Datasheet

LTC2974
43
2974fc
For more information www.linear.com/LTC2974
MFR_EE_DATA Data Contents
BIT(S) SYMBOL OPERATION
b[7:0] Mfr_ee_data[7:0] To read user space
1) Use the appropriate Mfr_ee_unlock sequence to configure for Mfr_ee_data commands with or without PEC.
2) Read Mfr_ee_data[0] = PackingId (MFR Specific ID).
3) Read Mfr_ee_data[1] = NumberOfUserWords (total number of 16-bit word available).
4) Read Mfr_ee_data[2] through Mfr_ee_data[NumberOfWord+1] (User EEPROM data contents)
To write user space
1) Initialize the user memory using the sequence described for the MFR_EE_ERASE command.
2) Use the appropriate Mfr_ee_unlock sequence to configure for Mfr_ee_data commands with or without PEC.
3) Write Mfr_ee_data[0] through Mfr_ee_data[NumberOfWord-1] (User EEPROM data content to be wriiten)
The part will indicate it is busy erasing the EEPROM by the mechanism detailed below.
Response When Part Is Busy
The part will indicate it is busy accessing the EEPROM by the following mechanism:
1) Clearing Mfr_common_busyb of the MFR_COMMON register. This byte can always be read and will never NACK a
byte read request even if the part is busy.
2) NACKing commands other than MFR_COMMON.
MFR_EE Erase and Write Programming Time
The program time per word is typically 0.17ms and will require spacing the I
2
C/SMBus writes at greater than 0.17ms
to guarantee the write has completed. The Mfr_ee_erase command takes approximately 400ms. We recommend using
MFR_COMMON for handshaking.
pMbus coMManD DescripTion
VIN_ON, VIN_OFF, VIN_OV_FAULT_LIMIT, VIN_OV_WARN_LIMIT, VIN_UV_WARN_LIMIT and
VIN_UV_FAULT_LIMIT
These commands provide voltage supervising limits for the input voltage V
IN_SNS
.
INPUT VOLTAGE COMMANDS AND LIMITS
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED FORMAT UNITS EEPROM
DEFAULT
VALUE
REF
PAGE
VIN_ON 0x35 Input voltage (VIN_SNS) above which power
conversion can be enabled.
R/W Word N L11 V Y 10.0
0xD280
43
VIN_OFF 0x36 Input voltage (VIN_SNS) below which power
conversion is disab
led. A
ll VOUT_EN pins go
off immediately or sequence off after TOFF_
DELAY (See Mfr_config_track_enn).
R/W Word N L11 V Y 9.0
0xD240
43
VIN_OV_FAULT_LIMIT 0x55 Input overvoltage fault limit measured at
VIN_SNS pin.
R/W Word N L11 V Y 15.0
0xD3C0
43
VIN_OV_WARN_LIMIT 0x57 Input overvoltage warning limit measured at
VIN_SNS pin.
R/W Word N L11 V Y 14.0
0xD380
43
VIN_UV_WARN_LIMIT 0x58 Input undervoltage warning limit measured at
VIN_SNS pin.
R/W Word N L11 V Y 0
0x8000
43
VIN_UV_FAULT_LIMIT 0x59 Input undervoltage fault limit measured at
VIN_SNS pin.
R/W Word N L11 V Y 0
0x8000
43