L9678P datasheet(31/203 Pages) STMICROELECTRONICS

部品番号	L9678P

部品情報	Automotive user configurable airbag IC

PDF	203 Pages

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メーカー	STMICROELECTRONICS [STMicroelectronics]

ホームページ	http://www.st.com

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DocID029274 Rev 3

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L9678P, L9678P-S

Start-up power control

202

4.3.4

VDD5 linear regulator

The VDD5 linear regulator provides 5 V system voltage derived directly from battery line

with an external power transistor to reduce integrated circuit power dissipation. This voltage

rail is used in case a 5 V micro-controller is adopted. The stability of the regulation loop is

guaranteed by use of a small external capacitor. Current limitation is provided by means of

controlling output current on BVDD5 pin. The external pass transistor gives the flexibility to

easily address different current loads in case of different micro-controllers. The VDD5

regulator is enabled in the ACTIVE mode and continues operation in the PASSIVE mode

using power from energy reserve. VDD5 supply is monitored for system reset (see Power

On Reset and Reset in Section 4.4); voltage monitoring is based on a second redundant

bandgap voltage reference.

Figure 14. VDD5 control behavior

L9678P データシート(PDF) 31 Page - STMicroelectronics