Implementing an H-bridge switch requires the use of four switches, which can each be turned on and off independently of one another. These switches work in tandem pairs. Activating one pair of diagonally-opposed switches will drive the motor in one direction, while activating the other pair will drive the motor in the reverse direction. The speed at which the motor rotates is controlled via the pulse-width modulation (PWM) signal applied.
With four bipolar transistors forming the H-bridge, the TA7291 from Toshiba would become the go-to driver IC for bidirectional motor control for a whole generation of electronic engineers - professional and hobbyist. With a 20 V output voltage rating, it had the capacity to deliver an average driving current of 1 A (and 2 A peak currents). These devices integrated flyback diodes to protect their transistor switches. Having seen implementation in all manner of audio-visual equipment over the course of several decades (most notably in video recorders and CD players), it would be directly referred to in practical electronics books and college lectures.
Building on the impact that the TA7291 had on the global electronics design community, TB67H450FNG is Toshiba’s next generation H-bridge motor driving solution. Though it is encased within a compact 8-pin SOP package (with only 4.8 x 1.75 x 5.8 x mm dimensions), it has operational parameters which are markedly superior to the TA7291 that preceded it. This is due to the BiCD semiconductor process that it uses (which combines bipolar, CMOS, and DMOS technologies). It can deliver an output current of up to 3.5 A and supports PWM frequencies going all the way to 400 kHz. As a result, there is scope for the device to be incorporated into a broad array of different applications. These include small-scale domestic appliances, industrial equipment and handheld power tools.
Toshiba has an unmatched legacy when it comes to H-bridge driver solutions, with the TB67H450FNG writing a new chapter in an ongoing story.
You can read an informative white paper that Toshiba has published on H-bridge motor control below: