10-bit magnetic single-chip encoder has µA-level current drain

August 01, 2014 // By Graham Prophet
The ultra low power single-chip Hall encoder, iC-TW11 from iC-Haus, allows for an energy-saving 10-bit angle detection and targets for example battery-buffered applications.

With a sampling rate of 10 Hz, average current consumption is typically 3 µA. In standby mode, between measuring cycles, the idle current reduces to approximately 100 nA. In normal operation iC-TW11 supports sampling rates of 4 kHz with an active filter and automatic amplifier gain for 10-bit resolution at maximum accuracy. A measuring cycle can be operated either via the SPI interface or via a separate trigger input by an external event.

A new position value is signalled to the micro controller via an interrupt. The 4-wire SPI interface can be operated at up to 16 MHz clock frequency. The interrupt structure allows a daisy-chain wiring of multiple iC-TW11 devices, and so a controller can capture multiple rotation axes simultaneously.

Typical applications are:

- Battery-operated dynamic speed measurement in power tools

- Position and motor control in mobile robots or aircraft

- Wireless position measuring with an “energy harvesting“ power supply

- Mobile servo motor and stepper motor controls

- Simple 10-bit encoder with adaptive current consumption

- Digital control knob with high resolution and ultra-cap buffering

- Manually adjustable digital potentiometer

- Control knob with pushbutton function through evaluation of the magnetic field strength

At a voltage supply of 3.3 V (±10%) iC-TW11 operates in the extended industrial operating temperature range from -40 to +125°C. The space requirement of the single-chip encoder iC is especially low due to the QFN16 package measuring 4 x 4 mm.

IC-Haus; www.ichaus.com/tw11