L9679P datasheet(245/272 Pages) STMICROELECTRONICS

Part #	L9679P

Description	Automotive advanced airbag IC for mid/high end applications

PDF	272 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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245 / 272 page

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L9679P

Electrical characteristics

271

Figure 71. Deployment drivers diagram

LCSx

Clock Spring Inductance

Design Info

42.9

μH

kL_CS1 –

L_CS2

Clock Spring Coupling

Design Info

0.739

0.903

LEMI

Squib EMI protection

Design Info

7.7

μH

In case of an unsupplied device and shorted deployment pins (e.g. to battery voltage), the dynamic reverse current through

the high side power stage depends on CSSxy.

2. LDEPL could be calculated in the following way:

Non-Clock Spring Loops: LDEPL(max) = LWire(10m*2) + LEMI = (3.6uH/m * 10m) + 7.7uH =43.7uH

Clock Spring Loops: LWire(3m*2) + 2*LCSx + LEMI - (2*kL_CX*SQRT(L_CS1*L_CS2)) = = (3.6uH/m * 3m) + 2 * 42.9uH + 7.7uH -

(2 * 0.739 * 42.9uH) = 40.9uHClock Spring Loops with short to ground

LDEPL(max) = LWire(3m) + LCSx + LEMI = (1.8uH/m * 3m) + 42.9uH + 7.7uH = 56uH.

Table 55. Deployment drivers – DC specifications (continued)

Symbol

Parameter

Comments / Conditions

Min

Typ

Max

Unit

L9679P Datasheet(PDF) 245 Page - STMicroelectronics