MAX34441EVKIT# Maxim Integrated, MAX34441EVKIT# Datasheet - Page 19

• Manufacturer Part Number: MAX34441EVKIT#
• Description: Power Management IC Development Tools MAX34441 Eval Kit
• Manufacturer: Maxim Integrated
• Type: PWM Controllersr
• Series: MAX34441r

Specifications of MAX34441EVKIT#

• Rohs: yes
• Product: Power Management Development Tools
• Tool Is For Evaluation Of: MAX34441
• Interface Type: I2C
• Maximum Operating Temperature: + 85 C
• Part # Aliases: 90-34441#K00

When a read request is issued to a write-only
command (CLEAR_FAULTS, STORE_DEFAULT_ALL,
RESTORE_DEFAULT_ALL), the device does the following:
1) ACKs the address byte.
2) Ignores the command.
3) Sends all ones (FFh) as long as the host keeps
4) Sets the CML bit in STATUS_BYTE.
5) Sets the CML bit in STATUS_WORD.
6) Sets the DATA_FAULT bit in STATUS_CML.
7) Notifies the host through ALERT assertion (if enabled).
When a write request is issued to a read-only command,
the device does the following:
1) Ignores the command.
2) Sets the CML bit in STATUS_BYTE.
3) Sets the CML bit in STATUS_WORD.
4) Sets the COMM_FAULT bit in STATUS_CML.
5) Notifies the host through ALERT assertion (if enabled).
If during an active SMBus communication sequence
the SCL signal is held low for greater than the timeout
duration (nominally 30ms), the device terminates the
sequence and resets the serial bus. It takes no other
action. No status bits are set.
From a software perspective, the device appears as a
PMBus device capable of executing a subset of PMBus
commands. A PMBus 1.1-compliant device uses the
SMBus version 1.1 for transport protocol and responds
to the SMBus slave address. In this data sheet, the term
SMBus is used to refer to the electrical characteristics
of the PMBus communication using the SMBus physi-
cal layer. The term PMBus is used to refer to the PMBus
command protocol. The device employs a number of
standard SMBus protocols such as Write Word, Read
Word, Write Byte, Read Byte, Send Byte, and so on to
program output voltage and warning/faults thresholds,
read monitored data, and provide access to all manufac-
turer-specific commands.
acknowledging.
Host Reads from a Write-Only Command
Host Writes to a Read-Only Command
PMBus 5-Channel Power-Supply Manager
PMBus Operation
SMBus Timeout
and Intelligent Fan Controller
The device supports the group command. The group
command is used to send commands to more than one
PMBus device. It is not required that all the devices
receive the same command. However, no more than
one command can be sent to any one device in one
group command packet. The group command must not
be used with commands that require receiving devices
to respond with data, such as the STATUS_BYTE com-
mand. When the device receives a command through
this protocol, it immediately begins execution of the
received command after detecting the STOP condition.
The device supports the PAGE command and uses it to
select which individual channel to access. When a data
word is transmitted, the lower order byte is sent first and
the higher order byte is sent last. Within any byte, the
most significant bit (MSB) is sent first and the least sig-
nificant bit (LSB) is sent last.
The device supports a subset of the commands defined
in the PMBus™ Power System Management Protocol
Specification Part II - Command Language, Revision 1.1.
For detailed specifications and the complete list of
PMBus commands, refer to Part II of the PMBus speci-
fication available at www.PMBus.org. The supported
PMBus commands and the corresponding device behav-
ior are described in this document. All data values are
represented in DIRECT format, unless otherwise stated.
Whenever the PMBus specification refers to the PMBus
device, it is referring to the MAX34441 operating in con-
junction with a power supply or fan. While the command
can call for turning on or turning off the PMBus device,
the MAX34441 always remains on to continue com-
municating with the PMBus master, and the MAX34441
transfers the command to the power supply accordingly.
Voltage data for commanding or reading the output
voltage or related parameters (such as the overvolt-
age threshold) is presented in DIRECT format. DIRECT
format data is a 2-byte, two’s complement binary value.
DIRECT format data can be used with any command that
sends or reads a parametric value. The DIRECT format
uses an equation and defined coefficients to calculate
the desired values. Table 3 shows the coefficients used
by the device.
PMBus Protocol Support
Data Format
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