L9678P datasheet(112/203 Pages) STMICROELECTRONICS

Numer części	L9678P

Szczegółowy opis	Automotive user configurable airbag IC

PDF	203 Pages

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Producent	STMICROELECTRONICS [STMicroelectronics]

Strona internetowa	http://www.st.com

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112 / 203 page

Deployment drivers

L9678P, L9678P-S

112/203

DocID029274 Rev 3

Figure 23. Deployment driver block

6.1.1

Deployment current selection

Deployment current is programmed for all channels using the Deploy Configuration Register

(DCRx) shown in “Deployment Configuration register (DCRx).

If 1.75 A deployment current is selected, the 2 ms deployment time cannot be chosen. If a

SPI command with 2 ms and 1.75 A selection is received, L9678P will discard it and switch

to a 500 µs and 1.2 A selection instead. This misuse is flagged with the CHxDD bit in the

Deploy Status Register (DSR).

6.1.2

Deploy command expiration timer

Deploy commands are received for all channels using SPI communications. Once a deploy

command is received, it will remain valid for a specified time period selected in the Deploy

Configuration Register (DCRx). The deploy status and deploy expiration timer can be read

through the Deploy Status Register (DSRx). The deploy expiration timer is 6 bits and the

maximum time is 500 ms nominal.

L9678P Arkusz danych(PDF) 112 Page - STMicroelectronics