PET1600-12-074NA Datasheet, PDF (18/25 Pages) Bel Fuse Inc. – AC input with power factor correction

PET1600-12-074NA
Figure 29 – SMBALERT_L connection
PSU 1 PDU
SMB-
3.3V
≥1kΩ
ALERT_L
PSU 2
SMB-
ALERT_L
The controller and the EEPROM in the power supply share the same I²C bus physical layer (see Figure 30) and can be
accessed under different addresses, see ADDRESS SELECTION.
The SDA/SCL lines are connected directly to the controller and EEPROM which are supplied by internal 3.3V.
The EEPROM provides 256 bytes of user memory. None of the bytes are used for the operation of the power supply.
Figure 30 - I²C Bus to DSP and EEPROM
A2..0
Address Selection
SDA
DSP
SCL
Protection
EEPROM
The EEPROM follows the industry communication protocols used for this type of device. Even though page write / read
commands are defined, it is recommended to use the single byte write / read commands.
WRITE
The write command follows the SMBus 1.1 Write Byte protocol. After the device address with the write bit cleared a first
byte with the data address to write to is sent followed by the data byte and the STOP condition. A new START condition
on the bus should only occur after 5ms of the last STOP condition to allow the EEPROM to write the data into its
memory.
S Address W A Data Address A
Data
AP
READ
The read command follows the SMBus 1.1 Read Byte protocol. After the device address with the write bit cleared the
data address byte is sent followed by a repeated start, the device address and the read bit set. The EEPROM will
respond with the data byte at the specified location.
866.513.2839
[e-mail]
© 2015 Bel Power Solutions, Inc.
BCD.00350_AC