SABRE-LL-I datasheet(53/141 Pages) STMICROELECTRONICS

53 / 141 page

SABRE-LL-I

Power bridges

53/141

14.3.2

Parallel configuration (super bridge)

Bridges 1, 2, 3 and 4 can be configured to be used two by two (1 plus 2, 3 plus 4) as one

super bridge thus enabling the driving of loads (motors) requiring high currents. In this

configuration the half bridges will be paralleled and will work as one phase of the super-

bridge just created: the two phases + will become phase + of the newly created super-

bridge while the two phases - will become phase –.

Figure 14.

Super bridge configuration

When this configuration is chosen for bridges 1 (3) and 2 (4), the resulting bridge will use the

driving logic of bridge 1 (3) so for programming it must be used the bridge 1 (3) control and

status bits (direction, PWM, ...): i.e. the used PWM signal will be chosen by

Mtr1SideAPwmSel[1:0] (Mtr3SideAPwmSel[1:0]) bits in SPI.

If the bridges are not configured to be used in parallel, each side of the bridge will use the

PWM selected by the respective MtrXPWMYSel[1:0] bits in the SPI, but if one of the two

drivers is configured as a full bridge only one of the two selected PWM will be used to drive

the motor and this is the PWM chosen for side A.

In order to avoid any problem coming from different propagation times of PWM signals the

anti-crossover dead times are slightly increased when the bridges are paralleled.

14.3.3

Half bridge configuration

Each bridge can be configured to be used as 2 independent half bridges or as 1 super half

bridge (see Figure 15). It is also possible to parallel more than one bridge and use all of

them as a single super half bridge.

Bridge 2 (4)

Super Bridge

Bridge 1 (3)

Bridge 2 (4)

Super Bridge

Bridge 1 (3)

Parallel Full Bridge

SABRE-LL-I Datasheet(PDF) 53 Page - STMicroelectronics