EVALUATION KIT AVAILABLE MAX34440 PMBus 6-Channel Power-Supply Manager General Description The MAX34440 is a complex system monitor that can manage up to six power supplies. 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 userprogrammable level.
MAX34440 PMBus 6-Channel Power-Supply Manager TABLE OF CONTENTS Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAX34440 PMBus 6-Channel Power-Supply Manager TABLE OF CONTENTS (continued) PMBus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 PAGE (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 OPERATION (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAX34440 PMBus 6-Channel Power-Supply Manager TABLE OF CONTENTS (continued) MFR_MODEL (9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_REVISION (9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_LOCATION (9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAX34440 PMBus 6-Channel Power-Supply Manager LIST OF FIGURES Figure 1. Power-Supply Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 2. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 LIST OF TABLES Table 1. PMBus Command Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAX34440 PMBus 6-Channel Power-Supply Manager ABSOLUTE MAXIMUM RATINGS Operating Temperature Range........................... -40NC to +85NC Storage Temperature Range............................. -55NC to +125NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC VDD to VSS............................................................-0.3V to +5.5V RS- to VSS.......................................................
MAX34440 PMBus 6-Channel Power-Supply Manager 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 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.
MAX34440 PMBus 6-Channel Power-Supply Manager 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 SCL Clock Frequency fSCL Bus Free Time Between STOP and START Conditions tBUF Hold Time (Repeated) START Condition CONDITIONS MIN TYP 10 (Note 5) MAX UNITS 100 kHz 1 ms tHD:STA 4.0 Fs Low Period of SCL tLOW 4.
MAX34440 PMBus 6-Channel Power-Supply Manager Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE 2.5 2.5 2.4 IDD (mA) 2.4 IDD (mA) MAX34440 toc02 2.6 MAX34440 toc01 2.6 2.3 VDD = 3.3V 2.3 TA = +25°C 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.
MAX34440 PMBus 6-Channel Power-Supply Manager VSS REG18 PSEN3 PWM2 PWM1 PSEN2 PSEN1 PWM0 TOP VIEW REG25 PSEN0 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 PSEN5 CONTROL 35 16 PWM5 MAX34440 VSS 36 15 MSCL A1/PG 37 14 MSDA ALERT 38 RS-5 39 13 RST EP + 12 RS-2 11 RS+2 5 6 VSS RS+4 RS-3 RS+3 RS+0 7 8 9 10 RS-1 4 VDD 3 RS-0 2 RS+1 1 RS-4 RS+5 40 TQFN (6mm × 6mm × 0.
MAX34440 PMBus 6-Channel Power-Supply Manager Pin Description (continued) PIN NAME FUNCTION 18 PWM4 PWM Margin Output #4. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 19 PSEN4 Power-Supply Enable Output #4. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. 20 PWM3 PWM Margin Output #3. High impedance when the margining is disabled.
MAX34440 PMBus 6-Channel Power-Supply Manager Pin Description (continued) PIN NAME 39 RS-5 Ground Reference for ADC5 Voltage Measurement FUNCTION 40 RS+5 Power-Supply ADC Voltage-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.
MAX34440 PMBus 6-Channel Power-Supply Manager Multiple Device Connection Diagram +3.3V ALERT HOST INTERFACE CLOCK DATA CONTROL RST SDA SCL RST ALERT MAX34440 #0 FAULT CONTROL A1/PG A0/MUXSEL +3.
MAX34440 PMBus 6-Channel Power-Supply Manager Detailed Description the supplies in any order at both power-up and powerdown. With the addition of an external current-sense amplifier, the device can also monitor currents. The MAX34440 is a highly integrated system monitor based upon a 16-bit MAXQM microcontroller with factory-programmed functionality to monitor up to six power supplies. The device provides power-supply closed-loop control, and local/remote thermal-sensing facilities.
MAX34440 PMBus 6-Channel Power-Supply Manager Table 1. PMBus Command Codes (continued) CODE COMMAND NAME TYPE PAGE 0–5 PAGE 6–13 PAGE 255 (NOTE 1) NO.
MAX34440 PMBus 6-Channel Power-Supply Manager Table 2. PMBus/SMBus Serial-Port Address 7-BIT SLAVE ADDRESS A1 A0 100kI to VSS 100kI to VSS 100kI to VDD 100kI to VDD 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 1101 010 (D4h) The device implements the PMBus command structure using the SMBus format.
MAX34440 PMBus 6-Channel Power-Supply Manager Group Command The device supports the group command. With the group command, a host can write different data to multiple devices on the same serial bus with one long 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.
MAX34440 PMBus 6-Channel Power-Supply Manager 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.
MAX34440 PMBus 6-Channel Power-Supply Manager Host Reads from a Write-Only Command 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 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).
MAX34440 PMBus 6-Channel Power-Supply Manager Table 3.
MAX34440 PMBus 6-Channel Power-Supply Manager Fault Management and Reporting For reporting faults/warnings to the host on a real-time basis, the device asserts the open-drain ALERT pin (if enabled in MFR_MODE) and sets the appropriate bit in the various status registers. On recognition of the ALERT assertion, the host or system manager is expected to poll the I2C bus to determine the device asserting ALERT. The host sends the SMBus ARA (0001 100).
MAX34440 PMBus 6-Channel Power-Supply Manager Temperature Sensor Operation The device can monitor up to eight different temperature sensors, seven external sensors plus its own internal temperature sensor. The external temperature sensors are all connected in parallel to the master I2C port (MSDA and MSCL pins). The device can support up to four DS75LV devices plus one MAX6695 device. Each of the enabled temperature sensors is measured once a second.
MAX34440 PMBus 6-Channel Power-Supply Manager 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 six power supplies and up to eight temperature sensors using one PMBus (I2C) address. Send the PAGE command with data 0 to 13 to select which power supply or which temperature sensor is affected by all the PMBus commands shown in Table 1. Not all commands are supported within each page.
MAX34440 PMBus 6-Channel Power-Supply Manager OPERATION (01h) The OPERATION command is used to turn the power supply on and off in conjunction with the CONTROL input pin. The OPERATION command is also used to cause the power supply to set the output voltage to the upper or lower margin voltages. The power supply stays in the commanded operating mode until a subsequent OPERATION command or until a change in the state of the CONTROL pin (if enabled) instructs the power supply to change to another state.
MAX34440 PMBus 6-Channel Power-Supply Manager 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 10 describes the ON_OFF_CONFIG message content. The host should not modify ON_OFF_CONFIG while the power supplies are active. Table 10.
MAX34440 PMBus 6-Channel Power-Supply Manager STORE_DEFAULT_ALL (11h) The STORE_DEFAULT_ALL command instructs the device to transfer the device configuration information to the internal flash memory array. Not all information is stored. Only configuration data is stored, not any status, or operational data. If an error occurs during the transfer, ALERT asserts if enabled and the CML bit in STATUS_BYTE and STATUS_WORD is set to 1. No bits are set in STATUS_CML.
MAX34440 PMBus 6-Channel Power-Supply Manager 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.
MAX34440 PMBus 6-Channel Power-Supply Manager USER NOTE: On the device, the full-scale ADC voltage is 1.225V. The value of the sense resistor and currentsense amplifier gain must be scaled appropriately. 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.
MAX34440 PMBus 6-Channel Power-Supply Manager 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). IOUT_OC_WARN_LIMIT (46h) The IOUT_OC_WARN_LIMIT command sets the value of the current that causes an overcurrent warning. This value is typically less than the overcurrent fault threshold in IOUT_OC_FAULT_LIMIT. The 2 data bytes are in DIRECT format.
MAX34440 PMBus 6-Channel Power-Supply Manager 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). 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.
MAX34440 PMBus 6-Channel Power-Supply Manager All the enabled power supplies must also be above POWER_GOOD_ON for power-supply margining to begin. The POWER_GOOD_ON level is normally set higher than the POWER_GOOD_OFF level and VOUT_UV_FAULT_LIMIT. The 2 data bytes are in DIRECT format. POWER_GOOD_OFF (5Fh) The POWER_GOOD_OFF command sets the value of the output voltage that causes the PG output to deassert after it has been asserted.
MAX34440 PMBus 6-Channel Power-Supply Manager immediately (either through the OPERATION command or the CONTROL pin), the TOFF_DELAY value is ignored. The 2 data bytes are in DIRECT format. STATUS_BYTE (78h) The STATUS_BYTE command returns 1 byte of information with a summary of the most critical faults. A value of 1 indicates that a fault or warning event has occurred and a 0 indicates otherwise. Bits for unsupported features are reported Table 16.
MAX34440 PMBus 6-Channel Power-Supply Manager 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 17 describes the STATUS_WORD message content. Table 18. STATUS_VOUT BIT BIT NAME 7 VOUT_OV_FAULT VOUT overvoltage fault. MEANING 6 VOUT_OV_WARN VOUT overvoltage warning. 5 VOUT_UV_WARN VOUT undervoltage warning. 4 VOUT_UV_FAULT VOUT undervoltage fault.
MAX34440 PMBus 6-Channel Power-Supply Manager The STATUS_MFR_SPECIFIC command returns 1 byte of information with a summary of the reason for a fault. The STATUS_MFR_SPECIFIC message content is described in Table 20. READ_VOUT (8Bh) The READ_VOUT command returns the actual measured (not commanded) output voltage. READ_VOUT is measured and updated every 5ms. The 2 data bytes are in DIRECT format. READ_IOUT (8Ch) The READ_IOUT command returns the latest measured current value.
MAX34440 PMBus 6-Channel Power-Supply Manager The MFR_SERIAL command loads the device with text (ISO/IEC 8859-1) characters that uniquely identify the device. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 10101010. Table 21. MFR_MODE BIT BIT NAME MEANING 15 Setting this bit to 1 forces the device to log data into the nonvolatile fault log.
MAX34440 PMBus 6-Channel Power-Supply Manager MFR_MODE (D1h) The MFR_MODE command is used to configure the device to support manufacturer specific commands. The MFR_ MODE command is described in Table 21. After this command is sent, another commmand should not be sent for at least 250ms. 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.
MAX34440 PMBus 6-Channel Power-Supply Manager Table 23. MFR_FAULT_RESPONSE Codes RESPONSE SETTING [1:0] 11 10 01 00 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. • • • Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1.
MAX34440 PMBus 6-Channel Power-Supply Manager 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 FAULT OCCURENCE MFR_NV_FAULT_LOG FAULT LOG INDEX 2 (255 BYTES) FAULT LOG INDEX 14 (255 BYTES) Figure 2. MFR_NV_FAULT_LOG There is a FAULT_LOG_COUNT (16-bit counter) at the beginning of each fault log that indicates which fault log is the latest.
MAX34440 PMBus 6-Channel Power-Supply Manager Table 24.
MAX34440 PMBus 6-Channel Power-Supply Manager If an error occurs while the device is attempting to write or clear the NV_FAULT_LOG, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. ALERT is asserted (if enabled in MFR_MODE). See Figure 2. USER NOTE: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG.
MAX34440 PMBus 6-Channel Power-Supply Manager Table 26. MFR_TEMP_SENSOR_CONFIG BIT BIT NAME 15 ENABLE 14:0 0 MEANING Clearing and setting this bit reinitializes the temperature sensor. 0 = Temperature sensor disabled. 1 = Temperature sensor enabled. These bits always return a 0. 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. Decouple the REG18 regulator outputs using 1FF and 10nF capacitors.
MAX34440 PMBus 6-Channel Power-Supply Manager Typical Operating Circuit INPUT VOLTAGE IN MAX6695 TWO REMOTE AND ONE LOCAL OUT POWER SUPPLY MAX9938 CURRENT-SENSE AMPLIFIER TRIM EN LOAD SPDT MUX OPTIONAL SUPPORT FOR CURRENT MONITORING 6 CHANNELS PSEN0 PWM0 RS-0 RS+0 MSDA DS75LV I2C TEMP SENSOR MSCL +3.3V PSEN1 PWM1 RS-1 RS+1 VDD VSS SDA SCL HOST INTERFACE FROM MUXSEL MAX34440 RST ALERT FAULT A0/MUXSEL A1/PG VOLTAGES SHOULD BE SCALED TO MATCH THE 1.225V FULL SCALE ADC VOLTAGE.
MAX34440 PMBus 6-Channel Power-Supply Manager Revision History REVISION NUMBER REVISION DATE 0 9/10 Initial release 1 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.