Hardware
4
SBOU167 – March 2019
Copyright © 2019, Texas Instruments Incorporated
INA185EVM
2
Hardware
The INA185 is an integrated, op amp-based current sense circuit that provides ease of use and high
performance. The INA185EVM is intended to provide basic functional evaluation of this device family. The
board layout is neither intended to be a model for the target circuit, nor is it laid out for electromagnetic
compatibility (EMC) testing. The INA185EVM consists of one PCB that can be cut into four individual
PCBs segments, one for each of the four device gain options.
2.1
Features
The layout of the INA185EVM printed-circuit board (PCB) is designed to provide the following features:
•
Evaluation of all gain options for the INA185
•
Ease of access to device pins with test points
•
Capability to evaluate high-side and low-side configurations
•
Capability to provide a buffered reference through a user defined voltage divider
See the INA185 data sheet (
) for comprehensive information about the INA185 family of
devices.
3
Quick Start Setup and Use
The following instructions show how to set up and use the INA185 devices with the INA185EVM. For the
circuits in the following instructions, x = A to D.
Step 1.
Connect an external dc supply voltage between 2.7-V and 5.5-V to the VCC test point TP2x,
and connect the ground reference of that supply to one of the GND test points: TP7x, TP8x,
or TP9x.
Step 2.
The REF pin is connected to the GND pin in the default board. The voltage applied at the
reference input varies depending on how the device is going to be used. Further details
regarding the use of the reference voltage are discussed later in this document.
Step 3.
Connect the input as described in
.
3.1
Measurements
The INA185EVM can either simulate the voltage developed across a sense resistor based on a given set
of system conditions, or connect remotely to an existing shunt already included in a user application.
The following procedures are used to configure a measurement evaluation without a shunt. For the circuits
in the following instructions, x = A to D.
Step 1.
Connect a differential voltage to the IN+ (TP6x) and IN– (TP3x) test points. With the
reference voltage set at ground, make sure that the IN+ pin is the more positive of the two
inputs.
Step 2.
Measure the output voltage at the OUT test point (TP4x or TP5x).
NOTE:
The output voltage is equal to the gain of the device multiplied by the differential voltage
measured directly at the device input pins.