Unipolar stepping motor driver cuts motor control BoM

October 10, 2013 // By Graham Prophet
A series of ICs feature integrated constant current detecting circuits in small package sizes to enable equipment downsizing and reduce component count.

Toshiba's TB67S14x series is available in small package sizes, including the QFN48 package that reduces the mounting area to approximately 1/3 that of equivalent products housed in a HZIP25 package. In addition, the integration of Toshiba’s current detecting circuitry (ACDS4) removes the need for external resistance current detection circuitry, reducing component count.

Home appliances and industrial equipment require high speed and high power motor drives for unipolar stepping motors. The operation of such motors requires a 60V or higher absolute maximum rating to protect against reverse voltage. Typically, a hybrid structure combining motor controllers and high voltage discreet FET (output circuit) is applied, resulting in large package sizes.

These devices have absolute maximum ratings of 80V and 3A and are fabricated in a BiCD 130nm, 80V analogue process. Small packages such as QFN and HTSSOP can be used for system downsizing, while the HSOP package enables flow mounting on a paper phenolic board, which helps to reduce the cost of printed circuit board development. Continuous operation at high current is addressed by using a high-power dissipation package such as HZIP.

Both the TB67S141 and the TB67S142 offer a choice of 2 phase, 1-2-phase and W1-2-phase excitation modes, which corresponds to full- and half-stepping and 1/4 microstepping.

The TB67S149 offers a choice of 2 phase, 1-2 phase, W1-2 phase, 2W1-2 phase, 4W1-2 phase and 8W1-2 phase excitation modes, corresponding to full- and half-stepping, 1/4, 1/8, 1/16 and 1/32 microstepping.

Toshiba Electronics Europe; www.toshiba-components.com