Battery conversion and precise medical ECG detection! Dajiqun launches amplifier TPA1287

Advantages of TPA1287 product

1.High common mode rejection ratio

In the current detection application of battery formation, fluctuations in battery voltage often affect the sampling results, resulting in deviations in the final collected voltage and current data. The high common mode rejection ratio of the input stage of the signal amplifier can effectively reduce the interference caused by the common mode noise of the previous stage. The common mode rejection ratio of TPA1287 is 120dB (@ G=100, Min), 138dB (@ G=100, Typ), and it supports a wide voltage supply from 4V to 36V, expanding the common mode input range. The wide input voltage range and rail to rail output capability allow the signal to fully utilize the power supply rail, enabling it to operate reliably in different environments.

2. High precision and low drift

Accurate detection is crucial in applications such as industrial control and pressure sensing. TPA1287 has extremely low gain error (± 0.05%, @ G=1, Max) and gain temperature drift (2ppm/° C @ G=1, Max); 30ppm/° C @ G>1, Max), as well as extremely low offset voltage (± 40 ± 240/G μ V, Max) and offset temperature drift (± 0.2 ± 0.3/G μ V/° C, Max), ensure high accuracy and temperature stability in voltage and current detection.

Taking the current sampling with a sampling resistance of 0.5m Ω and 100A in battery conversion applications as an example, the effective signal is 50mV, and CMRR is calculated with a minimum value of 120dB. Considering the voltage variation range of 0V~5V, the accuracy impact caused by Vos variation is 5uV/50mV=0.01%; Considering the calibration at room temperature, only the influence of temperature drift is taken into account. The impact of Vos temperature drift at ± 10 ° C on system accuracy is (0.2uV/° C * 10 ° C)/50mV=0.0025%, and the impact of gain error temperature drift (G>1) on system accuracy is 30ppm/° C * 10 ° C=0.03%.

3. High impedance and low noise

Compared to ordinary operational amplifiers, instrumentation amplifiers also have high impedance and low noise characteristics, providing accuracy advantages for collecting high internal resistance signal sources, such as human bioelectric signals and bridge signals. Under the condition of G=10 gain, the input voltage noise of TPA1287 is (@ 1kHz), and the input impedance is at the level of G Ω. In addition, TPA1287 has a low bias current (10nA), which can reduce the impact on the input signal; The flexible gain configuration enables the instrument amplifier to amplify signals of different amplitudes; High bandwidth (1.2MHz @ G=1) can also achieve fast response to signal changes and timely transmit detection signals to post-processing.

TPA1287 Product Features

• Supply voltage: 4.0V~36V
• Low input voltage noise: 15nV/√ Hz (@ f=1kHz, G=10)
• Low offset voltage: ± 10 μ V (Typ)
• Low offset voltage temperature drift: ± 0.2 ± 0.3/G μ V/° C (Max)
• Low static current: 1.6 mA (Typ)
• High bandwidth: 1.2 MHz (@ G=1, Typ)
• Gain error: ± 0 05%（@G=1，Max）
• Gain error temperature drift: 2ppm/° C (@ G=1, Max)
• High common mode rejection ratio CMRR: 138dB (@ DC, G=100, Typ)
• Encapsulation: SOP8, MSOP8

TPA1287 Typical Applications

In industries such as industrial control and medical devices, high common mode rejection ratio and low-noise detection circuits are needed to amplify the collected signals. For example, in the current sampling application of battery formation, a higher common mode rejection ratio can reduce the sampling error caused by battery voltage changes; The front-end signal of medical electrocardiogram (ECG) is weak, and the internal resistance of the signal source is high, requiring high input impedance and low-noise amplifiers for signal amplification. Therefore, instrumentation amplifiers have become the preferred choice for similar applications. TPA1287 relies on its low noise (@ 1kHz, G=10) and high common mode rejection ratio（ 138db@G =100， Typ）、 Low power consumption (1.6mA, Typ), high input impedance, low temperature drift and other characteristics make it an ideal choice for high-precision detection applications. TPA1287 only requires an external resistor to set any gain between 1 and 1000. The package includes MSOP8 and SOP8 to meet the selection requirements.