Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsDev KitsPCB design board

_______________________________________________________________ Maxim Integrated Products 1

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.

PMBus 5-Channel Power-Supply Manager

and Intelligent Fan Controller

MAX34441

19-5488; Rev 1; 1/12

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

*EP = Exposed pad.

Ordering Information

General Description

The MAX34441 is a complex system monitor that can man-

age 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 power-

supply output voltage up or down to a user-programma-

ble level. The margining is performed in a closed-loop

arrangement whereby the device automatically adjusts

a pulse-width-modulated (PWM) output and then mea-

sures 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 tempera-

ture 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

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 I

C Digital

Temp Sensor ICs

Fault Detection on All Temp Sensors

S PMBus™-Compliant Command Interface

S I

C/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

PMBus is a trademark of SMIF, Inc.

PART TEMP RANGE PIN-PACKAGE

MAX34441ETL+

-40NC to +85NC

40 TQFN-EP*

MAX34441ETL+T

-40NC to +85NC

40 TQFN-EP*

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.

Summary of content (53 pages)

PAGE 1
9-5488; Rev 1; 1/12 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 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.
PAGE 2
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TABLE OF CONTENTS Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 3
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Dual Fan Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Automatic Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 4
MAX34441 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) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 5
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Figure Figure Figure Figure Figure Figure 1. Automatic Fan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Fan Speed Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Fan Spin-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 6
MAX34441 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) TQFN (derate 35.7mW/NC above +70NC)...............2857.1mW Operating Temperature Range.......
PAGE 7
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller (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 ADC Internal Reference Initial Accuracy (+25NC) TYP -1 ADC Full-Scale Input Voltage VFS ADC Measurement Resolution VLSB 1.213 1.225 MAX UNITS +1 mV 1.
PAGE 8
MAX34441 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 100 kHz SCL Clock Frequency fSCL 10 Bus Free Time Between STOP and START Conditions tBUF 4.7 Fs Hold Time (Repeated) START Condition tHD:STA 4.0 Fs Low Period of SCL tLOW 4.
PAGE 9
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE 2.6 2.6 2.5 2.4 IDD (mA) 2.5 IDD (mA) MAX34441 toc02 2.7 MAX34441 toc01 2.7 VDD = 3.3V 2.3 2.4 TA = +25°C 2.3 2.2 2.2 2.1 2.1 2.0 2.0 -40 -20 0 20 40 60 80 2.7 100 3.1 3.5 3.9 4.3 4.7 5.1 5.5 TEMPERATURE (°C) VDD (V) WEAK PULLUP VOLTAGE vs. TIME AT POR (UNLOADED PINS, VDD = 3.3V) IDD vs.
PAGE 10
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VSS REG18 PSEN3 PWM2 PWM1 PSEN2 PSEN1 PWM0 TOP VIEW REG25 PSEN0 MAX34441 Pin Configuration 30 29 28 27 26 25 24 23 22 21 SDA 31 20 PWM3 SCL 32 19 PSEN4 A0/MUXSEL 33 18 PWM4 FAULT 34 17 TACH5 CONTROL 35 16 PWM5 MAX34441 VSS 36 15 MSCL A1/PG/TACHSEL 37 14 MSDA ALERT 38 RS-5 39 13 RST EP + 12 RS-2 11 RS+2 7 8 9 10 VDD RS-1 6 RS-0 RS+4 5 RS+1 VSS 4 RS+0 3 RS-3 2 RS+3 1 RS-4 RS+5 40 TQFN (6mm ×
PAGE 11
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller PIN NAME FUNCTION 20 PWM3 PWM Margin Output #3. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 22 REG18 Regulator for Low-Voltage Digital Circuitry. Bypass REG18 to VSS with 1FF and 10nF capacitors. Do not connect other circuitry to this pin. 23 PSEN3 Power-Supply Enable Output #3.
PAGE 12
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MAX34441 Block Diagram VDD VSS REG25 VSS REG18 VSS POWER CONTROL PULSEWIDTH MODULATOR 2.5V VREG 1.
PAGE 13
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller +3.3V ALERT HOST INTERFACE CLOCK DATA CONTROL RST SDA SCL RST ALERT MAX34441 #0 FAULT CONTROL A1/PG/TACHSEL A0/MUXSEL +3.
PAGE 14
MAX34441 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.
PAGE 15
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller CODE COMMAND NAME TYPE PAGE 0–4 51h 5Eh 5Fh 60h 62h 64h 78h 79h 7Ah 7Eh 80h 81h 8Bh 8Ch 8Dh 90h 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh D1h D4h D5h D6h D7h D9h DAh DCh DDh E0h F0h F1h F2h F3h F5h F6h OT_WARN_LIMIT POWER_GOOD_ON POWER_GOOD_OFF TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_CML STATUS_MFR_SPECIFIC STATUS_FANS_1_2 READ_VOUT READ_IOUT READ_TEMPERATURE_1 READ_FAN_SPEED_1 PMBUS_REVISION MFR_ID MFR_MO
PAGE 16
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 1. PMBus Command Codes (continued) Note Note Note Note 3: 4: 5: 6: 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. The factory-set default value for this 8-byte block is 3130313031303130h.
PAGE 17
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller continuous data stream. All the devices addressed during this transaction wait for the host to issue a STOP before beginning to respond to the command.
PAGE 18
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Alert Response Address (ARA) Byte Format 1 7 S ARA 0001100 1 R 1 8 1 1 A DEVICE SLAVE ADDRESS WITH LSB = 0 NA P Host Sends or Reads Too Few Bits If for any reason the host does not complete writing a full byte or reading a full byte from the device before a START or STOP is received, 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.
PAGE 19
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 1) ACKs the address byte. 2) Ignores the command. 3) Sends all ones (FFh) as long as the host keeps acknowledging. 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). Host Writes to a Read-Only Command When a write request is issued to a read-only command, the device does the following: 1) Ignores the command.
PAGE 20
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 3.
PAGE 21
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 4. Coefficients for DIRECT Format Value COMMAND CODE COMMAND NAME m b R 25h VOUT_MARGIN_HIGH 1 0 0 8Bh READ_VOUT 1 0 0 The host sends the SMBus ARA (0001 100). The device ACKs the SMBus ARA, transmits its slave address, and deasserts ALERT. The system controller then communicates with PMBus commands to retrieve the fault/warning status information from the device. See the individual command sections for more details.
PAGE 22
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller particular fault. Table 5 illustrates the required conditions and fault actions for specific parameters. System Watchdog Timer The device uses an internal watchdog timer that is internally reset every 5ms. In the event that the device is locked up and this watchdog reset does not occur after 500ms, the device automatically resets.
PAGE 23
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller FAN CONTROL MODE FAN OPERATIONAL DETAILS BIT 6 OF _ FAN_CONFIG_1_2 VALUE IN _ FAN_COMMAND_1 Manual PWM External host controls the fan speed by directly setting the fan PWM duty cycle values. 0 0000h to 7FFFh Manual RPM External host controls the fan speed by setting target fan speed values. The device reads the actual fan speed, and close loop adjusts the output fan PWM to match the target fan speed.
PAGE 24
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller One or all of the six available temperature sensors can be used to control the fan speed. Each temperature sensor has an offset adjustment that allows monitoring specific temperature zones with different thermal characteristics. In Figure 1, I2C temperature sensor 0 is monitoring a zone that is 15NC more sensitive than the zone that the I2C temperature sensor 3 is measuring.
PAGE 25
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 100% SPIN-UP CRITERIA MET AUTOMATIC SPIN-UP ENABLED 90% When spin-up passes, the device forces the fan PWM with a 40% duty cycle. The 40% duty cycle is maintained until the next temperature conversion is completed, which occurs once a second. After the temperature conversion, the device enters either manual mode operation or automatic operation using MFR_FAN_LUT.
PAGE 26
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller PMBus Commands A summary of the PMBus commands supported by the device are described in the following sections. PAGE (00h) The device can control up to five power supplies, up to six temperature sensors, and a fan using one PMBus (I2C) address. Send the PAGE command with data 0 to 11 to select which power supply or which temperature sensor or fan is affected by all the PMBus commands shown in Table 1.
PAGE 27
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller USER NOTE: All power supplies tagged as GLOBAL supplies (see MFR_FAULT_RESPONSE) should be turned on and off at the same time. Table 9.
PAGE 28
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller ON_OFF_CONFIG (02h) The ON_OFF_CONFIG command configures the combination of CONTROL input and PMBus OPERATION commands needed to turn the power supply on and off. This indicates how the power supply is commanded when power is applied. Table 11 describes the ON_OFF_CONFIG message content. The host should not modify ON_OFF_CONFIG while the power supplies are active. Table 11.
PAGE 29
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller USER NOTE: VDD must be above 2.9V for the device to perform the STORE_DEFAULT_ALL command. RESTORE_DEFAULT_ALL (12h) The RESTORE_DEFAULT_ALL command transfers the default configuration information from the internal flash memory array to the user memory registers in the device. The RESTORE_DEFAULT_ALL command should only be executed when the device is not operating the power supplies or fans.
PAGE 30
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VOUT_MARGIN_LOW (26h) The VOUT_MARGIN_LOW command loads the device with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin low. If the power supply is already operating at margin low, changing VOUT_MARGIN_LOW has no effect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_LOW voltage after receiving a new margin low OPERATION command.
PAGE 31
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 15. FAN_CONFIG_1_2 Command Byte BIT NAME 7 FAN ENABLE 6 RPM/PWM 5:4 PULSE 3:0 0 MEANING 0 = Fan disabled (PWM5 forced low). 1 = Fan enabled. 0 = PWM duty cycle is the fan-controlling parameter. 1 = RPM is the fan-controlling parameter. 00 01 10 11 = = = = 1 2 3 4 Tach Tach Tach Tach pulse per fan revolution. pulses per fan revolution. pulses per fan revolution. pulses per fan revolution. These bits always return a 0.
PAGE 32
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VOUT_OV_FAULT_LIMIT (40h) The VOUT_OV_FAULT_LIMIT command sets the value of the output voltage that causes an output overvoltage fault. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the VOUT_OV bit in STATUS_BYTE. 2) Sets the VOUT_OV and VOUT bits in STATUS_WORD. 3) Sets the VOUT_OV_FAULT bit in STATUS_VOUT.
PAGE 33
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE, IOUT, and MFR bits in STATUS_WORD. 3) Sets the OC_WARN bit in STATUS_MFR_SPECIFIC. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). IOUT_OC_FAULT_LIMIT (4Ah) The IOUT_OC_FAULT_LIMIT command sets the value of the current that causes an overcurrent fault. The factory default value for IOUT_OC_FAULT_LIMIT is 0000h.
PAGE 34
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller OT_WARN_LIMIT (51h) The OT_WARN_LIMIT command sets the temperature, in degrees Celsius, of the selected temperature sensor at which an overtemperature warning is detected. The 2 data bytes are in DIRECT format. In response to the OT_WARN_LIMIT being exceeded, the device does the following: 1) Sets the TEMPERATURE bit in STATUS_BYTE. 2) Sets the TEMPERATURE and MFR bits in STATUS_WORD.
PAGE 35
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TON_MAX_FAULT_LIMIT (62h) The TON_MAX_FAULT_LIMIT sets an upper time limit, in milliseconds, from when the TON_DELAY and the PSEN output are asserted until the output voltage crosses the VOUT_UV_FAULT_LIMIT threshold. The 2 data bytes are in DIRECT format. If the value is 0, the power supply is not sequenced by the device and the associated PSEN output remains deasserted; voltage and current monitoring is disabled.
PAGE 36
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller STATUS_WORD (79h) The STATUS_WORD command returns 2 bytes of information with a summary of the reason for a fault. The low byte of the STATUS_WORD is the same data as the STATUS_BYTE. Table 21 describes the STATUS_WORD message content. Table 21. STATUS_WORD BIT BIT NAME 15 VOUT An output voltage fault or warning or TON_MAX_FAULT has occurred. 14 IOUT An overcurrent fault or warning has occurred.
PAGE 37
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 24. STATUS_MFR_SPECIFIC BIT BIT NAME 7 OFF MEANING This bit is set if the power supply is off (due to either a fault or sequencing delay; this bit is not set if the power supply is disabled). 6 OT_WARN Overtemperature warning. 5 OT_FAULT Overtemperature fault. 4 WATCHDOG A watchdog reset has occurred. 3 MARGIN_FAULT This bit is set if the device cannot properly close-loop margin the power supply.
PAGE 38
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller READ_FAN_SPEED_1 (90h) The READ_FAN_SPEED_1 command returns the fan speed in RPM. READ_FAN_SPEED_1 is updated once a second, even if the fan is disabled. The PULSE bits in FAN_CONFIG_1_2 must be properly configured to receive the correct fan speed. Fan speeds below 60 RPM (360 RPM for dual mode fans) are reported as 0 RPM. The 2 data bytes are in DIRECT format.
PAGE 39
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 26. MFR_MODE BIT BIT NAME MEANING FORCE_NV_FAULT_LOG Setting this bit to 1 forces the device to log data into the nonvolatile fault log. Once set, the device clears this bit when the action is completed. The host must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML.
PAGE 40
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_VOUT_PEAK (D4h) The MFR_VOUT_PEAK command returns the maximum actual measured output voltage. To reset this value to 0, write to this command with a data value of 0. Any values written to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. MFR_IOUT_PEAK (D5h) The MFR_IOUT_PEAK command returns the maximum measured current.
PAGE 41
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller RESPONSE [1:0] 11 FAULT RESPONSE • • • Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. Continue power-supply operation. • Shut down the power supply by deasserting the PSEN output. Wait for the time configured in MFR_FAULT_RETRY and restart the supply.
PAGE 42
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller EACH FAULT IS WRITTEN INTO THE NEXT FAULT LOG FLASH EACH COMMAND READ ACCESSES THE NEXT FAULT LOG FAULT LOG INDEX 0 (255 BYTES) RAM FAULT LOG INDEX 1 (255 BYTES) STATUS VOLTAGE CURRENT TEMPERATURE FAN SPEED FAULT OCCURENCE MFR_NV_FAULT_LOG FAULT LOG INDEX 2 (255 BYTES) FAULT LOG INDEX 14 (255 BYTES) Figure 5.
PAGE 43
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller BYTE 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 PARAMETER MFR_VOUT_PEAK Page 4 RESERVED (0000h) MFR_IOUT_PEAK Page 0 MFR_IOUT_PEAK Page 1 MFR_IOUT_PEAK Page 2 MFR_IOUT_PEAK Page 3 MFR_IOUT_PEAK Page 4 RESERVED (0000h) MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK
PAGE 44
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_TIME_COUNT (DDh) The MFR_TIME_COUNT command returns the number of seconds the device has been operating since the last time power was applied to the device, RST was toggled, or a soft reset occurred. The counter is a 32-bit value and cannot be reset by the user. MFR_MARGIN_CONFIG (E0h) The MFR_MARGIN_CONFIG command configures the digital PWM outputs to margin the power supplies.
PAGE 45
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 31. MFR_TEMP_SENSOR_CONFIG BIT 15 BIT NAME ENABLE MEANING 0 = Temperature sensor disabled. 1 = Temperature sensor enabled. The OFFSET setting is used to allow the temperature reading to be normalized among multiple temperature sensors. Values from 00h to 1Eh select the offset value. The valid range is 0NC to +30NC in 1NC steps.
PAGE 46
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_FAN_CONFIG (F1h) The MFR_FAN_CONFIG command is used with FAN_CONFIG_1_2 to configure the fan. See the FAN_CONFIG_1_2 description for more details on this command. Table 32 described the MFR_FAN_CONFIG command. Table 32. MFR_FAN_CONFIG BIT BIT NAME MEANING The FREQ bits set the PWM frequency. Note: The device does not support pulse stretching.
PAGE 47
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller BIT BIT NAME MEANING The RAMP bits select how fast the device ramps the PWM from one duty cycle to another (either up or down). In PWM mode, the following table always applies. In RPM mode, the fan speed is read either every 200ms or 1000ms and when the reported fan speed is within 20% of the target speed, the maximum allowed PWM duty cycle change is set to 1%.
PAGE 48
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_FAN_LUT (F2h) The MFR_FAN_LUT command is used to configure the LUT that controls the fan. The fan has an LUT that maps eight programmable temperature levels to eight programmable fan PWM duty-cycle levels (bit 6 in FAN_CONFIG_1_2 is zero) or eight programmable target fan speeds (bit 6 in FAN_CONFIG_1_2 is one). The LUT allows a wide variety of profiles to be used.
PAGE 49
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller If bit 6 in FAN_CONFIG_1_2 is set to 1, the FAN SPEED STEP sets the fan target speed (in RPM) at each temperature step breakpoint. The valid fan speed range is 0 to 32,767 (inclusive). THERMAL HYSTERESIS MAXIMUM DESIRED FAN DUTY CYCLE OR SPEED S7 S6 S5 S4 FAN PWM DUTY CYCLE OR FAN SPEED (IN RPM) S3 S2 S1 S0 PWM = 0% DUTY CYCLE T0 T1 T2 T3 T4 T5 T6 T7 NORMALIZED TEMPERATURE (FROM ONE OR MORE TEMP SENSORS) Figure 6.
PAGE 50
MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_READ_FAN_PWM (F3h) The MFR_READ_FAN_PWM command returns the latest real-time value for the fan PWM in % duty cycle. MFR_READ_FAN_PWM is updated whenever the PWM duty cycle is updated. This is determined by the RATE bits in MFR_FAN_CONFIG. The 2 data bytes are in DIRECT format.
PAGE 51
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Power-Supply Decoupling To achieve the best results when using the device, decouple the VDD power supply with a 0.1FF capacitor. Use a high-quality, ceramic, surface-mount capacitor if possible. Surface-mount components minimize lead inductance, which improves performance, and ceramic capacitors tend to have adequate high-frequency response for decoupling applications.
PAGE 52
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MAX34441 Typical Operating Circuit INPUT VOLTAGE IN OUT POWER SUPPLY MAX9938 CURRENT-SENSE AMPLIFIER TRIM EN UP TO 4 CHANNELS MSCL +3.
PAGE 53
PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller REVISION NUMBER REVISION DATE 0 8/10 Initial release 1/12 Changed the lead temperature from +260°C to +300°C in the Absolute Maximum Ratings section; changed the VIL(MIN) and VI2C_IL(MIN) specs from -0.