Introduction to current-sense amplifier chip
Current-sense amplifier chip are specialized analog chips designed for high-precision acquisition of loop current signals. They perform the core function of accurate conversion and transmission of current signals in scenarios including industrial measurement and control, power management, and battery systems. Unlike conventional operational amplifiers, these chips integrate high-precision matched gain networks, common-mode rejection circuits and dedicated signal conditioning modules. They enable precise amplification of small sampled signals under a wide common-mode input voltage without requiring complex external calibration circuits, thus significantly simplifying the design process of current acquisition circuits.
Key Advantages of current-sense amplifier chip
The core advantage of current-sense amplifier chip lies in their wide common-mode tolerance capability. Most conventional products support a common-mode input range from several negative volts to over 100 volts, and some industrial-grade models can withstand transient common-mode voltage surges of hundreds of volts. Even when the supply voltage of the measured current loop is far higher than the chip's own operating supply voltage, signal acquisition can still be completed normally. No additional expensive isolation modules are required for level conversion, which greatly reduces the design cost of high-side current detection. Meanwhile, the built-in high-precision matched resistor network controls the gain error within 0.5%, and some laser-trimmed models achieve a gain error as low as 0.1% with temperature drift below 10 ppm/°C. This maintains stable acquisition accuracy across a wide operating temperature range, eliminating the matching error and temperature drift issues caused by external voltage dividing resistors paired with conventional operational amplifiers.
Adaptive Configurations for current-sense amplifier chip
According to differences in detection topology, current-sense amplifiers can be divided into two adaptive configurations: high-side detection and low-side detection. High-side detection models can be directly connected in series to the sampling resistor between the power supply terminal and the load, without breaking the load's ground loop or compromising the grounding integrity of the system, making them highly suitable for scenarios sensitive to ground noise such as motor drives and server power supplies. Low-side detection models are adapted for sampling resistors connected in series between the load and the ground, with the common-mode voltage close to ground potential. Their peripheral circuits are simpler and costs are more manageable, so they are widely used in current monitoring scenarios for consumer electronics and small instrumentation.
Specific Model of current-sense amplifier chip
The INA745x is a digital power monitor that integrates a current-sensing element and is equipped with a 16-bit Δ-Σ ADC specially designed for current-sensing applications. The device can measure current with a full-scale range of ±39.32 A and supports a common-mode voltage range of -0.1 V to +40 V.
The INA745x reports data of current, bus voltage, die temperature, power, electric energy and accumulated charge. It adopts an integrated oscillator with an accuracy of ±0.5% to perform all required calculations in the background, and the integrated temperature sensor achieves a measurement accuracy of ±2.5°C across the full junction temperature range.
With low offset drift and low gain drift design, the INA745x is suitable for precision systems that do not require multi-temperature calibration during manufacturing.
The device supports configurable ADC conversion time ranging from 50 µs to 4.12 ms and sample averaging from 1x to 1024x, which can further reduce noise in measurement data.
Specific Parameters of the current-sense amplifier chip
|
Common-mode voltage (max) (V) |
40 |
|
Common-mode voltage (min) (V) |
-0.1 |
|
Continuous current (max) (A) |
35 |
|
Input offset current (±) (max) (mA) |
6.25 |
|
Input offset current drift (±) (typ) (µA/°C) |
5 |
|
Gain error (%) |
0.1 |
|
Iq (max) (mA) |
1 |
|
Digital interface |
I2C |
|
Resolution (Bits) |
16 |
|
Features |
Alert Function, Bidirectional, Digital Temp Monitor, High precision, Integrated Power Monitor, Integrated Shunt, Low-side Capable |
|
Rating |
Catalog |
|
Operating temperature range (°C) |
-40 to 125 |
Hot Tags: current-sense amplifier chip, China current-sense amplifier chip manufacturers, suppliers, Comparator Chip, Fully Differential Amplifier Chip, Instrumentation Amplifier Chip, Operational Amplifier Chip, PGAs And VGAs Chip, RF Amplifier Chip
