AS5305 Integrated Hall IC for linear and off-axis rotary motion detection

Revision 1.4

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General Description

The AS5305 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 AS5305 in applications where

the Sensor IC cannot be mounted at the end of a rotating

device (e.g. at hollow shafts). Instead, the AS5305 is

mounted off-axis underneath a multi-pole magnetized ring

or strip and provides a quadrature incremental output with

40 pulses per period at speeds of up to 20m/sec.

Using, for example, a 32pole-pair magnetic ring, the

AS5305 can provide a resolution of 1280 pulses/rev, which

is equivalent to 5120 positions/rev or 12,3bit. The

maximum speed at this configuration is 9375 rpm.

The default pole pair length is 4mm (2mm north pole / 2mm

south pole). However, the chip accepts a wide range of

multi-pole magnetic strips or rings with pole pair lengths

between 2.26 and 5.91mm and magnetic field strengths

down to 5mT. The pole pair length can be adjusted by

programming. A minimum pole pair length of 2,26mm

allows a resolution of 14,125 m per position step.

In addition to the multi-pole high-resolution track, the

AS5305 can read a second multi-pole reference track that

generates a single or multiple reference index pulse per

revolution, for absolute position identification.

The AS5305 is available in a small 20-pin TSSOP package

and specified for an operating ambient temperature of

-40° to +125°C.

Figure 1: Two differ ent configurations of AS5305 with single or

double tr ack multipole ring magnet

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Benefits

•

Complete system-on-chip

•

High reliability due to non-contact sensing

•

Extended temperature range

•

Suitable for the use in harsh environments

•

Robust against external magnetic stray fields

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Key Features

•

High speed, up to 20m/s

•

Down to 14 m resolution per position step

•

User programmable pole length

•

Single index pulse per revolution for absolute position

measurement using a second magnetic track

•

40 pulses per magnetic period.

•

Linear

movement

measurement

using

multi-pole

magnetic strips

•

Circular off-axis movement measurement using multi-

pole magnetic rings

•

4.5 to 5.5V operating voltage

•

Magnetic field strength indicator

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Applications

The AS5305 is ideal for high speed linear motion and off-

axis rotation measurement in applications such as

•

electrical motors

•

X-Y-stages

•

rotation knobs

•

industrial drives

Figure 2: AS5305 with magnetic multipole str ip

for linear motion measur ement

DATA SHEET

PRELIMINARY FACT SHEET

AS5305

Integrated Hall IC for

Linear and Off-Axis Rotary Motion Detection

PRELIMINARY FACT SHEET