L9669 データシートの表示（PDF） - STMicroelectronics

部品番号

コンポーネント説明

メーカー

L9669

FAULT TOLERANT CAN TRANSCEIVER

STMicroelectronics 

L9669

1.4 Diagnosis

A serial interface is available to retrieve diagnostic informations. Diagnostic data can be requested by using EN

as serial clock and evaluating NERR.

Figure 4.

NSTB

EN

Bus Error

detected

NERR

E1 E2

or E5 or E9

E3

E4

tDmax

No Bus Errors

Mode

(Example)

Normal

Diagnosis

RXonly

99AT0004

Delay between falling slope at EN and reaction at NERR: 0.7 µs...3.0 µs

(NERR is synchronized with internal clock).

Standby

Readout is initialized by a negative edge on EN and acknowledged by NERR entering HIGH state. Following

the next negative edge the first error status bit is displayed on NERR according to the data table below. If no

edge on EN is detected for a time longer than tDmax diagnosis is disabled and operation continuous in the mode

given by NSTB and EN with NERR showing bus errors or wake-up correspondingly. If the clock continues, the

readout sequence starts over again with the initial bit set HIGH.

The following errors are displayable (sequence listed in chronological order):

– error status bit 1 (LSB):

HIGH if Error 1 or 5

– error status bit 2:

HIGH if Error 2 or 9

– error status bit 3:

HIGH if Error 3

– error status bit 4:

HIGH if Error 4

– error status bit 5:

HIGH if Error 6

– error status bit 6:

HIGH if Error 8

– error status bit 7:

HIGH if Error 10

– error status bit 8:

HIGH if Thermal shutdown of Transceiver

1.5 Protections

A current limiting circuit protects the transmitter outputs against short-circuit to battery, ground and shorted

wires.

If the junction temperature exceeds a maximum value, the transmitter output stages are disabled.

10/13

Share Link: