RDC GX2121, GX2161 Effectively Improve Acceleration Stability of New Energy Vehicles

New energy vehicles have greater acceleration than traditional vehicles, but too fast acceleration is often not friendly to the passenger experience, and the control system of the rotary motor needs to be optimized. How to better control the rotary motor requires a clear understanding of the state of the motor, including the angle and speed of rotation.

Rotation decoding can be categorized into soft decoding and hard decoding. Soft decoding is usually done by MCUs, while hard decoding is done by rotation decoding chips. If the soft decoding scheme is used, the MCU needs to calculate the angle information of the rotor based on the envelope extraction of the sine-cosine signal output from the rotary motor, but this scheme will take up too many resources of the MCU and the accuracy of the output angle will be poor, etc. The MCU can be used to decode the sine-cosine signal from the rotary motor. The use of a dedicated chip for sine-cosine decoding is called hard decoding, and this type of chip is called RDC.

The GXSC GX2121 and GX2161 chips are 10-bit to 16-bit resolution RDCs with an integrated on-chip programmable sine wave oscillator to provide sine wave excitation for the rotary converter. The converter‘s sine and cosine inputs allow for an input of 3.15 Vp-p ±27%. Type II servo loops are used to track the input signals and convert the information from the sine and cosine inputs into digital quantities corresponding to the input angles and speeds. Maximum tracking speed 3125rps.

Product features are described:

1, Ratio Tracking ConversionThe Type II tracking loop is capable of continuously outputting position data with no conversion delay. It also suppresses noise and provides harmonic distortion tolerance for reference and input signals.

2, system fault detection. The fault detection circuitry can detect loss of rotary signal, out-of-range input signal, input signal mismatch, or loss of position tracking. Each fault detection threshold can be individually programmed by the user to be optimized for a specific application.

3. Input signal range. The sine and cosine inputs support differential input voltages of 3.15Vp-p ±27%.

4, Programmable excitation frequency. The excitation frequency can be easily set to multiple standard frequencies in the range of 2kHz to 20kHz.

5, Incremental encoder emulation uses standard A-quad-B format and provides directional output.