L9945 datasheet(7/151 Pages) STMICROELECTRONICS

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Figure 5 shows an example of P&H1 configuration with NMOS transistor on the High-Side. Refer to this

schematic in order to understand how the external FETs must be mounted with respect to the DRNx/GNSPx/

SNGPx/PGNDx/BATTx pins.

In case of PMOS on the High-Side, refer to Figure 3 in order to understand the DRNx/GNSPx/SNGPx/BATTx pin

connection.

The peak and hold configuration is suitable for driving several types of loads as:

•

Injectors;

•

Fuel pump;

•

Other type of electrovalves and coils that may benefit from peak and hold control.

2.3

H-Bridge

The device can handle up to two H-Bridges. There are two possible configurations which can co-exist:

•

H-Bridge 1: it involves channels 1 (HS), 2 (HS), 3 (LS) and 4 (LS) and can be selected through the

HB1_config bit

•

H-Bridge 2: it involves channels 5 (HS), 6 (HS), 7 (LS) and 8 (LS) and can be selected through the

HB2_config bit

Once an H-Bridge configuration is selected through its config bit, the corresponding output channels are

automatically configured as reported above. The FET type for the High-Side transistors can be selected through

their N_P_config_xx bit.

In case of H-bridge with PMOS on the High-Side, refer to Figure 3 in order to understand how DRNx/GNSPx/

SNGPx/BATTx are mounted with respect to NMOS pin connection.

The H-Bridge configuration is suitable for driving the following types of loads:

•

Brushed DC motors

Note:

When configuring H-Bridge 2, the EN6 input must be set high to enable the output driver.

L9945

H-Bridge

DS12275 - Rev 8

page 7/151

L9945 Datasheet(PDF) 7 Page - STMicroelectronics