Features

• Differential inductive sensing mechanism
• Insensitive to magnetic interference fields
• Robust in oil, water, dust, particles
• Ultra-thin package, 1.8 mm thick
• Thin and low-cost PCB-type target strips/discs

Applications

• Industrial automation
• Stages and X-Y tables
• Assembly / Pick & Place equipment
• Linear motor, voice coil actuator
• Pneumatic/hydraulic actuator
• Machine tools

Description

The PO2300 series encoder kit consists of a sensor element and a PCB-type target. The target is supplied either in the form of a strip for linear applications or a disc/ring for rotational applications.

The sensor-element is a differential transformer structure (similar to an LVDT or a resolver) with the coils integrated on a silicon chip. The electronics to drive the sensor and to treat the sensor signals are integrated in the same chip.The linear target or disk/ring is a PCB with a copper pattern with a period length of 1.2 mm. The copper pattern is covered by a solder-mask, which provides a protection against liquids and against mechanical impact. The PCB-material is easy to “cut to length”. For alternative targets, please contact POSIC.

General specifications and technical drawing

Resolution	0.3 - 150 um
Maximum speed	0.05 - 50 m/s
Airgap range	up to 0.9 mm
Supply voltage	5 V +/- 0.5 V
Supply current	15 mA typ
Temperature	0 - 100°C
Target length	up to 300 mm
Target material	Copper on FR4
Target period	1.2 mm
Therm. exp. coeff.	11 ppm/°C
Output formats	A/B, PWM, AR

Airgap and Rotor Distance

The Air-Gap (AG) is the distance between the glob-top protection layer and the target as shown below.

The Rotor Distance (RD) is the distance between the frontside of the sensor-PCB and the target. Because the frontside (or backside) of the PCB is typically used a mechanical reference for assembly of the sensor into a mechanical system, the Rotor Distance rather than the Air-Gap is used in the specifications.

Output format A quad B

Channel frequency	Up to 500 kHz
Phase shift	90 +/- 45°
Duty Cycle	50 +/- 25%
Hysteresis	1 increment
Index pulse (I)	Synchronous to 1 B-pulse

Output format PWM

Repetition frequency	500 kHz ± 20%
Resolution	below 1 um
Pulse width range	10 - 90%
Rotor Distance	1.0 - 1.4 mm

The two PWM output signals are redundant: PWM2 = NOT(PWM1)

Output format Analog Ratiometric

Bandwidth	1 kHz
Resolution	below 1 µm
Output signal range	0.5 - 4.5 V (with VDD = 5.0 V)
Rotor Distance	1.0 - 1.4 mm

Rotor Distance, resolution and speed

The maximum Rotor Distance as a function of resolution and maximum speed is listed in Table 1. These parameters are programmable ex-factory (see ordering information below).

Sensor orientation

The sensor is programmed ex-factory for longitudinal or orthogonal orientation with respect to the target strip, as shown in the figure to the right.