STEVAL-AETKT2V1 Evaluation Kit for High Precision Bidirectional Current Sense Amplifiers User Manual
- June 6, 2024
- ST
Table of Contents
STEVAL-AETKT2V1 Evaluation Kit UM2859 User Manual
Getting started with the STEVAL-AETKT2V1 evaluation kit for high precision bidirectional current sense amplifiers
Introduction
The STEVAL-AETKT2V1 evaluation kit implements bidirectional current sense amplifiers by placing a sense resistor either in the high side or in the low side.
The STEVAL-AETKT2V1 kit consists of a mother board and two different daughter boards for different gain configurations.
TSC21x family implements zero drift technology and is specially designed to accurately measure current by amplifying the voltage across a shunt resistor connected to its input. The voltage drop (Vsense) is then amplified by an amplifier.
Thanks to the use of thin film resistors, TSC21x offers an extremely precise gain and very high CMRR performance.
Moreover, thanks to the possibility of fixing the output common mode voltage through a reference pin, the TSC21x can be either used as unidirectional or bidirectional current sensing amplifier.
Getting started
Overview
- Input common mode voltage: 26 V
- Offset voltage: ±35 μV (±100 μV) max.
- Offset drift: 0.1 µV/°C max.
- Gain drift: 20 ppm/°C max.
- 2.7 to 26 V supply voltage
- Quiescent current: 100 μA max.
- SC70-6 and QFN10 (1.8 x 1.4 mm) package
- Temperature range: -40 to 125°C
- Gain configuration from 50 V/V to 1000 V/V
- RoHS compliant
Shunt resistance
The STEVAL-AETKT2V1 offers the possibility of soldering a shunt resistance directly on the PCB. The board can host standard 2512 package size shunts on 4 W footprint optimized for minimal reading error.
You can choose the appropriate shunt package and value for your own application. If the chosen shunt is not compatible with the footprint, it has be connected outside the evaluation kit.
The selection of the shunt resistor is a tradeoff between dynamic range and power dissipation. Generally, in high current sensing applications, the focus is to reduce as much as possible the power dissipation (I²R) by choosing a shunt with the smallest value.
The recommended shunt value is obtained from the following equation:
Where VoutMax is the maximum output voltage usually equal to the device Vcc or the ADC connected to the output, Vol is the output low swing value for the TSC21x family (in this case, it is 30 mV), Gain is the gain of the selected device (for example, TSC213 has a gain of 50), ERRORgain equals to 1%, Vio represents the input offset voltage (100 µV can be considered for TSC213), Irange is the actual range to be measured.
Note: It is recommended to take a bit smaller shunt value to have some margin and prevent saturation.
The actual current range is calculated by the following equations:
Connection
The STEVAL-AETKT2V1 evaluation kit can be connected to the application design via J1 header
Voltage reference settings
As the TSC21x family devices can measure current in both directions, some voltage reference has to be provided. Voltage reference can be generated directly on the STEVAL-AETKT2V1 evaluation kit by a precision op-amp or by shunt voltage reference. Another option is to use an external reference voltage source. Refer to the following table for proper jumper settings.
Important: Only one jumper at a time can be placed on the kit.
- The reference voltage value can be adjusted by resistor values.
- IC components might be damaged
Schematic diagrams
Bill of materials
Revision history
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