In applications such as battery management systems (BMS), motor drive control, power management, automotive electronics and industrial automation, precise current monitoring is a key factor in ensuring system safety and improving energy efficiency. Mingjiada Electronics is now supplying the Texas Instruments (TI) INA194 current sense amplifier in large quantities, with ample stock and competitive pricing to help engineers rapidly complete high-precision current sensing designs.
I. Product Overview
The INA194 is part of TI’s INA19x series of current shunt monitors and is a voltage-output current sense amplifier. It detects the voltage drop across a shunt resistor and operates stably over a wide common-mode voltage range of −16 V to +80 V, independent of the device’s own supply voltage. The INA194 is housed in a space-saving SOT-23-5 package and supports single-supply operation (2.7 V to 18 V) with a maximum supply current of just 900 μA, making it ideal for high-density PCB designs and power-sensitive applications.
II. Specifications
Common-mode voltage range: −16 V to +80 V
Gain: 50 V/V (fixed)
Bandwidth: up to 500 kHz
Supply voltage: 2.7 V to 18 V (single supply)
Quiescent current (Iq): 700 μA (typical) / 900 μA (maximum)
Input bias current (Ib): 8 μA
Input offset voltage (Vos): 500 μV
Temperature drift of input offset voltage: 2.5 μV/°C
Slew rate (SR): 1 V/μs
Common-mode rejection ratio (CMRR): 94 dB
Noise density: 40 nV/√Hz @ 1 kHz
Operating temperature range: −40 °C to +125 °C
Package: SOT-23-5
III. Key Features
1. Wide common-mode voltage range (−16 V to +80 V)
The INA194 is capable of accurately detecting the voltage drop across a shunt resistor over a wide common-mode voltage range of −16 V to +80 V, regardless of the device’s supply voltage. This feature enables it to adapt to a variety of complex circuit environments, including high-voltage bus systems and applications involving negative voltage transients.
2. High Accuracy and Low Error
The INA194 has a maximum error of just 3.0% across the entire temperature range, an input offset voltage of only 500 μV, and a temperature drift as low as 2.5 μV/°C. This low-error characteristic is crucial for applications requiring precise current monitoring, such as battery management systems and power management modules.
3. 500 kHz High Bandwidth
A bandwidth of up to 500 kHz enables the INA194 to respond rapidly to transient changes in current, making it suitable for current control loops requiring fast dynamic response, such as switch-mode power supplies and motor control applications.
4. Low Quiescent Current
With a maximum quiescent current of just 900 μA, the device helps reduce system power consumption and improve energy efficiency, making it particularly suitable for power-sensitive applications such as portable devices and battery-powered systems.
5. Complete Current Sensing Solution
The INA194 integrates complete current sensing functionality; high-side or low-side current measurement can be achieved with just a single external shunt resistor, significantly simplifying circuit design.
IV. Typical Application Scenarios
1. Battery Management Systems (BMS)
In electric vehicles, portable devices and energy storage systems, the INA194 can accurately measure battery charge and discharge currents to enable State of Charge (SOC) monitoring and State of Health (SOH) assessment. In lithium-ion battery charge management systems, high-precision current monitoring and state-of-charge estimation can be achieved by selecting appropriate sampling resistors and gain settings.
2. Motor Control and Drive
The INA194 can be used to monitor operating currents in motor drive circuits, ensuring that motors operate within safe working limits. In industrial automation applications such as industrial robots, CNC machine tools and conveyor belt systems, it provides real-time current feedback to help optimise motor performance and prevent overloads. Its 500 kHz bandwidth makes it particularly well-suited for monitoring the health of DC motors.
3. Power Management and Power Monitoring
In power management systems, the INA194 can monitor load current in real time, working in conjunction with a microcontroller to implement functions such as overcurrent protection, overvoltage protection and short-circuit protection. In applications such as power management for data centre servers and power monitoring for telecommunications equipment, the INA194’s low power consumption and high precision make it an ideal choice.
4. Automotive Electronics
The INA194’s wide temperature range (−40°C to +125°C) and high reliability meet the stringent requirements of automotive electronics. Its AEC-Q100-certified version (INA194A-Q1) is particularly suitable for automotive applications such as body control modules and hybrid/electric vehicle powertrains.
5. Other Applications
Furthermore, the INA194 is widely used for current monitoring in products such as welding equipment, laptops, mobile phones, battery chargers and telecommunications equipment.
V. Design Considerations
Shunt Resistor Selection: The resistance value of the shunt resistor must strike a balance between measurement accuracy and power dissipation. For example, for a maximum current of 5 A, a 0.01 Ω shunt resistor may be selected; for a charging current of 2 A, a 0.05 Ω shunt resistor can limit the voltage drop to within 100 mV.
Gain Setting: The INA194 provides a fixed gain of 50 V/V. If a voltage drop of 50 mV occurs across the shunt resistor, the INA194 amplifies this to an output of 2.5 V, facilitating subsequent ADC sampling.
PCB Layout: The signal path length from the shunt resistor to the INA194 input should be kept as short as possible to minimise the likelihood of picking up interference. A filter may be added at the input to remove high-frequency noise.
Bidirectional Current Monitoring: For applications requiring monitoring of bidirectional charging and discharging currents, a bidirectional monitoring circuit can be configured by connecting the REF pin to a reference voltage (e.g. 2.5 V).
VI. Mingjiada’s Supply Advantages
As a specialist supplier of electronic components, Mingjiada Electronics currently stocks the INA194 current sense amplifier in large quantities, offering the following models:
INA194AIDBVR – 16V to 80V, 500kHz current sense amplifier
We promise:
Adequate stock on hand to ensure timely delivery
Genuine factory products with a 100% quality guarantee
If you require INA194samples, a quotation or wish to place a bulk order, please feel free to contact Mingjiada Electronics at any time!
Tags: INA194AIDBVR, INA194AIDBV, INA194AIDB, INA194AID, INA194AI, INA194A, INA194
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