CT130 – The First True Z-Axis Sensitive TMR Sensor

As the industry’s first true Z-Axis sensitive TMR sensor, Crocus’s CT130 advances today’s applications with best-in-class SNR, low temperature drift, stable offset, and low power.

The Incumbent: “Legacy” Hall Element and Hall Sensor

Hall Effect solutions have historically been a preferred solution, as an Element or in the Sensor format.

The Hall Element (a raw sensor) is the most cost-effective Hall device. Both the Element and the Hall Sensor (element plus ASIC and other circuitry to amplify the signal and control deviations) have advantages, but come with drawbacks. While the Hall Element is inexpensive, it is also noisy, suffers from bad temperature coefficient (tempco), poor offset variability, and requires amplification. The Hall Sensor is quieter, features adjustable gain, better tempco and offset control, and integrates correction and features. Its significant downsides are the complexity of the chip and the added cost.

Applications

Applications designed with Hall Elements or Sensors are primarily price-point choices that come down to Total Cost of Ownership vs. Product Performance Targets. In general, both solutions serve the same broad applications:

With position sensing, a magnet in motion needs to be located by the system. For example, in position sensing for motor control the requirement is for linear motion detection and end of travel applications.

In current sensing or Core-based sensing, there’s a ring around the copper and the sensor measures from a position inside the ring. Finally, sensing is required for Optical Image Stabilization (OIS) and auto-focus in smartphones.

The Compromise

With each of the main types of Hall Elements (GaAs, InAs, InSb and Silicon), there is a compromise between the sensitivity and the temperature characteristics. In other words, customers must decide whether they want the highest sensitivity possible or the best thermal performance.

If you needed OIS in a cell phone application, you’d be dealing with fairly normal temperature rings, so you’d opt for higher sensitivity. But sensing in any extreme temperature condition would require more thermal performance at the cost of  sensitivity. You simply can’t have both.

The Solution

As the industry’s first true Z-Axis sensitive TMR sensor, Crocus’s CT130 advances today’s applications with best-in-class SNR, low temperature drift, stable offset, and low power. For the first time, TMR sensors have the same Z-axis of sensitivity as Hall, making it a simple transition to the advantages of TMR.

CT130 does not require a flux concentrator to shape the magnetic field in the sensor’s axis of sensitivity, meaning no hysteresis, no need for a reset function, no additional cost of a larger PCB.

In addition, the die is not vertically mounted, delivering a small footprint and standard packaging. Finally, it is compatible with Crocus standard manufacturing process, providing extremely high volume capability.

The Bottom Line

With CT130, there’s no longer a trade-off between sensitivity and temperature. You get all of the advantages of TMR’s stable offset and temperature performance, with a high sensitivity Z-Axis.

Appendix:

CT130 Product Specification

Features

  • High Sensitivity: ~0.75 mV/V/mT
  • Wide Operating Field: ±150 mT
  • Linearity Error : <0.5%
  • Hysteresis Error: As low as 20 µV/V
  • Coefficient of Sensitivity: -1000 ppm/°C
  • Coefficient of Offset: 2.7 µV/V/°C
  • Temperature range: -40°C to +125°C
  • Package Options:
    • DFN-6, 1.50 ´50 ´ 0.45 mm

Applications

  • 1D Linear Sensing in Z-Axis
  • Position Sensing – Motor Control, Encoders
    • Minimizes duty cycle deviation when switching between north and south poles.
    • Large VOUT VOFFSET reduces duty cycle deviation.
    • Improves motor rotation efficiency.
    • Stable performance over temperature.
  • Current Sensing
    • Repeatable and low offset
    • Low and Linear temperature drift
    • Easy to compensate for <10ppm/C
    • Low lifetime drift
    • High SNR
    • Low noise and high sensitivity
  • Optical Image Stabilization and Autofocus for Camera Modules
    • Repeatable and low offset
    • Low and Linear temperature drift
    • Easy to compensate for <10ppm/C
    • Low lifetime drift
    • High SNR
    • Low noise and high sensitivity
    • Low power consumption

Share:

Facebook
Twitter
Pinterest
LinkedIn
On Key

Related Posts

CT405x: Contactless Sensor Performance

Crocus Technology has expanded its contactless current sensing product offering with two new contactless, coreless current sensors CT4051 and CT4052. These contactless sensors that measure

Keeping EVs Safe

As EV adoption continues to outpace even the most optimistic projections, the focus has been on the range, efficiency – and increasingly, the safety –

CT40x: Redefining Sensor Performance

CT40x: Redefining Sensor Performance

The demand for higher performance in industrial applications will most likely lead to a replacement of Hall effect sensors by…TMR sensors, which in turn will

×