Rainbow Electronics MAX34441 User Manual
19-5488; Rev 0; 8/10
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
General Description
The MAX34441 is a complex system monitor that can manage up to five power supplies and a fan. The power-supply
manager monitors the power-supply output voltage and
constantly checks for user-programmable overvoltage and
undervoltage thresholds. It can also margin the powersupply output voltage up or down to 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.
The device also contains closed-loop fan-speed control.
Based on user-programmable settings for fan-control
PWM duty cycles or RPM speeds at particular temperature breakpoints, the device automatically adjusts the fan
speed in a manner to reduce audible noise and power
consumption.
Applications
Network Switches/Routers
Base Stations
Servers
Smart Grid Network Systems
Industrial Controls
MAX34441
Features
S 5 Channels of Power-Supply Management
Voltage Measurement/Monitoring
Differential 12-Bit 1% Accurate ADC
Min/Max Threshold Excursion Detection
Supports Current Monitoring with External
Current-Sense Amplifier
Automatic Closed-Loop Margining
Programmable Up and Down Sequencing
Power-Good Output
S 1 Channel of Fan Control
Supports 3-Wire and 4-Wire Fans
Automatic Closed-Loop Fan-Speed Control
Support for Dual Tachometer Fans
Fan-Fault Detection
S Supports Up to Six Temperature Sensors
External Thermal Diode Interface with
Automatic Series Resistance Cancellation
One Internal Temperature Sensor
Support for Up to Four Additional I2C Digital
Temp Sensor ICs
Fault Detection on All Temp Sensors
S PMBus™-Compliant Command Interface
S I2C/SMBus™-Compatible Serial Bus with Bus
Timeout Function
S On-Board Nonvolatile Fault Logging and Default
Configuration Setting
S No External Clocking Required
S +3.3V Supply Voltage
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX34441ETL+
MAX34441ETL+T
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
PMBus is a trademark of SMIF, Inc.
SMBus is a trademark of Intel Corp.
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata.
_______________________________________________________________ Maxim Integrated Products 1
-40NC to +85NC
-40NC to +85NC
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
40 TQFN-EP*
40 TQFN-EP*
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
TABLE OF CONTENTS
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical Specifications: I2C/SMBus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
I2C/SMBus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
MAX34441
Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Multiple Device Connection Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Address Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
SMBus/PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
SMBus/PMBus Communication Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Group Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Group Command Write Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
ALERT and Alert Response Address (ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Alert Response Address (ARA) Byte Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Sends or Reads Too Few Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Sends or Reads Too Few Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Sends Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Reads Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Sends Improperly Set Read Bit in the Slave Address Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Unsupported Command Code Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Invalid Data Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Reads from a Write-Only Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Host Writes to a Read-Only Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
SMBus Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
PMBus Protocol Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Interpreting Received DIRECT Format Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Sending a DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Fault Management and Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
System Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Temperature Sensor Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
TABLE OF CONTENTS (continued)
Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Dual Fan Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Automatic Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Pulse Stretching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fan Spin-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
PMBus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
PAGE (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
OPERATION (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
ON_OFF_CONFIG (02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
CLEAR_FAULTS (03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
WRITE_PROTECT (10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
STORE_DEFAULT_ALL (11h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
RESTORE_DEFAULT_ALL (12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
CAPABILITY (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
VOUT_MODE (20h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
VOUT_MARGIN_HIGH (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
VOUT_MARGIN_LOW (26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
VOUT_SCALE_MONITOR (2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
IOUT_CAL_GAIN (38h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
FAN_CONFIG_1_2 (3Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
FAN_COMMAND_1 (3Bh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
VOUT_OV_FAULT_LIMIT (40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
VOUT_OV_WARN_LIMIT (42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
VOUT_UV_WARN_LIMIT (43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
VOUT_UV_FAULT_LIMIT (44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
IOUT_OC_WARN_LIMIT (46h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
IOUT_OC_FAULT_LIMIT (4Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
OT_FAULT_LIMIT (4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
OT_WARN_LIMIT (51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
POWER_GOOD_ON (5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
POWER_GOOD_OFF (5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
TON_DELAY (60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
TON_MAX_FAULT_LIMIT (62h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
TOFF_DELAY (64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
STATUS_BYTE (78h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
STATUS_WORD (79h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
STATUS_VOUT (7Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
STATUS_CML (7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MAX34441
3
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
TABLE OF CONTENTS (continued)
STATUS_MFR_SPECIFIC (80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
STATUS_FANS_1_2 (81h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
READ_VOUT (8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
READ_IOUT (8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
READ_TEMPERATURE_1 (8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
READ_FAN_SPEED_1 (90h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MAX34441
PMBUS_REVISION (98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MFR_ID (99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MFR_MODEL (9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MFR_REVISION (9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MFR_LOCATION (9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
MFR_DATE (9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
MFR_SERIAL (9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
MFR_MODE (D1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
MFR_VOUT_PEAK (D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
MFR_IOUT_PEAK (D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_TEMPERATURE_PEAK (D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_VOUT_MIN (D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_FAULT_RESPONSE (D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_FAULT_RETRY (DAh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MFR_NV_FAULT_LOG (DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MFR_TIME_COUNT (DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
MFR_MARGIN_CONFIG (E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
MFR_TEMP_SENSOR_CONFIG (F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
MFR_FAN_CONFIG (F1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
MFR_FAN_LUT (F2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
TEMPERATURE STEP: Temperature Level Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
FAN SPEED STEP: Fan PWM Duty Cycle or Fan Speed Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
MFR_READ_FAN_PWM (F3h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
MFR_FAN_FAULT_LIMIT (F5h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
MFR_FAN_WARN_LIMIT (F6h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Applications Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Power-Supply Decoupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Open-Drain Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Package Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
LIST OF FIGURES
Figure 1. Automatic Fan Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 2. Fan Speed Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 3. Fan Spin-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 4. Power-Supply Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 5. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 6. Fan Lookup Table (LUT) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
LIST OF TABLES
Table 1. PMBus Command Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 2. PMBus/SMBus Serial-Port Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3. PMBus Command Code Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 4. Coefficients for DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 5. Device Parametric Monitoring States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 6. DS75LV Address Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 7. Fan Control Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 8. Page Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 10. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 11. ON_OFF_CONFIG (02h) Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 12. WRITE_PROTECT Command Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 13. CAPABILITY Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 14. VOUT_SCALE_MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 15. FAN_CONFIG_1_2 Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 16. PWM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 17. RPM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 18. IOUT_OC_FAULT_LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 19. TON_MAX_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 20. STATUS_BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 21. STATUS_WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 22. STATUS_VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 23. STATUS_CML. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 24. STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 25. STATUS_FANS_1_2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 26. MFR_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 27. MFR_FAULT_RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 28. MFR_FAULT_RESPONSE Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Table 29. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 30. MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 31. MFR_TEMP_SENSOR_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 32. MFR_FAN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 33. MFR_FAN_LUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 34. Valid Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 35. Monitored Fan Fault and Warning Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
MAX34441
5
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
ABSOLUTE MAXIMUM RATINGS
VDD to VSS ...........................................................-0.3V to +5.5V
RS- to VSS ............................................................-0.3V to +0.3V
All Other Pins Except REG18 and
REG25 Relative to VSS ........................ -0.3V to (VDD + 0.3V)*
Continuous Power Dissipation (TA = +70NC)
40-Pin TQFN
(derate 35.7mW/NC above +70NC) .........................2857.1mW
*Subject to not exceeding +5.5V.
MAX34441
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
(TA = -40NC to +85NC.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
VDD Operating Voltage Range V
Input Logic 1 V
Input Logic 0 V
Input Logic-High: SCL, SDA,
MSCL, MSDA
Input Logic-Low: SCL, SDA,
MSCL, MSDA
V
I2C_IH
V
I2C_IL
DD
(Note 1) 2.7 5.5 V
IH
IL
2.7V P VDD P 3.6V (Note 1)
2.7V P VDD P 3.6V (Note 1)
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range ............................ -55NC to +125NC
Lead Temperature (soldering, 10s) ................................+260NC
Soldering Temperature (reflow) ......................................+260NC
0.7 x
V
DD
-0.3
2.1
-0.3 +0.8 V
VDD +
0.3
0.3 x
V
DD
VDD +
0.3
V
V
V
DC ELECTRICAL CHARACTERISTICS
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
I
Supply Current
Brownout Voltage V
Brownout Hysteresis V
Internal System Clock f
System Clock Error (Note 3) f
Output Logic-Low V
Output Logic-High V
PWM, PSEN Pullup Current I
ADC Internal Reference 1.225 V
ADC Voltage Measurement Error V
ADC Internal Reference
Temperature Drift
6
CPU
I
PROGRAM
BO
BOH
MOSC
ERR:MOSC
OL1
OH1
PU
ERR
(Note 2) 2.5
8
Monitors VDD (Note 1) 2.40 2.46 2.55 V
Monitors VDD (Note 1) 30 mV
4.0 MHz
+25NC P TA P +85NC
-40NC P TA P +25NC
IOL = 4mA (Note 1) 0.4 V
IOH = -2mA (Note 1)
V
= VSS, VDD = 3.3V 38 55 107
PIN
-3 +2
-6.5 +1.6
VDD -
0.5
-1 +1 %
-0.5 +0.5 %
mA
%
V
FA
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
DC ELECTRICAL CHARACTERISTICS (continued)
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ADC Internal Reference Initial
Accuracy (+25NC)
ADC Full-Scale Input Voltage V
ADC Measurement Resolution V
ADC Bit Resolution 12 Bits
RS+ Input Resistance R
ADC Integral Nonlinearity INL
ADC Differential Nonlinearity DNL
ADC Offset V
Internal Temperature
Measurement Error
Remote Temperature
Measurement Error
(MAX34441 Error Only)
Store Default All Time 37 ms
Nonvolatile Log Write Time 12 ms
Nonvolatile Log Delete Time 200 ms
Flash Endurance N
Data Retention
Voltage Sample Rate 5 ms
Current Sample Rate 200 ms
RPM Sample Rate 1000 ms
Temperature Sample Rate 1000 ms
Device Startup Time
PWM Frequency
PWM Resolution
FS
LSB
IN
OFFSET
FLASH
TA = -40NC to +85NC
TA = 0NC to +60NC,
T
= +60NC to +120NC
DIODE
TA = 0NC to +60NC,
T
= -45NC to +120NC
DIODE
TA = -40NC to +85NC,
T
= +60NC to +120NC
DIODE
TA = -40NC to +85NC,
T
= -45NC to +120NC
DIODE
TA = +50NC
TA = +50NC
Measured from POR until monitoring
begins
Power supply 62.5 kHz
Fan 30 25,000 Hz
Power supply 6
Fan 7
-1 +1 mV
1.213 1.225 1.237 V
300
15
Q4
Q1
Q2
-3 +3
-1.5 +1.5
-1.75 +1.75
-2.75 +2.75
-3.0 +3.0
20,000
100 Years
12 ms
Write
Cycles
FV
MI
LSB
LSB
LSB
NC
NC
Bits
MAX34441
7
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
I2C/SMBus INTERFACE ELECTRICAL SPECIFICATIONS
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SCL Clock Frequency f
Bus Free Time Between STOP
and START Conditions
Hold Time (Repeated) START
Condition
MAX34441
Low Period of SCL t
High Period of SCL t
Data Hold Time t
Data Setup Time t
START Setup Time t
SDA and SCL Rise Time t
SDA and SCL Fall Time t
STOP Setup Time t
Clock Low Timeout t
SCL
t
BUF
t
HD:STA
LOW
HIGH
HD:DAT
SU:DAT
SU:STA
R
F
SU:STO
TO
Receive 0
Transmit 300
Note 1: All voltages are referenced to ground (VSS). Currents entering the IC are specified as positive, and currents exiting the IC
are negative.
Note 2: This does not include pin input/output currents.
Note 3: Guaranteed by design.
10 100 kHz
4.7
4.0
4.7
4.0
100 ns
4.7
300 ns
300 ns
4.0
25 35 ms
Fs
Fs
Fs
Fs
ns
Fs
Fs
I2C/SMBus Timing
SDA
t
BUF
t
LOW
SCL
t
HD:STA
STOP START REPEATED
NOTE: TIMING IS REFERENCED TO V
IL(MAX)
AND V
t
R
IH(MIN)
t
HD:DAT
.
8
t
HIGH
t
F
t
SU:DAT
START
t
SU:STA
t
HD:STA
t
SP
t
SU:STO
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Typical Operating Characteristics
(T
= +25°C, unless otherwise noted.)
A
MAX34441
SUPPLY CURRENT vs. TEMPERATURE
2.7
2.6
2.5
2.4
(mA)
DD
I
2.3
2.2
2.1
2.0
-40 100
VDD = 3.3V
TEMPERATURE (°C)
WEAK PULLUP VOLTAGE vs. TIME AT POR
(UNLOADED PINS, V
0V
0V
1V/div
= 3.3V)
DD
C1 = PSEN0
C3 = PWM0
C2 = V
MAX34441 toc03
DD
SUPPLY CURRENT vs. SUPPLY VOLTAGE
2.7
MAX34441 toc01
806040200-20
2.6
2.5
2.4
(mA)
DD
I
2.3
2.2
2.1
2.0
2.7 5.5
TA = +25°C
VDD (V)
MAX34441 toc02
5.14.74.33.93.53.1
IDD vs. TIME DURING A FLASH WRITE
= +25°C, VDD = 3.3V)
(T
A
1mA/div
MAX34441 toc04
0V
1ms/div
0A
2ms/div
FILTERED MARGINING VOLTAGE
vs. TIME DURING MARGIN UP
200mV/div
0V
100ms/div
MAX34441 toc05
9
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Pin Configuration
PSEN3
RS+1
REG18
21
DD
V
SS
V
RS-1
20
PWM3
19
PSEN4
18
PWM4
17
TACH5
16
PWM5
MSCL
15
14
MSDA
RST
13
12
RS-2
11
RS+2
MAX34441
TOP VIEW
SDA
SCL
A0/MUXSEL
FAULT
CONTROL
V
A1/PG/TACHSEL
ALERT
RS-5
RS+5
REG25
PSEN0
31
32
33
34
35
36
SS
37
38
39
40
+
1 2 4 5 6 7
SS
V
RS-4
PWM1
PSEN1
MAX34441
RS-3
RS+3
PSEN2
25
RS+0
PWM0
27282930 26 24 23 22
3
RS+4
PWM2
EP
8 9 10
RS-0
TQFN
(6mm × 6mm × 0.75mm)
Pin Description
PIN NAME FUNCTION
1 RS-4 Ground Reference for ADC4 Voltage Measurement
2, 21, 36 V
SS
3 RS+4 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-4
4 RS-3 Ground Reference for ADC3 Voltage Measurement
5 RS+3 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-3
6 RS+0 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-0
7 RS-0 Ground Reference for ADC0 Voltage Measurement
8 RS+1 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-1
9 V
DD
10 RS-1 Ground Reference for ADC1 Voltage Measurement
11 RS+2 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-2
12 RS-2 Ground Reference for ADC2 Voltage Measurement
13
RST
14 MSDA Master I2C Data Input/Output. Open-drain output.
15 MSCL Master I2C Clock Output. Open-drain output.
16 PWM5
17 TACH5 Fan Tachometer Input
18 PWM4
19 PSEN4
Digital-Supply Return Node (Ground)
Supply Voltage. Bypass VDD to VSS with a 0.1FF capacitor.
Reset Active-Low Input
Fan PWM Output #5. CMOS push-pull output. Low when the fan is disabled. A 100% duty cycle
implies this pin is continuously high.
PWM Margin Output #4. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
Power-Supply Enable Output #4. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
10
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Pin Description (continued)
PIN NAME FUNCTION
20 PWM3
22 REG18
23 PSEN3
24 PWM2
25 PSEN2
26 PWM1
27 PSEN1
28 PWM0
29 REG25
30 PSEN0
31 SDA I2C/SMBus-Compatible Input/Output
32 SCL I2C/SMBus-Compatible Clock Input
33 A0/MUXSEL
34
35 CONTROL
37
38
39 RS-5 Thermal Diode ADC Voltage Negative-Sense Input, Measurement Relative to RS+5
40 RS+5 Thermal Diode ADC Voltage Positive-Sense Input, Measurement Relative to RS-5
— EP Exposed Pad (Bottom Side of Package). Connect EP to VSS.
Note: All pins except VDD, VSS, REG18, REG25, ADC, and the EP are high impedance with a 50µA pullup during device power-up
and reset. After device reset, the weak pullup is removed, and the pin is configured as input or output.
FAULT
A1/PG/
TACHSEL
ALERT
PWM Margin Output #3. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
Regulator for Low-Voltage Digital Circuitry. Bypass REG18 to VSS with 1FF and 10nF capacitors. Do
not connect other circuitry to this pin.
Power-Supply Enable Output #3. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
PWM Margin Output #2. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
Power-Supply Enable Output #2. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
PWM Margin Output #1. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
Power-Supply Enable Output #1. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
PWM Margin Output #0. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
Regulator for Analog Circuitry. Bypass REG25 to VSS with 1FF and 10nF capacitors. Do not connect
other circuitry to this pin.
Power-Supply Enable Output #0. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
SMBus Address 0 Input/Multiplexer Control Output. This dual-function pin is sampled on device
power-up to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or
VDD to set the address. After device power-up, this pin becomes an output that acts as voltage/
current selector for an external analog multiplexer. MUXSEL is low for voltage measurements and
high for current measurements.
Active-Low, Open-Drain Fault Input/Output. This pin is asserted when one or more of the power supplies
in a global group are shut down due to a fault condition. Also, this pin is monitored and, when it is
asserted, all power supplies in a global group are shut down. This pin is used to provide hardware
control for power supplies in a global group across multiple devices. This output is unconditionally
deasserted when RST is asserted or the device is power cycled. This pin has a 50Fs deglitch filter.
Device Enable. Option through ON_OFF_CONFIG for active-low or active-high power-supply control.
This pin has a 50Fs deglitch filter.
SMBus Address 1 Input/Power-Good Output. This triple-function pin is sampled on device powerup to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or VDD to
set the address. After device power-up, this pin becomes an output that transitions high when all
the enabled power supplies are above their associated POWER_GOOD_ON thresholds. Alternately,
this pin can be programmed through MFR_MODE to select between two tachometers in dual-fan
applications.
Active-Low, Open-Drain Alert Output
MAX34441
11
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Block Diagram
MAX34441
V
V
REG25
V
REG18
V
MSDA
MSCL
SDA
SCL
RST
ALERT
FAULT
CONTROL
A0/MUXSEL
A1/PG/TACHSEL
DD
SS
SS
SS
POWER
CONTROL
2.5V
VREG
1.8V
VREG
4MHz
OSCILLATOR
SMBus
MASTER
INTERFACE
SMBus
SLAVE
INTERFACE
SYSTEM
CONTROL
SIGNALS
MAX34441
16-BIT
MAXQ
RISC CORE
PULSE-
WIDTH
MODULATOR
POWERSUPPLY
OUTPUT
ENABLES
FAN
TACHOMETER
INPUT
ADC
MUX
FLASHRAM
TEMP
SENSOR
PWM0
PWM1
PWM2
PWM3
PWM4
PWM5
PSEN0
PSEN1
PSEN2
PSEN3
PSEN4
TACH5
RS+0
RS-0
RS+1
RS-1
RS+2
RS-2
RS+3
RS-3
RS+4
RS-4
RS+5
RS-5
12
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Multiple Device Connection Diagram
+3.3V
ALERT
HOST
INTERFACE
CLOCK
DATA
CONTROL
RST
SDA
SCL
RST
ALERT
FAULT
CONTROL
A1/PG/TACHSEL
A0/MUXSEL
MAX34441
#0
MAX34441
ADDITIONAL DEVICES
+3.3V
SDA
SCL
RST
ALERT
FAULT
CONTROL
A1/PG/TACHSEL
A0/MUXSEL
MAX34441
#1
13
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, MAXQM 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-
MAX34441
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 powerdown. With the addition of an external current-sense
Thermal monitoring can be accomplished using up to six
temperature sensors, including an on-chip thermal sensor, four DS75LV digital thermometers, and a remote thermal diode. Temperature offset can be added to individual
sensors to compensate for thermal differences in a system. 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 particular 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 PMBuscompatible communications port. Address input connections are also provided to allow up to four MAX34441
devices to reside on the system’s I/O bus.
amplifier, the device can also monitor currents.
Table 1. PMBus Command Codes
PAGE
CODE COMMAND NAME TYPE
00h PAGE R/W Byte R/W R/W R/W R/W 1 N 00h
01h OPERATION R/W Byte R/W — — W 1 N 00h
02h ON_OFF_CONFIG R/W Byte R/W R/W R/W R/W 1 Y 1Ah
03h CLEAR_FAULTS Send Byte W W W W 0 N —
10h WRITE_PROTECT R/W Byte R/W R/W R/W R/W 1 N 00h
11h STORE_DEFAULT_ALL Send Byte W W W W 0 N —
12h RESTORE_DEFAULT_ALL Send Byte W W W W 0 N —
19h CAPABILITY Read Byte R R R R 1 N 00h/10h
20h VOUT_MODE Read Byte R R R R 1 FIXED 40h
25h VOUT_MARGIN_HIGH R/W Word R/W — — — 2 Y 0000h
26h VOUT_MARGIN_LOW R/W Word R/W — — — 2 Y 0000h
2Ah VOUT_SCALE_MONITOR R/W Word R/W — — — 2 Y 7FFFh
38h IOUT_CAL_GAIN R/W Word R/W — — — 2 Y 0000h
3Ah FAN_CONFIG_1_2 R/W Byte — R/W — — 1 Y 00h
3Bh FAN_COMMAND_1 R/W Word — R/W — — 2 Y FFFFh
40h VOUT_OV_FAULT_LIMIT R/W Word R/W — — — 2 Y 7FFFh
42h VOUT_OV_WARN_LIMIT R/W Word R/W — — — 2 Y 7FFFh
43h VOUT_UV_WARN_LIMIT R/W Word R/W — — — 2 Y 0000h
44h VOUT_UV_FAULT_LIMIT R/W Word R/W — — — 2 Y 0000h
46h IOUT_OC_WARN_LIMIT R/W Word R/W — — — 2 Y 7FFFh
4Ah IOUT_OC_FAULT_LIMIT R/W Word R/W — — — 2 Y 0000h
4Fh OT_FAULT_LIMIT R/W Word — — R/W — 2 Y 7FFFh
0–4
PAGE5PAGE
6–11
(NOTE 1)
PAGE
255
NO. OF
BYTES
FLASH
STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
MAXQ is a registered trademark of Maxim Integrated
Products, Inc.
14
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Table 1. PMBus Command Codes (continued)
PAGE
CODE COMMAND NAME TYPE
51h OT_WARN_LIMIT R/W Word — — R/W — 2 Y 7FFFh
5Eh POWER_GOOD_ON R/W Word R/W — — — 2 Y 0000h
5Fh POWER_GOOD_OFF R/W Word R/W — — — 2 Y 0000h
60h TON_DELAY R/W Word R/W — — — 2 Y 0000h
62h TON_MAX_FAULT_LIMIT R/W Word R/W — — — 2 Y 0000h
64h TOFF_DELAY R/W Word R/W — — — 2 Y 0000h
78h STATUS_BYTE Read Byte R R R R 1 N 00h
79h STATUS_WORD Read Word R R R R 2 N 0000h
7Ah STATUS_VOUT Read Byte R — — — 1 N 00h
7Eh STATUS_CML Read Byte R R R R 1 N 00h
80h STATUS_MFR_SPECIFIC Read Byte R — R — 1 N 00h
81h STATUS_FANS_1_2 Read Byte — R — — 1 N 00h
8Bh READ_VOUT Read Word R — — — 2 N 0000h
8Ch READ_IOUT Read Word R — — — 2 N 0000h
8Dh READ_TEMPERATURE_1 Read Word — — R — 2 N 0000h
90h READ_FAN_SPEED_1 Read Word — R — — 2 N 0000h
98h PMBUS_REVISION Read Byte R R R R 1 FIXED 11h
99h MFR_ID Read Byte R R R R 1 FIXED 4Dh
9Ah MFR_MODEL Read Byte R R R R 1 FIXED 52h
9Bh MFR_REVISION Read Word R R R R 2 FIXED 3030h
9Ch MFR_LOCATION Block R/W R/W R/W R/W R/W 8 Y (Note 3)
9Dh MFR_DATE Block R/W R/W R/W R/W R/W 8 Y (Note 3)
9Eh MFR_SERIAL Block R/W R/W R/W R/W R/W 8 Y (Note 3)
D1h MFR_MODE R/W Word R/W R/W R/W R/W 2 Y 0000h
D4h MFR_VOUT_PEAK R/W Word R/W — — — 2 N 0000h
D5h MFR_IOUT_PEAK R/W Word R/W — — — 2 N 0000h
D6h MFR_TEMPERATURE_PEAK R/W Word — — R/W — 2 N 8000h
D7h MFR_VOUT_MIN R/W Word R/W — — — 2 N 7FFFh
D9h MFR_FAULT_RESPONSE R/W Word R/W — — — 2 Y 0000h
DAh MFR_FAULT_RETRY R/W Word R/W R/W R/W R/W 2 Y 0000h
DCh MFR_NV_FAULT_LOG Block Read R R R R 255 Y (Note 4)
DDh MFR_TIME_COUNT Block Read R R R R 4 N (Note 5)
E0h MFR_MARGIN_CONFIG R/W Word R/W — — — 2 Y 0000h
F0h MFR_TEMP_SENSOR_CONFIG R/W Word — — R/W — 2 Y 0000h
F1h MFR_FAN_CONFIG R/W Word — R/W — — 2 Y 0000h
F2h MFR_FAN_LUT Block R/W — R/W — — 32 Y (Note 6)
F3h MFR_READ_FAN_PWM Read Word — R — — 2 N 0000h
F5h MFR_FAN_FAULT_LIMIT R/W Word — R/W — — 2 Y 0000h
F6h MFR_FAN_WARN_LIMIT R/W Word — R/W — — 2 Y 0000h
Note 1: Common commands are shaded. Access through any page results in the same device response.
Note 2: In the Flash Stored column, an “N” indicates that this parameter is not stored in flash memory when the STORE_
DEFAULT_ALL command is executed and the value shown in the Default Value column is automatically loaded upon
power-on reset or when the RST pin is asserted. A “Y” in the Flash Stored column indicates that the currently loaded value
in this parameter is stored in flash memory when the STORE_DEFAULT_ALL command is executed and is automatically
0–4
PAGE5PAGE
6–11
(NOTE 1)
PAGE
255
NO. OF
BYTES
FLASH
STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
MAX34441
15
PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
Table 1. PMBus Command Codes (continued)
loaded upon power-on reset or when the RST pin is asserted and the value shown in the Default Value column is the
value when shipped from the factory. “FIXED” in the Flash Stored column means this value is fixed at the factory and
cannot be changed.
Note 3: The factory-set default value for this 8-byte block is 3130313031303130h.
Note 4: The factory-set default value for the complete block of the MFR_NV_FAULT_LOG is FFh.
Note 5: The power-on reset value for this 4-byte block is 00000000h.
Note 6: The factory-set default value for the complete block of the MFR_FAN_LUT is 00h.
MAX34441
Table 2. PMBus/SMBus Serial-Port
Address
A1 A0
100kI to V
100kI to V
SS
DD
100kI to V
100kI to V
100kI to V
100kI to V
READ WORD FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 8 1 1
SLAVE
S
ADDRESS
W A
READ BYTE FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 1
SLAVE
S
ADDRESS
W A
SS
DD
SS
DD
COMMAND
CODE
COMMAND
CODE
7-BIT SLAVE
ADDRESS
1101 010 (D4h)
1101 011 (D6h)
1101 100 (D8h)
1101 101 (DAh)
A Sr
A Sr
Address Select
On device power-up, the device samples the A0 and A1
pins to determine the PMBus/SMBus serial-port address.
SMBus/PMBus Operation
The device implements the PMBus command structure
using the SMBus format. The structure of the data flow
between the host and the slave is shown below for several different types of transactions. All transactions begin
with a host sending a command code that is immediately
preceded with a 7-bit slave address (R/W = 0). Data is
sent most significant bit (MSB) first.
SMBus/PMBus Communication Examples
SLAVE
ADDRESS
SLAVE
ADDRESS
R A
R A DATA BYTE NA P
DATA BYTE
LOW
A
DATA BYTE
HIGH
NA P
WRITE WORD FORMAT
1 7 1 1 8 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
DATA BYTE
A
LOW
A
DATA BYTE
HIGH
WRITE BYTE FORMAT
1 7 1 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A DATA BYTE A P
SEND BYTE FORMAT
1 7 1 1 8 1 1
16
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A P
A P
KEY:
S = START
Sr = REPEATED START
P = STOP
W = WRITE BIT (0)
R = READ BIT (1)
A = ACKNOWLEDGE (0)
NA = NOT ACKNOWLEDGE (1)
SHADED BLOCK = SLAVE TRANSACTION
Loading...