Ultra-small resolver converter

Citation

(2000), "Ultra-small resolver converter", Aircraft Engineering and Aerospace Technology, Vol. 72 No. 1. https://doi.org/10.1108/aeat.2000.12772aad.007

Ultra-small resolver converter

Keywords DDC, Resolver converters

DDC's new RD-19230 low-cost, 16-bit resolver-to-digital converter (Plate 1) measures only 10mm x 10mm and is said to be ideal for high-performance industrial and commercial positioning systems. Using the analog output from electromechanical resolvers, it provides a 16-bit digital word representing shaft angle, a velocity output and encoder emulation.

Plate 1 DDC's new RD-19230 low-cost, 16-bit resolver-to-digital converter measures only 10mm x 10mm

The single CMOS custom monolithic chip merges precision analog circuitry with digital logic to form a complete high-performance tracking converter with an accuracy of 2.3 arc minutes. For flexibility, the RD-19230 offers user-programmable encoder emulation, resolution, bandwidth, tracking rate, and velocity scaling.

The RD-19230 is thought to be ideal for industrial and commercial position applications such as servo motor controls, antenna positioning, aircraft position feedback systems, machine tool and robotic positioning controls, and manufacturing process control systems.

An internal encoder emulation feature (with independent resolution control) enables the RD-19230 to emulate incremental optical encoder output signals enabling encoder-based systems to easily interface with the converter's output. Differential resolver inputs allow for easy filtering in noisy environments.

The converter's ±4V velocity output eliminates the need for a tachometer, and its full-scale value can be set with a single resistor. Velocity scaling, reversal error, and offset parameters may be externally trimmed for applications requiring tighter specifications than are the norm.

Normally, as little as six degrees of resolver phase shift can cause accuracy problems in 16-bit R/D converters. However, the RD-19230's synthesised reference not only eliminates errors caused by quadrature voltage, but ensures accurate operation with a phase shift of up to 45°.

The RD-19320 has a dual bandwidth feature which enables users to switch the resolution "on the fly" between 10-, 12-, 14-, or 16-bits with minimal upset to velocity and position information. Dual bandwidth and switch-on-the-fly resolution are ideal features for applications requiring high resolution with a setting time that is faster than the resolution will permit.

The RD-19230 operates over -40°C to +85°C and is contained in a 64-pin plastic quad flat pack.

Details available from: Data Device Corporation (DDC). Tel: +44 (0)1635 40158; Fax: +44 (0) 1635 32264.