Highly Integrated AFE GX1148 Hardware and Software 100% Replacement of ADS1148 for Inverter Applications

Inverters are power control devices that control AC motors by changing the frequency of the motor‘s operating power supply. Inverter in the operation process, the need for real-time monitoring of the input and output current and voltage signals, in order to achieve accurate control and protection of the motor, the AFE can be from the current sensor and voltage sensor analog signal is converted to a digital signal, provided to the inverter control chip for processing. This paper focuses on the application of a GX1148 chip hardware and software 100% replacement of ADS1148 in the inverter.

The GX1148 is a low-cost, low-power, highly integrated complete analog front-end, which internally contains 8-channel analog switches, a low-noise PGA, a low-temperature-drift reference source, a high-matching IDAC and a high-precision 16-bit Ʃ-Δ-type ADC. The 16-bit resolution of the GX1148 enables high-precision measurements that can accurately reflect small changes in current and voltage. Its low-noise characteristics help to acquire high-quality signals in complex electromagnetic environments and reduce measurement errors. At the same time, the Programmable Gain Amplifier (PGA) automatically adjusts the gain according to the size of the input signal to ensure that the signal input to the ADC is in the optimal range, further improving measurement accuracy.

GX1148 chip features:

- Number of channels: 8 single-ended / 4 differential pairs

- Output rate: 2kSPS

- Continuous conversion power: 2mW

- Highly integrated:

　‘ Integrated internal reference: temperature drift 20ppm / ℃ (Maximum)

　‘ Programmable differential amplifier (integrated high impedance PGA)

　‘ Integration of 2 high matching IDACs

　‘ Integrated Bias voltage and wire break detection

　‘ Integrated internal temperature sensor

- Supports 50/60Hz simultaneous suppression

- Single-cycle build-up and automatic channel scanning

- Support SPI CRC check

- Digital power supply: 2.7V~5.25V

- Analog power supply: Unipolar (2.7V~5.25V) & Bipolar (±2.5V)

- Package: 9.7mm x 4.4mm TSSOP (28pin)

- Operating temperature range: -40°C to +125°C