Linear Technology Analog Devices LTC3882-1, Техническое описание

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LTC3882-1
29
Rev A
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OPERATION
Table 1. LTC3882-1 Fault Log Contents
RECORD TYPE
STARTING
BYTE
ENDING
BYTE COMMENTS
Header Information 0 26 See Table 2.
Fault Event Record 27 46 Fault may have occurred
anywhere during this event
record. See byte 4 of Table 2
and all of Table 3 and Table 4.
Event Record N-1 47 66 Last complete cyclical data
read before the fault was
detected.
Event Record N-2 67 86 Older data record.
Event Record N-3 87 106
Event Record N-4 107 126
Event Record N-5 127 146 Oldest recorded data.
Table 2. Fault Log Header Information
RECORD BITS FORMAT
BLOCK
BYTE
COUNT DETAILS
Fault Log Preface [7:0] ASC 0 Returns LTxx beginning at byte 0 if a partial or complete fault log exists. Word xx is
a factory identifier that may vary part to part.
[7:0] 1
[15:8] Reg 2
[7:0] 3
Fault Source [7:0] Reg 4 Refer to Table 3.
MFR_REAL_TIME [7:0] Reg 5 48 bit share-clock counter value when fault occurred (200µs resolution).
[15:8] 6
[23:16] 7
[31:24] 8
[39:32] 9
[47:40] 10
MFR_VOUT_PEAK (PAGE 0) [15:8] L16 11 Peak READ_VOUT on Channel 0 since last power-on or CLEAR_PEAKS command.
[7:0] 12
MFR_VOUT_PEAK (PAGE 1) [15:8] L16 13 Peak READ_VOUT on Channel 1 since last power-on or CLEAR_PEAKS command.
[7:0] 14
MFR_IOUT_PEAK (PAGE 0) [15:8] L11 15 Peak READ_IOUT on Channel 0 since last power-on or CLEAR_PEAKS command.
[7:0] 16
MFR_IOUT_PEAK (PAGE 1) [15:8] L11 17 Peak READ_IOUT on Channel 1 since last power-on or CLEAR_PEAKS command.
[7:0] 18
MFR_VIN_PEAK [15:8] L11 19 Peak READ_VIN since last power-on or CLEAR_PEAKS command.
[7:0] 20
READ_TEMPERATURE1 (PAGE 0) [15:8] L11 21 External temperature sensor 0 during last event.
[7:0] 22
READ_TEMPERATURE1 (PAGE 1) [15:8] L11 23 External temperature sensor 1 during last event.
[7:0] 24
READ_TEMPERATURE2 [15:8] L11 25 Internal temperature sensor during last event.
[7:0] 26
The MFR_FAULT_LOG command uses a block read protocol
with a fixed length of 147 bytes. The LTC3882-1 returns a
block byte count of zero if a fault log is not present.
Contents of a fault log are shown in Table 1 through Table
4. Refer to Table 6 for an explanation of data formats. Each
event record represents one complete conversion cycle
through all multiplexed monitor ADC inputs and related
status. The six most recent event records are maintained
in internal memory in reverse chronological order unless
the part is reset. Then the four most recent events are
maintained in EEPROM. When a fault log is created the
present ADC input cycle is completed and the ADC input
being converted at the time of the fault is noted in the log
header record.