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L9634

4.10 Short Between Loops Diagnostic

OSD has a loop bias voltage that is multiplexed between the eight deployment loops. The bias voltage is

pulled-up to VDIAG_BIAS. Each deployment loop is pulled to ground through a current sink, IPD. If one

of these loops is shorted to the one that is biased, a "Short Between Loops" fault bit is asserted and re-

ported via SPI. Refer to Figure 16 for Short Between Loops diagram.

Short between loops test is initiated when OSD receives one of the following message:

The test terminates when OSD receives one of the following message:

If the test is in progress, OSD will continue the test when any of the following messages is received:

Figure 16. Short Between Loops Diagram

After a POR event, short between loop is disabled. Need to receive a SPI command to execute a short

between loop diagnostic.

4.11 Short to Battery Diagnostic

During a short to battery test, a current source referenced to VDD is connected to the SQHx. When no

short to battery condition exists, SQHx and SQLx are equal to VDIAG_BIAS. If the voltage on SQHx is

above SBth for tFLT_DLY, OSD will assert the short to battery fault. Refer to Figure 17 for a short to battery

test diagram.

SQL0

SG

th

SB

th

SQH0

VRES0

SQL1-7

SG

th

SQH1-7

VRES1-7

Diagnostics

Off

Off

Off

Off

I

PD

I

BIAS

I

PD

gnd0

gnd0

GND0

GND1-7

V

BIAS

SB

th

Obsolete

Product(s)

- Obsolete

Product(s)