1.3 Full Bridge Mode

In Forward and Reverse Full Bridge modes, three outputs drive static values while the fourth is modulated by the input data signal. The mode selection may be toggled between forward and reverse by toggling the MODE[0] bit of the CWGxCON0 register while keeping the MODE[2:1] bits static, without disabling the CWG module. When connected, as shown in Figure 1-3, the outputs are appropriate for a full bridge motor driver. Each CWG output signal has independent polarity control, so the circuit can be adapted to high-active and low-active drivers.

Figure 1-3. Example of Full Bridge Application

In Forward Full Bridge mode (MODE = ‘b010), CWGxA is driven to its Active state, CWGxB and CWGxC are driven to their Inactive states, and CWGxD is modulated by the input signal, as shown in Figure 1-4.

In Reverse Full Bridge mode (MODE = ‘b011), CWGxC is driven to its Active state, CWGxA and CWGxD are driven to their Inactive states, and CWGxB is modulated by the input signal, as shown in Figure 1-5.

In Full Bridge mode, the dead-band period is used when there is a switch from forward to reverse or vice versa. This dead-band control is described in the Dead-Band Control section, with additional details in the Rising Edge and Reverse Dead Band and Falling Edge and Forward Dead Band sections.

Important: Steering modes are not used with either of the Full Bridge modes.
Figure 1-4. Example of Full Bridge Forward Mode Output
Figure 1-5. Example of Full Bridge Reverse Mode Output
Note: A rising CWG data input creates a rising event on the modulated output.