AS5311 Linear Encoder IC

Description

The AS5311 is a single-chip IC with integrated Hall elements for measuring linear or rotary motion using multi-pole magnetic strips or rings. This allows the usage of the AS5311 in applications where the Sensor IC cannot be mounted at the end of a rotating device (e.g. at hollow shafts). Instead, the AS5311 is mounted off axis underneath a multi-pole magnetized ring or strip and provides a quadrature incremental output with 256 pulses per pole period at speeds of up to 0.65 meters/sec. A single index pulse is generated once for every pole-pair at the index output. In addition, a digital output is available providing 12-bit absolute information within one pole-pair, resulting in a resolution of 0.488 µm from 0 - 2 mm.

The absolute output is available over a serial interface and on a PWM output.

The magnet pole pair length is 2.0mm (1.0mm north pole / 1.0mm south pole).

The AS5311 is available in a small 20-pin TSSOP package and specified for an operating ambient temperature of -40° to +125°C.

Ordering Guideline

Key Features

• High resolution down to 488 nanometers
• Magnetic pole pair length: 2mm
• 256 pulses / 1024 positions per magnetic period
• 1 index pulse per pole-pair
• Linear movement measurement using multi-pole magnetic strips
• Circular off-axis movement measurement using multi-pole magnetic rings
• 3.3V or 5.0V operating voltage
• Extended diagnostic features for magnetic field strength detection

Applications

The AS5311 is ideal for high resolution linear motion and off-axis rotation measurement in applications such as

• micro-actuator feedback
• servo drive feedback
• electrical motors
• robotics
• replacement of optical encoders

Block Diagram