IDG-500 INVENSENSE, IDG-500 Datasheet - Page 6

• 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

5. Functional Block Diagram
6. Functional Description
6.1
The IDG-500 gyroscope consists of two independent vibratory MEMS gyroscopes. One detects rotation
about the X-axis; the other detects rotation about the Y-axis.
The gyroscope’s proof-masses are electrostatically oscillated at resonance. An internal automatic gain
control circuit precisely controls the oscillation of the proof masses. When the sensor is rotated about the X-
or Y-axis, the Coriolis Effect causes a vibration that can be detected by a capacitive pickoff. The resulting
signal is amplified, demodulated, and filtered to produce an analog voltage that is proportional to the angular
rate.
6.2
The mechanical structures for detecting angular rate about the X- and Y-axes are fabricated using
InvenSense’s proprietary bulk silicon technology. The structures are covered and hermetically sealed at the
wafer level. The cover shields the gyro from electromagnetic and radio frequency interferences (EMI/RFI).
The dual-mass design inherently rejects any signal caused by linear acceleration. The X-gyro and the Y-gyro
have different resonant frequencies to prevent undesired coupling.
6.3
The oscillator circuit generates electrostatic forces to vibrate the structure at resonance. The circuit detects
the vibration by measuring the capacitance between the oscillating structure and a fixed electrode. The
oscillator circuit switches in quadrature phase with the capacitance measurement in order to vibrate at
resonance.
CONFIDENTIAL & PROPRIETARY
Overview
Rate Sensors
Oscillator Circuit
YAGC 15
XAGC 6
Oscillator
Oscillator
Y-Rate
Sensor
X-Rate
Sensor
IDG-500 Dual-Axis Gyroscope
Coriolis
Coriolis
Sense
Sense
Charge Pump
CPOUT
Product Specification
12
IDG-500
Demodulator
Demodulator
6 of 25
Memory
Figure 1
Low-Pass
Low-Pass
Trim
Filter
Filter
Auto Zero
Auto Zero
+
+
Reference
VREF
22
V
DD
Gain
Gain
Sensor
PTAT
23
Output Gain
Output Gain
PS-IDG-0500B-00-06
Release Date: 07/28/09
X-OUT
Y-OUT
Y4.5IN
X4.5IN
24
1
14
7
16
20
5
X4.5OUT
AZ
Y4.5OUT
Optional
External
Optional
External
Filters
Filters