INA190EVM Circuit and Components
5
SBOU201A – April 2018 – Revised September 2018
Copyright © 2018, Texas Instruments Incorporated
INA190EVM User's Guide
4
INA190EVM Circuit and Components
This section summarizes the INA190EVM components. For the following instructions, x = 1 to 5 or a
[blank].
4.1
R5x, R6x, R7x, R3x,C2x, C3x, C4x, C9x
R5x, R6x, R7x, and R3x are factory-installed 0-
Ω
resistors. C2x, C3x, C4x, and C9x are not populated
except for C9x. Collectively, these pads allow for user-defined filters for the input, reference signal, and
output. If a filter is desired, remove these resistors and replace them with > 0-
Ω
SMT resistors and
populate the capacitor pads with capacitors. Additional information regarding the use of input filtering is
provided in
INA190 Low Supply, Voltage Output, Low- or High-Side Measurement, Bidirectional, Zero-Drift
Series, Current-Shunt Monitors
.
4.2
C1x, C5x
C1x and C5x are 0.1-µF power supply bypass capacitors.
4.3
R1x, R2x
R1x and R2x are resistors used to divide down VS supply voltage and drive a custom, on-board reference
voltage into U2x if R2x and U2x are populated.
4.4
R4
R4 is a connection resistor for the "Guarded Inputs" panel. Populate this with a 0-
Ω
resistor to connect the
guarding plane to automatically be driven to the same voltage as the input common-mode voltage. This
may only be necessary if measuring very small currents at high common-mode voltages.
4.5
R8x
R8x is unpopulated, but allows a surface-mount shunt resistor to be soldered down in between the IN+
and IN– inputs. If used, ensure R8x has proper power dissipation for the user-set current load. This
resistor chosen must at a minimum have a 0603 Imperial footprint.
4.6
U1x - INA190
U1x is the location for the INA190x test device. Six device boards are supplied with the INA190EVM
board. Each board is populated with one of the available device gains. This option allows users to test the
devices and determine the gain setting that is best suited for a given application.
The following list of factors are involved in selecting the appropriate device:
•
The INA190 devices are identical with the exception of different gain settings.
•
The differential input voltage is either applied across the inputs or developed based on the load current
that flows through the shunt resistor.
•
The limiting factor that requires attention to be given to device selection is the output voltage not
exceeding the supply voltage or going below GND.
•
The selected device must allow the output voltage to remain within the acceptable range after the
developed input voltage is amplified by the respective device gain. The output voltage must remain
with the swing limitations specified for the device for response in the linear range.
•
An output below the minimum allowable output requires the selection of a device with a higher gain.
Likewise, an output above the maximum allowable output requires the selection of a device with a
lower gain.
4.7
U2x
U2x is not populated, but allows a SOT-23-5 operational amplifier to be soldered to the EVM. In
conjunction with populating R1x and R2x with the desired ratio of resistances, U2x provides a low-
impedance voltage source for the REF pin of the INA190. Two options to populate this pad are
TLV6001IDBVR and TLV379IDBV.
