IDG-500 INVENSENSE, IDG-500 Datasheet - Page 12

• Manufacturer Part Number: IDG-500
• Description: GYRO, DUAL (X+Y) AXIS, +/-500 DEG/S
• Manufacturer: INVENSENSE

Specifications of IDG-500

• No. Of Axes: 2
• Sensor Case Style: QFN
• No. Of Pins: 28
• Supply Voltage Range: 2.7V To 3.3V
• Operating Temperature Range: -20°C To +85°C
• Sensitivity Per Axis: 2mV / ° / S
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.2
CONFIDENTIAL & PROPRIETARY
8.2.5
8.2.1
The gyro is most susceptible to power supply noise (ripple) at frequencies less than 100Hz. At less
than 100Hz, the PSRR is determined by the overall internal gain of the gyroscope. Above 100Hz, the
PSRR is determined by the characteristics of the on-chip low-pass filter. Above 1kHz, the PSRR is
relatively constant except for two narrow frequency ranges corresponding to the resonant frequencies
of the X and Y gyroscopes.
8.2.2
The power supply voltage (VDD) rise time (10% - 90%) must be less than 20ms at VDD (Pin 9, 19) for
proper device operation.
The IDG-500 gyroscope should be isolated from system power supply noise by a combination of an
RC filter that attenuates high frequency noise and a Low Drop Out power supply regulator (LDO) that
attenuates low frequency noise. Figure 4 shows a typical configuration.
The low-pass RC filter should be chosen such that it provides significant attenuation of system noise at
high frequencies. The LDO should be a low noise regulator (<100V/rtHz) that exhibits good noise
rejection at low frequencies.
8.2.3
The scale factor of the gyroscope depends on the amplitude of the mechanical motion and the trim
setting of the internal programmable gain stages. The oscillation circuit controls the amplitude to
maintain constant sensitivity over the specified temperature range. The capacitors connected to Pin 6
(XAGC) and Pin 15 (YAGC) are compensation capacitors for the amplitude control loops.
8.2.4
A built-in Proportional-To-Absolute-Temperature (PTAT) sensor provides temperature information on
Pin 23 (PTATS). The temperature sensor output signal is analog, and has a bias of approximately
1.25V at room temperature, and increases at a rate of 4mV/ºC. The output impedance is nominally
12kΩ and is therefore not designed to drive low impedance loads. If necessary, the output can be
externally buffered with a low offset-drift buffer, and optionally a low-pass filter to minimize noise.
After the demodulation stage, there is a low-pass filter. This filter limits noise and high frequency
artifacts from the demodulator before final amplification. The following graph shows the typical gain
and phase response. The low-pass filter has been designed for a nominally flat gain up to the cutoff
frequency while still achieving a low phase delay at 10Hz and 30Hz.
Design Considerations
Power Supply Rejection Ratio
Power Supply Filtering
Amplitude Control
Temperature Sensor
Internal Low-Pass Filter
IDG-500 Dual-Axis Gyroscope
Product Specification
12 of 25
Figure 4
PS-IDG-0500B-00-06
Release Date: 07/28/09