L9678P datasheet(151/203 Pages) STMICROELECTRONICS

No. de pieza	L9678P

Descripción Electrónicos	Automotive user configurable airbag IC

PDF	203 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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DocID029274 Rev 3

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L9678P, L9678P-S

Safing logic

202

Figure 49. Safing engine diagnostic logic

A configurable mask for each internal ARMxINT signal is available for all of the integrated

deployment loops (refer to ARMx assignment registers (LOOP_MATRIX_ARMx) on

page 97). The un-masked ARMxINT signal for each loop will enable the respective loop

drivers (refer to Figure 21).

Activation of VSF (regulation rail for High Side Safing FET) occurs upon ARMxINT or

FENH/FENL, depending on SPI configuration (refer to Figure 17). Actual High Side Safing

FET activation still requires microcontroller signal.

L9678P is able to provide arming signals to external deployment loops by means of the

discrete output ARM pin. The ARM pin can either output an arming signal generated by the

integrated safing engine or an arming signal made by the combination of FENH and FENL

input signals, coming from external safing logic.

Figure 50. ARM output control logic

L9678P Datasheet(PDF) 151 Page - STMicroelectronics