UM1557 Datasheet, PDF (69/111 Pages) STMicroelectronics – The aim of this document is to give the design engineer

UM1557
Paralleling of HSDs
In order to ensure a valid current sense signal and to protect the devices in all previously
described cases, we may add a diode in series to each CS pin (as previously described in
case of monolithic devices – see Section 5.1.1: Monolithic HSDs supplied from different
supply lines).
5.3
Paralleling of outputs
Paralleling output channels should be restricted to exceptional cases. Due to the significant
stray inductance of the wire harness in truck applications, a paralleling of output channels
implies the exposure to a critical high demagnetization energy in case of short circuit
conditions, impacting the component lifetime. Therefore, whenever a paralleled output
configuration is considered, one should add an external freewheeling circuit to protect the
HSD from excessive demagnetization energy.
Other technical subjects linked with paralleling outputs is treated in a future release of this
HWDG.
Doc ID 023521 Rev 2
69/111