Analog Gyros in a Digital Age – How the G150Z Brings Legacy Systems Back to Life

MEMS Gyroscope

In today’s engineering world everything speaks Digital IMU, CAN, Ethernet and High-Speed SPI.
But out in the field – in many legacy military and industrial platforms – there are still thousands of systems that work perfectly and rely on analog gyroscopes.

The system is still mission-capable, the turret rotates, the gimbal is stabilized – but the core sensor that everything depends on has become Obsolete / EOL.

The result:
One small gyro can threaten the availability of an entire system, simply because the manufacturer stopped producing it.

The Problem: An Obsolete Analog Gyro in a System That Must Keep Running

In many stabilization and navigation systems – payload gimbals, stabilized antennas, sighting systems, measurement platforms – the original design is built around:

An analog gyro (often an older gimbal gyro or dedicated rate sensor)
Existing analog control electronics / ADC front-ends expecting an analog voltage or current: 0–5 V, ±10 V, 4–20 mA, etc.
Software and control algorithms tuned and qualified around the noise, bias and dynamic behavior of that specific gyro
Full documentation and qualification (EMC, environmental, reliability) done with that exact sensor

When the original gyro manufacturer announces Obsolete / EOL, several problems appear at once:

Long and unpredictable lead times
High prices for remaining or “last-time buy” stock
Decreasing reliability when using very old parts
Uncertainty about system support over the next 10–15 years

In many cases, the system owner does not want – and sometimes cannot afford – to reopen:

The electronic design
The software and control algorithms
Full military / industrial qualification programs

They “only” need a drop-in replacement for the analog gyro.

Why “Just Go Digital” Is Not Always a Solution

The intuitive reaction is: “Let’s replace it with a modern digital gyro / Digital IMU.”
In reality, that tends to look like this:

Switching from analog voltages to SPI / RS-422 / CAN / Ethernet
Redesigning control boards, adding power converters and changing I/O
Modifying firmware, control algorithms, filters and dynamics
Re-opening full qualification: EMC, vibration, shock, temperature, safety
Risking regressions in a system that has worked in the field for years

In other words – a full redesign project, even though the only real problem is an obsolete sensor.

This is exactly where a modern analog Retrofit solution makes sense:
you keep the existing architecture, control and software – and replace only the gyro.

The Solution: G150Z – An Analog MEMS Gyro for Legacy Systems

The G150Z from Gladiator Technologies is a single-axis (Z-axis) MEMS rate gyro with:

Continuous analog voltage output
Rugged construction and high shock/vibration tolerance
High performance suitable for precision stabilization and navigation

In other words, it is designed for engineers who are looking for an Analog Gyro Replacement / Retrofit rather than a complete redesign.

What does the customer gain by moving to the G150Z?

A modern MEMS sensor – reliable, compact and stable over time
Linear analog output proportional to angular rate
A rugged mechanical design for harsh environments (shock, vibration, humidity)
A wide operating temperature range – suitable for military and industrial use
Ongoing production and availability – a commercial, Non-ITAR product, not a dying legacy part

In Israel, Amironic represents Gladiator Technologies and provides both the sensor itself and engineering support throughout the retrofit process.

Thermal Stability of G150Z Bias

The first figure shows the zero-rate output (bias) of a G150Z unit as a function of temperature for one sample unit (SN1287).
Measurements were taken at three representative temperatures: approximately –40°C, near room temperature (≈ +20°C) and around +60°C.

All three measurement points are within a very narrow band of about –0.03 °/sec to +0.06 °/sec.
In other words, even when moving from very cold to hot conditions, the zero-rate output of the G150Z stays very close to zero.

From a system engineer’s perspective, this means:

The zero (bias) hardly “walks away” over a wide thermal range.
It is easier to maintain good angular accuracy without frequent recalibration or complex temperature compensation tables.
The sensor is especially well suited for military and industrial platforms operating in changing environments – armored vehicles, naval platforms, outdoor payloads, etc.

This directly supports the idea of G150Z as a drop-in upgrade for legacy systems that must remain accurate across a wide temperature envelope.

How It Looks in the Field – A Typical Retrofit Flow

Consider a legacy stabilization system:

A surveillance payload, stabilized antenna, EO/IR gimbal or other precision mechanical platform
Originally equipped with an analog ±5 V gyro designed decades ago
The gyro manufacturer has announced EOL; spare stocks are shrinking and prices are rising

Instead of a full redesign, the system team is looking for:

A replacement that provides a similar analog output, meets the environmental requirements, and allows the system to keep operating for many more years.

Step 1 – Characterizing the Original Gyro

The customer, together with Amironic, collects the relevant information:

Rate range, for example ±150 °/s
Output type: voltage/current, range and scale factor (e.g. 40 mV/°/s)
Environmental requirements: temperature, vibration, shock
Mechanical constraints: envelope, mass, mounting pattern, axis orientation

Step 2 – Matching the G150Z

We then check whether the G150Z:

Provides an equal or higher rate range (for example ±175 °/s instead of ±150 °/s)
Meets or exceeds required noise density and bias stability
Can provide an analog output that suits the existing signal chain, sometimes with a simple gain/scale adjustment
Complies with military-grade environmental requirements (temperature, vibration, shock, humidity)

In many cases it turns out that the G150Z outperforms the old gyro in key parameters, even though the overall system is not redesigned.

Step 3 – Electrical and Mechanical Adaptation

Where needed, Amironic helps define and design:

A mechanical bracket / adapter so the G150Z fits into the existing mechanical envelope
Proper connector and wiring adaptation
Required updates to drawings, BOM and system documentation

Step 4 – Testing and Verification

The upgraded system is then verified through:

Functional testing – stability, accuracy, dynamic response, settling time
Back-to-back comparison versus a system with a still-working original gyro
Environmental tests as needed – vibration, temperature extremes, shock

At the end of the process, the system architecture remains essentially unchanged, but the rate sensor is now modern, available and reliable – and the customer is no longer tied to an obsolete part.

Case Study – Replacing an Obsolete Analog Gyro with the G150Z

In a retrofit project for a legacy military stabilization system, the customer defined clear requirements for a replacement gyro.

Analog output compatibility:

±5 V output
Scale factor around 40 mV/°/s (±5%)
Offset (zero-rate output) close to 0 V with low drift

Sensor performance:

Rate range at least ±150 °/s
Noise density better than 0.02 °/s/√Hz
Bias instability better than 20 °/h
Non-linearity up to 0.1% FS

Environment and endurance:

Temperature –40°C to +70°C
Vibration up to 7 g RMS (20–2000 Hz)
Shock up to 40 g, with short settling time
Warm-up / stabilization time as short as possible

Integration:

Envelope and mass close to the original gyro
Minimal change in wiring and interfaces
Preference for a proven COTS solution from an active manufacturer with a long-term roadmap

After analyzing the original gyro specs and measurements, Amironic proposed using the G150Z-175 from Gladiator Technologies – a single-axis rate gyro with analog output.

To support the decision, we provided an engineering comparison with representative values:

Rate range: ±150 °/s (old) vs. ±175 °/s (G150Z)
Output: analog ±5 V in both cases
Noise density: ~0.02 °/s/√Hz (old) vs. ~0.008 °/s/√Hz (G150Z)
Bias instability: ~25 °/h (old) vs. ~10 °/h (G150Z)
Non-linearity: ~0.2% FS (old) vs. ~0.05% FS (G150Z)
Warm-up time: 5–7 minutes (old) vs. 60–90 seconds (G150Z)
Temperature: –30°C to +60°C (old) vs. –40°C to +85°C (G150Z)
Mass: ~80 g (old) vs. ~45 g (G150Z)

Already at this stage it was clear to the customer that the G150Z was not only compatible, but offered superior performance in most critical parameters: noise, stability, temperature range, mass and robustness.

Electrical Integration – Keeping the Analog Output the Same

The objective was very clear:

Install the G150Z so that, from the controller’s point of view, “nothing has changed.”

Key steps:

Preserve a scale factor close to 40 mV/°/s. No board-level hardware changes were made; instead the customer applied a small software factor (≈1.05) based on measured results.
Perform a zero-rate calibration in the system, using the calibration data supplied with each G150Z.
Feed the G150Z ±5 V output directly into the existing ADC, after verifying that the analog front-end was compatible with the sensor’s lower noise.

Mechanical Integration

Because the G150Z has slightly different dimensions than the legacy gyro, the solution included:

A rugged aluminum bracket/adapter
Preserving the Z-axis direction of the measurement
Using the same mounting holes in the system structure

After vibration testing and FEM checks, the solution was approved with no significant changes to the original mechanical design.

Validation – From Bench to Field

The validation campaign included:

Bench testing of the gyro – measuring noise, bias and linearity across multiple rate levels
Integration tests – measuring axis control loop response (Bode / step response), and back-to-back comparison between a system with the old gyro and a system with G150Z
Field and environmental tests – real mission profiles, temperature extremes, vibration and shock

The results showed equal or improved performance, with very similar behavior from the controller’s point of view, but with a large gain in availability, reliability and maintainability.

Scale Factor Stability of the G150Z over Temperature

The second figure shows the scale factor (sensitivity in mV/°/s) of a G150Z unit versus temperature, again for sample unit SN1287.
Measurements were taken at approximately –40°C, near room temperature and around +60°C.

What is scale factor?
The scale factor is the linear relationship between angular rate and analog output voltage – how many millivolts you get per degree per second.
For example, a scale factor of about 44 mV/°/s means that a change of 1 °/s in rate will produce about 44 mV change in output voltage.

From the data, the scale factor varies only from about 43.68 mV/°/s to 44.03 mV/°/s across the full temperature range – a very small change. This indicates excellent thermal stability of the sensor’s sensitivity.

In practice, this means:

The calibration remains valid when the system moves from very cold to very hot conditions.
There is less need for complex temperature-dependent scale-factor correction tables.
The stabilization / navigation performance remains consistent over the full operational temperature envelope.

Together with the excellent bias stability, this demonstrates that the G150Z offers not only low noise, but also very strong thermal stability – a critical combination for long-term reliability in military and industrial systems.

Short Technical Overview – What Makes the G150Z Special?

Key performance highlights:

Ultra Low Noise: ~0.001 °/sec/√Hz – enables smooth stabilization and accurate angle integration.
Short-Term Bias: ~0.0003 °/sec – very quiet around zero, ideal for servo loops.
Bias Over Temperature: up to ~0.1 °/sec over a wide temperature range – suited to harsh environments.
Bandwidth: around 200 Hz – covers most classic gimbal / stabilization and dynamic applications.
G-Sensitivity: ~0.01 °/sec/g – robust against vibration and linear accelerations without generating significant “false” rate.
Axis alignment: better than 4 mrad – simplifies multi-axis alignment and calibration.

The G150Z is available in several standard rate ranges (e.g. G150Z-100, G150Z-175, G150Z-300)
and in different connector orientations (Side / Top), making mechanical and wiring adaptation to existing platforms much easier.

How Amironic Can Help in Practice

As the representative of Gladiator Technologies in Israel, Amironic offers:

Feasibility checks with no commitment – send us the part number, spec or drawing of your current gyro, and we’ll provide an assessment of compatibility with the G150Z or suggest an alternative.
Engineering support – matching the signal, mechanical form factor, connector orientation and configuration (range, connector, scale).
Supply and logistics – including quality documents, COC, test documentation and support for introducing the part into series production.

Instead of chasing an obsolete gyro and relying on shrinking, aging stock, you can move to a modern, supported solution that will stay with your platform for years to come –
and still speak the same analog language your legacy system understands.

Tags: Gladiator_Technologies