AS5134 Rotary Encoder IC for Brushless DC Motors

Description

The AS5134 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360°.
It is a system-on-chip combining integrated Hall elements, analog front end and digital signal processing in a single device.

To measure the angle, only a simple 2-pole magnet rotating over the center of the chip is required.

The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 8.5 bit = 360 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal.

In addition to the angle information, the strength of the magnetic field is also available as a 6-bit code. Data transmission can be configured for 1-wire (PWM), 2-wires (DCLK, DIO) or 3-wires (DCLK, DIO, CS).

A software programmable (OTP) zero position simplifies assembly as the zero position of the magnet does not need to be mechanically aligned.

A Power Down Mode together with fast startup- and measurement-cycles allows for very low average power consumption.

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Key Features

• 360° contactless angular position encoding
• 2 digital 360 step (8.5 bit) absolute outputs:
  • Serial interface and
  • Pulse width modulated (PWM) output
• User programmable zero position, sensitivity
• High speed: up to 82,000rpm
• Direct measurement of magnetic field strength allows exact determination of vertical magnet distance
• Incremental Outputs ABI Quadrature: 90ppr, step direction: 180ppr, fixed pulse width 360ppr
• BLDC Motor Commutations Outputs UVW, selectable for 1,2,3,4,5,6 pole pairs
• Daisy-Chain mode for cascading of multiple sensors
• 9-bit multiturn counter
• Low power mode with fast startup
• Wide magnetic field input range: 20 – 80mT
• Wide temperature range: -40°C to 140°C
• Small Pb-free package: SSOP-20

Applications

• Contactless rotary position sensing
• Rotary switches (human machine interface)
• AC/DC motor position control
• Brushless DC motor position control

Block diagram for AS5134 Rotary Encoder IC for Brushless DC Motors