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
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6.5 Electrical Characteristics
at TA = 25°C, VSENSE = VIN+ – VIN–, VVS = 1.8 V, VIN+ = 12 V, VREF = VVS / 2 (RSW package only), and VENABLE = VVS (unless
otherwise noted)
PARAMETER
CONDITIONS
MIN
TYP
120
140
MAX
UNIT
INPUT
CMRR
Common-mode rejection ratio
VO
Offset voltage, RTI (1)
VSENSE = 0 mV, VIN+ = 0 V to 40 V,
TA = –40°C to +125°C
A3, A4, A5 devices, VSENSE = 0 mV
dB
±0.5
±20
A1 device, VSENSE = 0 mV
±2
±25
A2 device, VSENSE = 0 mV
±1
±15
µV
dVOS/dT
Offset drift, RTI
VSENSE = 0 mV, TA = –40°C to +125°C
0.05
0.13
µV/°C
PSRR
Power-supply rejection ratio, RTI
VSENSE = 0 mV, VVS = 1.7 V to 5.5 V
±0.1
±10
µV/V
IIB
Input bias current
VSENSE = 0 mV
0.5
10
nA
IIO
Input offset current
VSENSE = 0 mV
±0.07
15
nA
OUTPUT
A1 devices
G
Gain
EG
RVRR
25
A2 devices
50
A3 devices
100
A4 devices
200
A5 devices
500
V/V
A5 device
±0.01%
±0.4%
Other devices
±0.01%
±0.3%
2
5
Gain error
VOUT = 0.1 V to VS – 0.1 V,
TA = –40°C to +125°C
Gain error vs temperature
TA = –40°C to +125°C
Nonlinearity error
VOUT = 0.1 V to VVS – 0.1 V
Reference voltage rejection ratio
TA = –40°C to +125°C,
VREF = 100 mV to VVS – 100 mV
4
µV/V
Maximum capacitive load
No sustained oscillation
1
nF
ppm/°C
±0.01%
VOLTAGE OUTPUT
VSP
VSN
Swing to VVS power-supply rail
RL = 10 kΩ to GND, TA = –40°C to +125°C
(VVS) – 25
(VVS) – 45
mV
Swing to GND
RL = 10 kΩ to GND, TA = –40°C to +125°C,
VSENSE = -10 mV, VREF = 0 V
(VGND) + 1
(VGND) + 5
mV
Zero current output voltage
RL = 10 kΩ to GND, TA = –40°C to +125°C,
VSENSE = 0 mV, VREF = 0 V
(VGND) + 6
(VGND) + 10
mV
FREQUENCY RESPONSE
BW
Bandwidth
A1 devices, CLOAD = 10 pF
40
A2 devices, CLOAD = 10 pF
37
A3 devices, CLOAD = 10 pF
35
A4 devices, CLOAD = 10 pF
30
A5 devices, CLOAD = 10 pF
SR
Slew rate
VVS = 5.0 V, VOUT = 0.5 V to 4.5 V
tS
Settling time
From current step to within 1% of final value
kHz
20
0.25
V/µs
30
µs
70
nV/√Hz
NOISE, RTI (1)
Voltage noise density
ENABLE
0 V ≤ VENABLE ≤ VVS
IEN
Leakage input current
1
µA
VIH
High-level input voltage
0.7 × VVS
6
V
VIL
Low-level input voltage
0
0.3 × VVS
VHYS
Hysteresis
IODIS
Disabled output leakage
VVS = 5 V, VOUT = 0 V to 5 V, VENABLE = 0 V
0.1
V
300
mV
1
µA
POWER SUPPLY
IQ
Quiescent current
IQDIS
Quiescent current disabled
(1)
VSENSE = 0 mV
40
VSENSE = 0 mV, TA = –40°C to +125°C
VENABLE < 0.4, VSENSE = 0 mV
10
70
µA
100
µA
500
nA
RTI = referred-to-input.
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7 Detailed Description
7.1 Overview
The INA190 is a low bias current, 40-V common-mode, current-sensing amplifier with an enable pin. When
disabled, the output goes to a high impedance state and the supply current draw is reduced to less than 0.5 µA.
The INA190 is intended for use in either low-side and high-side current-sensing configurations where high
accuracy and low current consumption are required. The INA190 is a specially-designed, current-sensing
amplifier that accurately measure voltages developed across current-sensing resistors on common-mode
voltages that far exceed the supply voltage. Current can be measured on input voltage rails as high as 40 V, with
a supply voltage as low as 1.7 V.
7.2 Functional Block Diagram
VS
ENABLE
INA190
IN±
±
±
±
OUT
+
+
+
IN+
REF
GND
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7.3 Feature Description
7.3.1 Precision Current Measurement
The INA190 allows for extremely accuracy current measurements over a wide dynamic range. The high accuracy
of the device is attributable to the gain error and offset specifications. The offset voltage of the INA190A2 is less
than 15 µV. The low offset allows the device to be used in applications that measure current over a wide
dynamic range. In this case, the low offset improves the accuracy when the sensed currents are on the low end
of the measurement range. Another advantage of low offset is the ability to use a lower-value shunt resistor,
which reduces the power loss in the current-sense circuit, and improves the power efficiency of the end
application.
The gain error of the INA190 is specified to be within 0.3% of the actual value. As the sensed voltage becomes
much larger than the offset voltage, the sensed voltage becomes the dominant source of error in the currentsense measurement. When the device is monitoring currents near the full-scale output range, the total
measurement error approaches the value of the gain error.
Featuring both low offset and small gain error, the INA190 is capable of accurately measuring currents over a
wider range of currents while using the same current-sense resistor.
7.3.2 Low Input Bias Current
The INA190 is different from most current-sense amplifiers in that this device offers very low input bias current.
The low input bias current of the INA190 (0.5 nA, typically) has three primary benefits.
The first benefit is the reduction of the current consumed by the device in both the enabled and disabled states.
Classical current-sense amplifier topologies typically consume tens of microamps of current in the resistor divider
network that determines the gain. To reduce the bias current to near zero, the INA190 uses a capacitively
coupled amplifier on the input stage, followed by a difference amplifier on the output stage.
The second benefit of low bias current is the ability to use a larger current-sense resistor, which allows the
device to accurately monitor currents as low as 1 µA.
The third benefit of low bias current is the ability to use input filters to reject high-frequency noise before the
signal is amplified. In a traditional current-sense amplifier, the addition of input filters comes with the price of
reduced accuracy; however, as a result of the low bias currents, input filters have little effect on the
measurement accuracy of the INA190.
7.3.3 Low Quiescent Current with Output Enable
The device features low quiescent current (IQ), while still providing sufficient small-signal bandwidth to be usable
in most applications. The quiescent current of the INA190 is only 40 µA (typ), while providing a small-signal
bandwidth of 35 kHz in a gain of 100. The low IQ and good bandwidth allows the device to be used in many
portable electronic systems without concern of excessive drain on the battery. Because many applications only
need to periodically monitor current, the INA190 features an enable pin that turns off the device until needed.
When in the disabled state the INA190 typically draws 10 nA of total supply current.
7.3.4 Bidirectional Current Monitoring
INA190 devices that have a REF pin sense current flow through a sense resistor in both directions. The
bidirectional, current-sensing capability is achieved by applying a voltage at the REF pin to offset the output
voltage. A positive, differential voltage sensed at the inputs results in an output voltage that is greater than the
applied reference voltage; likewise, a negative differential voltage at the inputs results in output voltage that is
less than the applied reference voltage. The output voltage of the current-sense amplifier is shown in Equation 1.
VOUT
I LOAD u RSENSE u GAIN
VREF
where
•
•
•
•
ILOAD is the load current to be monitored.
RSENSE is the current-sense resistor.
GAIN is the gain option of the selected device.
VREF is the voltage applied to the REF pin.
(1)
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Feature Description (continued)
7.3.5 High-Side and Low-Side Current Sensing
The INA190 supports input common-mode voltages from –0.1 V to +40 V. Because of the internal topology, the
common-mode range is not restricted by the power-supply voltage (VVS) as long as VVS stays within the
operational range of 1.7 V to 5.5 V. The ability to operate with common-mode voltages greater or less than VVS
allows the INA190 to be used in high-side, as well as low-side, current-sensing applications, as shown in
Figure 1.
Bus Supply
±0.1 V to +40 V
Direction of Positive
Current Flow
IN+
RSENSE
High-Side Sensing
Common-mode voltage (VCM)
is bus-voltage dependent.
IN±
LOAD
Direction of Positive
Current Flow
IN+
RSENSE
Low-Side Sensing
Common-mode voltage (VCM)
is always near ground and is
isolated from bus-voltage spikes.
IN±
Figure 1. High-Side and Low-Side Sensing Connections
7.3.6 High Common-Mode Rejection
The INA190 uses a capacitively coupled amplifier on the front end; therefore, dc common-mode voltages are
blocked from downstream circuits, resulting in very high common-mode rejection. Typically, the common-mode
rejection of the INA190 is approximately 140 dB. The ability to reject changes in the dc common-mode voltage
allows the INA190 to monitor both high and low voltage rail currents with very little change in the offset voltage.
7.3.7 Rail-to-Rail Output Swing
The INA190 allows linear current-sensing operation with the output close to the supply rail and ground. The
maximum specified output swing to the positive rail is 45 mV, and the maximum specified output swing to GND is
only 5 mV. The close to rail output swing is useful to maximize the usable output range particularly when
operating the device from a 1.8-V supply.
8
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7.4 Device Functional Modes
7.4.1 Normal Operation
The INA190 is in normal operation when the following conditions are met:
• The power-supply voltage (VVS) is between 1.7 V and 5.5 V.
• The common-mode voltage (VCM) is within the specified range of –0.1 V to +40 V.
• The maximum differential input signal times the gain plus VREF is less than VVS minus the output voltage
swing to VVS.
• The minimum differential input signal times the gain plus VREF is greater than the swing to GND (see the Railto-Rail Output Swing section).
During normal operation, this device produces an output voltage that is the gained-up representation of the
difference voltage from IN+ to IN– plus the reference voltage at VREF.
7.4.2 Shutdown
The INA190 features an active high ENABLE pin that when pulled to a logic low signal shuts down the device.
When shut down, the quiescent current is reduced to 10 nA (typ), and the output goes to a high-impedance state.
The low quiescent current extends the battery lifetime when the current measurement is not needed. When the
ENABLE pin is driven to a logic-high level, the device turns back on. The typical output setting time when
enabled is 130 µs.
The output of the INA190 goes to a high-impedance state when disabled; therefore, it is possible to connect
multiple outputs of the INA190 together to a single ADC or measurement device, as shown in Figure 2.
Bus Voltage1
±0.1 V to +40 V
RSENSE
Supply Voltage
1.7 V to 5.5 V
LOAD
0.1 F
ENABLE
GPIO1
VS
IN±
INA190
ADC
OUT
Microcontroller
IN+
GPIO2
REF
GND
Bus Voltage2
±0.1 V to +40 V
RSENSE
Supply Voltage
1.7 V to 5.5 V
LOAD
0.1 F
ENABLE
VS
IN±
INA190
OUT
IN+
GND
REF
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Figure 2. Multiplexing Multiple Devices With the ENABLE Pin
When connected in this way, enable only one INA190 at a time and both devices must have the same supply
voltage.
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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 INA190 amplifies the voltage developed across a current-sensing resistor as current flows through the
resistor to the load or ground. The ability to drive the reference pin to adjust the functionality of the output signal
offers multiple configurations, as discussed in previous sections.
8.1.1 Basic Connections
Figure 3 shows the basic connections of the INA190. Connect the input pins (IN+ and IN–) as closely as possible
to the shunt resistor to minimize any resistance in series with the shunt resistor. The ENABLE pin must be
controlled externally or connected to VS if not used.
Supply Voltage
1.7 V to 5.5 V
RSENSE
Bus Voltage
±0.1 V to +40 V
LOAD
0.5 nA
(typ)
0.1 …F
0.5 nA
(typ)
ENABLE
VS
IN±
INA190
OUT
ADC
Microcontroller
IN+
NOTE: ENABLE pin only available in
UQFN-10 and DSBGA-6 packages.
GND
REF
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NOTE: To help eliminate ground offset errors between the device and the analog-to-digital converter (ADC), connect
the REF pin to the ADC reference input.
Figure 3. Basic Connections for the INA190
10
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Application Information (continued)
8.1.2 RSENSE and Device Gain Selection
The accuracy of any current-sense amplifier is maximized by choosing the current-sense resistor to be as large
as possible. A large sense resistor maximizes the differential input signal for a given amount of current flow and
reduces the error contribution of the offset voltage. However, there are practical limits as to how large the
current-sense resistor can be in a given application because of the resistor size and maximum allowable power
dissipation. Equation 2 gives the maximum value for the current-sense resistor for a given power dissipation
budget:
PDMAX
RSENSE
IMAX2
where:
•
•
PDMAX is the maximum allowable power dissipation in RSENSE.
IMAX is the maximum current that will flow through RSENSE.
(2)
An additional limitation on the size of the current-sense resistor and device gain is due to the power-supply
voltage, VVS, and device swing-to-rail limitations. In order to make sure that the current-sense signal is properly
passed to the output, both positive and negative output swing limitations must be examined. Equation 3 provides
the maximum values of RSENSE and GAIN to keep the device from hitting the positive swing limitation.
IMAX u RSENSE u GAIN < VSP VREF
where:
•
•
•
•
IMAX is the maximum current that will flow through RSENSE.
GAIN is the gain of the current-sense amplifier.
VSP is the positive output swing as specified in the data sheet.
VREF is the externally applied voltage on the REF pin.
(3)
To avoid positive output swing limitations when selecting the value of RSENSE, there is always a trade-off between
the value of the sense resistor and the gain of the device under consideration. If the sense resistor selected for
the maximum power dissipation is too large, then it is possible to select a lower-gain device in order to avoid
positive swing limitations.
The negative swing limitation places a limit on how small of a sense resistor can be used in a given application.
Equation 4 provides the limit on the minimum size of the sense resistor.
IMIN u RSENSE u GAIN > VSN VREF
where:
•
•
•
•
IMIN is the minimum current that will flow through RSENSE.
GAIN is the gain of the current-sense amplifier.
VSN is the negative output swing of the device (see Rail-to-Rail Output Swing).
VREF is the externally applied voltage on the REF pin.
(4)
In addition to adjusting RSENSE and the device gain, the voltage applied to the REF pin can be slightly increased
above GND to avoid negative swing limitations.
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Application Information (continued)
8.1.3 Output Signal Conditioning
When performing accurate current measurements in noisy environments, it is common to filter the currentsensing signal. The INA190 features low input bias currents; therefore, it is possible to add a differential mode
filter to the input without sacrificing the current-sense accuracy. Filtering at the input is advantageous because
this action attenuates differential noise before the signal is amplified. Figure 4 provides an example of how a filter
can be used on the input pins of the device.
Bus Voltage
±0.1 V to +40 V
VVS
1.7 V to 5.5 V
RSENSE
Load
ENABLE
RF < 100
f3dB
1
4SRFCF
CF
RF < 100
VS
RINT
IN±
Capacitively
Coupled
Amplifier
±
OUT
VOUT
REF
VREF
+
RINT
IN+
Copyright © 2018, Texas Instruments Incorporated
Figure 4. Filter at Input Pins
When using the INA190 in applications where there are periodic high-frequency currents that are above the
bandwidth of the device (for example, sensing the input current of a dc-dc convertor), it is highly recommended
to apply an input filter to attenuate differential current noise. Using a 100-Ω resistor for RF and a 22-nF capacitor
for CF results in a low-pass filter corner frequency of 36.2 kHz, which does not severely impact the currentsensing bandwidth, but does filter out most high-frequency signals. If a lower corner frequency is desired,
increase the value of CF.
If high-frequency, common-mode noise is a concern, add an RC filter from the OUT pin to ground. The value for
the resistance of the RC filter is limited by the impedance of the load. Any current drawn by the load manifests as
an external voltage drop from the INA190 OUT pin to the load input.
12
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8.2 Typical Applications
8.2.1 Microamp Current Measurement
The low input bias current of the INA190 allows accurate monitoring of small-value currents. To accurately
monitor currents on the microamp range, increase the value of the sense resistor to increase the sense voltage,
so that the error introduced by the offset voltage is small. The circuit configuration for monitoring low-value
currents is shown in Figure 5. As a result of the differential input impedance of the INA190, limit the value of
RSENSE to 1 kΩ or less for best accuracy.
RSENSE ” 1kO
12 V
LOAD
5V
0.1 F
ENABLE
VS
IN±
INA190
OUT
IN+
GND
REF
Copyright © 2018, Texas Instruments Incorporated
Figure 5. Measuring Microamp Currents
8.2.1.1 Design Requirements
The design requirements for the circuit shown in Figure 5, are listed in Table 1
Table 1. Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
Power-supply voltage (VVS)
5V
Bus supply rail (VCM)
12 V
Minimum sense current (IMIN)
1 µA
Maximum sense current (IMAX)
150 µA
Device gain (GAIN)
25 V/V
VREF
0V
8.2.1.2 Detailed Design Procedure
The maximum value of the current-sense resistor is calculated based choice of gain, value of the maximum
current the be sensed (IMAX), and the power supply voltage(VVS). When operating at the maximum current, the
output voltage must not exceed the positive output swing specification, VSP. Using Equation 5, for the given
design parameters the maximum value for RSENSE is calculated to be 1.321 kΩ.
VSP
RSENSE <
IMAX u GAIN
(5)
However, because this value exceeds the maximum recommended value for RSENSE, a resistance value of 1 kΩ
must be used. When operating at the minimum current value, IMIN the output voltage must be greater than the
swing to GND (VSN), specification. For this example, the output voltage at the minimum current is calculated
using Equation 6 to be 25 mV, which is greater than the value for VSN.
VOUTMIN IMIN u RSENSE u GAIN
(6)
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9 Power Supply Recommendations
The input circuitry of the INA190 accurately measures beyond the power-supply voltage, VVS. For example, VVS
can be 5 V, whereas the bus supply voltage at IN+ and IN– can be as high as 40 V. However, the output voltage
range of the OUT pin is limited by the voltage on the VS pin. The INA190 also withstands the full differential input
signal range up to 40 V at the IN+ and IN– input pins, regardless of whether or not the device has power applied
at the VS pin.
10 Layout
10.1 Layout Guidelines
•
•
•
Connect the input pins to the sensing resistor using a Kelvin or 4-wire connection. This connection technique
makes sure that only the current-sensing resistor impedance is detected between the input pins. Poor routing
of the current-sensing resistor commonly results in additional resistance present between the input pins.
Given the very low ohmic value of the current resistor, any additional high-current carrying impedance can
cause significant measurement errors.
Place the power-supply bypass capacitor as close as possible to the device power supply and ground pins.
The recommended value of this bypass capacitor is 0.1 µF. Additional decoupling capacitance can be added
to compensate for noisy or high-impedance power supplies.
When routing the connections from the current-sense resistor to the device, keep the trace lengths as short
as possible. The input filter capacitor CF should be placed as close as possible to the input pins of the device.
10.2 Layout Example
RSHUNT
RF
RF
CF
NC
IN-
IN+
5
4
3
CBYPASS
Connect to Supply
(1.7 V to 5.5 V)
VS
6
2
NC
Connect to Control or VS
(Do Not Float)
ENABLE
7
1
NC
8
9
10
REF GND OUT
VIA to Ground
Plane
Current
Sense Output
Connect REF to GND for
Unidirectional Measurement
or to External Reference for
Bidirectional Measurement
Figure 6. Recommended Layout for UQFN (RSW) Package
14
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Layout Example (continued)
RSHUNT
RF
RF
CF
VIA to Ground
Plane
IN±
A1
A2
IN+
GND
B1
B2
VS
ENABLE
C1
C2
OUT
Connect to Supply
(1.7 V to 5.5 V)
CBYPASS
Current
Sense Output
Connect to Control or VS
(Do not float)
Figure 7. Recommended Layout DSBGA (YFD) Package
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11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
For related documentation see the following:
INA190EVM User's Guide
11.2 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.
11.3 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.
11.4 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.5 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.
11.6 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.
16
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PACKAGE OPTION ADDENDUM
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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)
PINA190A1IRSWT
ACTIVE
UQFN
RSW
10
250
TBD
Call TI
Call TI
-40 to 125
PINA190A2IRSWT
ACTIVE
UQFN
RSW
10
250
TBD
Call TI
Call TI
-40 to 125
PINA190A3IRSWT
ACTIVE
UQFN
RSW
10
250
TBD
Call TI
Call TI
-40 to 125
PINA190A4IRSWT
ACTIVE
UQFN
RSW
10
250
TBD
Call TI
Call TI
-40 to 125
PINA190A5IRSWT
ACTIVE
UQFN
RSW
10
250
TBD
Call TI
Call TI
-40 to 125
(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 <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
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11-Apr-2018
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 2
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