MAX34441 Datasheet, PDF (14/53 Pages) Maxim Integrated Products – PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller

PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Detailed Description
The MAX34441 is a highly integrated system monitor
based upon a 4MHz, 16-bit, MAXQ^M microcontroller with
factory-programmed functionality to monitor up to five
power supplies and a system cooling fan. The device
provides power-supply closed-loop control, fan-speed
monitoring, and local/remote thermal-sensing facilities.
The power-supply manager monitors the power-supply
output voltage and constantly checks for user-pro-
grammable overvoltage and undervoltage thresholds. It
also can margin the power-supply output voltage up or
down by a user-programmable level. The margining is
performed in a closed-loop arrangement, whereby the
device automatically adjusts a pulse-width-modulated
(PWM) output and then measures the resultant output
voltage. The power-supply manager can also sequence
the supplies in any order at both power-up and power-
down. With the addition of an external current-sense
amplifier, the device can also monitor currents.
Thermal monitoring can be accomplished using up to six
temperature sensors, including an on-chip thermal sen-
sor, four DS75LV digital thermometers, and a remote ther-
mal diode. Temperature offset can be added to individual
sensors to compensate for thermal differences in a sys-
tem. Communication with the DS75LV temperature sensor
is conducted through a dedicated I²C/SMBus interface.
The device also contains closed-loop fan-speed control.
Based on user-programmable settings for fan-control
PWM duty cycles or for fan RPM speeds at particu-
lar temperature breakpoints, the device automatically
adjusts the fan speed in a manner to reduce audible
noise and power consumption.
The device provides ALERT and FAULT output signals.
Host communications are conducted through a PMBus-
compatible communications port. Address input con-
nections are also provided to allow up to four MAX34441
devices to reside on the system’s I/O bus.
Table 1. PMBus Command Codes
CODE
COMMAND NAME
00h PAGE
01h OPERATION
02h ON_OFF_CONFIG
03h CLEAR_FAULTS
10h WRITE_PROTECT
11h STORE_DEFAULT_ALL
12h RESTORE_DEFAULT_ALL
19h CAPABILITY
20h VOUT_MODE
25h VOUT_MARGIN_HIGH
26h VOUT_MARGIN_LOW
2Ah VOUT_SCALE_MONITOR
38h IOUT_CAL_GAIN
3Ah FAN_CONFIG_1_2
3Bh FAN_COMMAND_1
40h VOUT_OV_FAULT_LIMIT
42h VOUT_OV_WARN_LIMIT
43h VOUT_UV_WARN_LIMIT
44h VOUT_UV_FAULT_LIMIT
46h IOUT_OC_WARN_LIMIT
4Ah IOUT_OC_FAULT_LIMIT
4Fh OT_FAULT_LIMIT
TYPE
R/W Byte
R/W Byte
R/W Byte
Send Byte
R/W Byte
Send Byte
Send Byte
Read Byte
Read Byte
R/W Word
R/W Word
R/W Word
R/W Word
R/W Byte
R/W Word
R/W Word
R/W Word
R/W Word
R/W Word
R/W Word
R/W Word
R/W Word
PAGE
0–4
R/W
R/W
R/W
W
R/W
W
W
R
R
R/W
R/W
R/W
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
—
PAGE PAGE
5
6–11
(NOTE 1)
R/W R/W
—
—
R/W R/W
W
W
R/W R/W
W
W
W
W
R
R
R
R
—
—
—
—
—
—
—
—
R/W
—
R/W
—
—
—
—
—
—
—
—
—
—
—
—
—
—
R/W
PAGE
255
R/W
W
R/W
W
R/W
W
W
R
R
—
—
—
—
—
—
—
—
—
—
—
—
—
NO. OF
BYTES
1
1
1
0
1
0
0
1
1
2
2
2
2
1
2
2
2
2
2
2
2
2
FLASH
STORED
(NOTE 2)
N
N
Y
N
N
N
N
N
FIXED
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
DEFAULT
VALUE
(NOTE 2)
00h
00h
1Ah
—
00h
—
—
00h/10h
40h
0000h
0000h
7FFFh
0000h
00h
FFFFh
7FFFh
7FFFh
0000h
0000h
7FFFh
0000h
7FFFh
MAXQ is a registered trademark of Maxim Integrated
Products, Inc.
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