Tronics 
FAQ High performance MEMS Gyros and Accelerometers
All you need to know on GYPRO® and AXO® products lines
General
The main legal basis for controls on dual-use goods is the European Union Dual-Use Regulation, also known as Council Regulation (EC) No 428/2009 and associated legal amendments. This legislation is directly applicable in all European Union countries, including France. As such, GYPRO® and AXO® products are not dual-use products.
GYPRO® and AXO® products are manufactured and tested in France, Europe.
Each sensor is serialized and delivered with a Certificate of Compliance indicating the following test results :
- Scale factor non linearity at room temperature
- Scale factor variation over temperature
- Bias variation over temperature
- RMS noise [1-100Hz] at room temperature for GYPRO® products and noise density for AXO® products.
No, our Gyros and Accelerometers are fully digital with a 24-bit SPI output.
The reliability of GYPRO® products have been assessed by High Temperature Operating Life Test (HTOL) and High Temperature Storage Life Test (HTSL).
The MTBF for operation at 85°C is 270 000 hours (≈ 30 years).
The MTBF for storage at 100°C is 1,700,000 hours (≈ 200 years).
Additional information can be provided upon request.
GYPRO® and AXO® products are silicon-MEMS gyros and as such are not affected by magnetic fields.
For GYPRO® products, even if the sensor is specified over a range of ±300°/s, GYPRO® are capable of measuring above this value up to about ±450°/s. To fulfill export regulation, all GYPRO® sensors have output limitation at ±475°/s.
For AXO® products, the sensor is specified over a range of 14g. Even if the AXO® are capable of measuring above this value, sensors output are restricted below 15g to fulfill export regulation.
For GYPRO® products, Even if the sensor is specified over a range of ±300°/s, GYPRO® are capable of measuring above this value up to about ±450°/s. To fulfill export regulation, all GYPRO® sensors have output limitation at ±475°/s.
For AXO® products, the sensor is specified over a range of 14g. Even if the AXO® are capable of measuring above this value, sensors output are restricted below 15g to fulfill export regulation.
Thanks to the 24 digital output, the scale factor is fixed to 10,000 LSB/°/s during manufacturing for GYPRO® products, corresponding to a resolution of 10-4°/s/LSB, i.e. 0,36 °/h/LSB.
For AXO®, the scale factor is fixed to 500,000 LSB/g during manufacturing, corresponding to a resolution of 2*10-6g/LSB, i.e. 2µg/LSB.
Filtering / Bandwidth / Data rate / Latency
Typical latency is given in respective product datasheet, down to 1ms on the GYPRO3300 and AXO315, ideal for stabilization requirements.
No, the bandwidth and the data rate of GYPRO® and AXO® products are fixed during manufacturing and cannot be changed by the customer. However specific needs can be addressed upon request.
As the ASIC is self-clocked on the drive frequency of the MEMS resonator, the data rate can vary a bit from one device to another due to the dispersion in the MEMS manufacturing process.
For maximum and minimum values, please refer to the corresponding product datasheet.
Integration on printed circuit board (PCB)
GREF capacitor
The typical voltage value for GREF pin is 4,4V.
For reliability reasons, we recommend to use at least a rate voltage of 10V for the GREF capacitor
We recommend to use a tantalum capacitor.
GREF is the reference voltage used for excitation and actuation of the proof masses. If the filtering capacitance is not connected, the noise will increase considerably.
PLL filter (only on GYPRO® products)
The PLL pin voltage range is between 0.15V and 1.65V. This value varies with temperature.
Yes it is possible to use a 4,7µF capacitor even if the optimized value is 5,6µF. In general reducing the capacitor size will increase the PLL Bandwidth which increases the noise contribution, but the difference between these two values is limited.
During factory calibration, each sensor is already temperature-compensated over the operating temperature range. Soldering to the PCB can lead to minor errors in the bias and scale factor over the operating temperature range.
To achieve optimal performances over temperature, it is recommended to perform a new compensation at the system level.
Thanks to the Jlead on the package, AXO® products are less sensitive by PCB mounting.
All the GYPRO® digital pins work on a 5V voltage level, so you need to add a level shifter. For example, the level shifter used on Tronics Evaluation board is a TXB0108PWR.
For AXO® Products, the I/O voltage level of the sensor can be directly adapt from 1.8 to 5V, thanks to the VDDIO pin.
2D model (.dxf) are also available upon request.
Product compatibility
The only difference between GYPRO2300 and GYPRO2300LD is the configuration of the IC. Some filtering stages have been bypassed on the GYPRO2300LD in order to reduce the latency down to 2ms.
The GYPRO3300 has been designed to improve the sensor behavior under strong vibration condition.
No, the IC configuration has been programmed on the OTP (One Time Programmable) memory of the sensor and it not possible to change it anymore.
The answer is yes.
The hardware is compatible, but there are two changes on the pinout, as described below:
CLCK400K is not available on GYPRO3300, but there is no issue if you have connected this pin in your system.
DRY is a digital output which generates a pulse when a new data is available. There is no issue if you haven’t connected this pin in your system.
In term of software, the basic SPI command to read the angular rate data and temperature data are the same. Nevertheless, there are some differences regarding advanced SPI commands (please refer to the product datasheets).