L9634

18/36

Figure 17. Short-to-Battery Diagnostic Diagram

4.12 Open Circuit and Short to Ground Diagnostic

the SQHx. When no open circuit or short to ground condition exists, SQHx and SQLx are equal to

at ground potential. A short to ground is detected when SQLx voltage is at ground potential and the SQHx

Figure 18. Open Circuit and Short to Ground Diagnostic Diagram

The open circuit and short to ground conditions are summarized in the table below. A fault condition exists

Table 9. Open Circuit / Short to Ground Fault Condition

4.13 Resistance Measurement

In a resistance measurement test, OSD provides a current source, ISRC, on SQHx and a current sink,

ISINK, on SQLx. The 8-bit ADC is multiplexed between the deployment loops. This ADC converts the volt-

age across the SQHx and SQLx. The conversion results is stored for SPI retrieval. Figure 19 shows the

resistance measurement diagram.

Comparator Output

Condition

OC

SG

00

Invalid State

0

1

Short to Ground

1

0

Normal operation

1

1

Open Circuit

SB

th

Diagnostics

SQLx

SQHx

VRESx

Off

Off

I

PD

gnd0

GNDx

I

BIAS

V

BIAS

Diagnostics

SQLx

SQHx

VRESx

Off

Off

SG

th

OC

th

I

PD

gnd0

GNDx

I

BIAS

V

BIAS

Obsolete

Product(s)

- Obsolete

Product(s)