INA301EVM Hardware
2.3
Quick-Start Setup and Use
Follow these procedures to set up and use the INA301EVM:
1. Connect an external dc supply voltage between 2.7 V and 5.5 V to the J3-1 terminal.
2. Connect the desired input to the J4 terminal. This input is either a remote shunt resistor or a differential
voltage source with a common-mode voltage of 0 V to 36 V referenced to GND.
2.4
Voltage Inputs
The J4 terminal (VIN+ and VIN–) is used to connect to a remote shunt resistor or a differential voltage
source. The voltage differential is multiplied by the 20-V/V device gain of the INA301A1. Other devices in
this family are the INA301A2 with 50-V/V gain and the INA301A3 with 100-V/V gain. The full-scale sense
input voltage (V
SENSE
) is defined as VIN+ – VIN–, and has a maximum input of (V+ – 0.20) / gain in order
to achieve linear output. The minimum voltage output is 10 mV.
2.5
Comparator Trip Point
The integrated comparator in the INA301 has a resistor programmable threshold. Connecting an
appropriately sized resistor on the LIMIT pin sets up the comparator threshold. Adjust R3 (see
) to
set the comparator trip point for the intended application. The EVM comes with R3 = 31.6 k
Ω
, which
produces a comparator threshold of 80 µA × 31.6 k
Ω
= 2.528 V.
For example, if measuring current across a 10-m
Ω
shunt resistor (and the comparator must be tripped if
an excess of 10 A is measured), then 10 A × 10 m
Ω
= 100 mV, and 100 mV × 20 V/V gain = 2 V. To
achieve a comparator threshold of 2 V, select R3 so that R3 x 80 µA = 2 V. A simple calculation indicates
R3 = 25 k
Ω
.
4
INA301EVM User's Guide
SBOU154 – November 2015
Copyright © 2015, Texas Instruments Incorporated