ISZ-500 INVENSENSE, ISZ-500 Datasheet - Page 6

• Manufacturer Part Number: ISZ-500
• Description: GYRO, SINGLE (Z) AXIS, +/-500 DEG/S
• Manufacturer: INVENSENSE

Specifications of ISZ-500

• No. Of Axes: 1
• 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 ISZ-500 gyroscope consists of a dual-mass, vibratory MEMS gyroscope. The gyroscope measures
rotation rate about the Z-axis, the axis normal to the surface of the package.
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 Z-
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 structure for detecting angular rate about the Z-axis is fabricated using InvenSense’s
proprietary bulk silicon technology. The structure is 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.
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.
6.4
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 precisely controls the amplitude to maintain
constant sensitivity over the operating temperature range.
CONFIDENTIAL & PROPRIETARY
Overview
Rate Sensor
Oscillator Circuit
Amplitude Control
ZAGC 15
Oscillator
Temperature
PTATS
Sensor
23
Z-Rate
Sensor
ISZ-500 Single-Axis Z-Gyroscope
Charge Pump
Coriolis
Regulator
Sense
CPOUT
12
Product Specification
ISZ-500
Demodulator
Memory
Trim
6 of 24
Figure 1
Low-Pass
Filter
Reference
Auto Zero
VREF
+
22
V
DD
Gain
300k
Output Gain
PS-ISZ-0500B-00-03
Release Date: 07/08/09
Z-OUT
Z4.5IN
14
16
20
24
Z4.5OUT
AZ
Optional
External
Filters