The H-bridge driver has been around for a long time. It presents engineers with a relatively simple way of delivering bidirectional motor control, with the direction of the motor’s rotation being changed by just swapping the polarity of the supply applied to it. The advent of fully integrated versions brought greater convenience than with the early discrete arrangements. Through the 1970s and 1980s these ICs grew in popularity. They were used in huge numbers to drive the capstans of audio cassette recorders, as well as the front loading mechanisms of video tape recorders - with the 20 V rated Toshiba TA7291 H-bridge driver being sold in huge quantities over this period specifically for such purposes. Then, during the 1990s it would be pivotal to CD player designs, enabling the disk tray to move in and out of the machine. Even today, it remains revered by much of the international maker fraternity.
As the needs of the electronics industry have evolved, so has the driver technology that supports it. The TA7291 has now been supplanted by the TB67H450FNG driver IC. This device employs Toshiba's proprietary high-voltage BiCD process, which allows an output voltage of up to 50 V to be supported and delivery of currents reaching 3.5 A. Additional functionality has been included, such as the necessary pre-driver stages, in order to keep the total system component count down and minimize the coding overhead. It does all this while still taking up considerably less board real estate than its predecessor, being housed in a compact 8-pin SOP package format. Under-voltage lock-out, thermal shutdown and over-current protection mechanisms are all included to ensure ongoing operational reliability. Among the applications in which it proves popular are printers, household appliances and robotic systems, being used to control stepper motors and in some cases BLDCs.
A white paper on the principles of H-bridge motor control has been published by Toshiba. It can be downloaded below: