L9788 datasheet(131/264 Pages) STMICROELECTRONICS

Part #	L9788

Description	Multifunction IC for automotive engine management system

PDF	264 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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131 / 264 page

DS12308 Rev 4

131/264

L9788

Pre-drivers - IGNITER IGN[1:6]

263

10.4

Open load

When IGNx pre-driver is enabled HIGH, if IGNx current is lower than OL current detection

Ith_OL_IGN for a filter time, open load fault is detected and the driver is not disabled. Open

load function can be disabled by a MSC bit. Open Load fault is latched until

Read_Diag_cmd action. OPL threshold is selectable between 2 values, the default

(between 0.4 and 0.8mA) and a lower one.

OPL threshold reduction is available just in low current limitation condition, so when

OL_RED and IGN_CURRENT_CFG (CONFIG_REG2 D4) bits are both high.

10.5

Error in driver status

Refer to Section 7.1.3.

Figure 54. Low-side drivers ON diagnosis timing diagram at open load

GADG0512161627PS

IGNx_CMD

NO Fault

Open load

Open load fault happened

Filter time for IGN

Enabled HIGH

Enabled LOW

Read_Diag_CMD

Diag_fault

I_IGNx

Ith_OL_IGN

Driver status

IGNx_ol

L9788 Datasheet(PDF) 131 Page - STMicroelectronics