MAX15303 PMBus Command Set User’s Guide Rev 0; 1/14 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 © 2014 Maxim Integrated Products, Inc.
MAX15303 PMBus Command Set User’s Guide Introduction Maxim Integrated InTune™ digital power products utilize the PMBus™ command standard for configuration, control, and telemetry. This document lists and describes the PMBus commands implemented in the MAX15303 digital DC-DC converter. Standard commands from the PMBus specification are not described in detail unless there are deviations from the PMBus specification functionality. Maxim manufacturer-specific commands are fully described in this document.
MAX15303 PMBus Command Set User’s Guide VOUT_DROOP ........................................................................................................................................................................ 12 Switching Frequency and PWM Commands .............................................................................................................................. 14 FREQUENCY_SWITCH..........................................................................................................
MAX15303 PMBus Command Set User’s Guide Telemetry Commands................................................................................................................................................................ 29 READ_VIN .............................................................................................................................................................................. 29 READ_VOUT .............................................................................................
MAX15303 PMBus Command Set User’s Guide STORE_DEFAULT_ALL ............................................................................................................................................................ 42 RESTORE_DEFAULT_ALL ........................................................................................................................................................ 43 STORE_USER_ALL........................................................................................................
MAX15303 PMBus Command Set User’s Guide On, Off, and Margin Testing-Related Commands OPERATION Reference: Command Code: Data Bytes: Transfer: Standard Command 0x01 1 Read/Write Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 12.1 of the PMBus Specification Part II.
MAX15303 PMBus Command Set User’s Guide ON_OFF_CONFIG Reference: Command Code: Data Bytes: Transfer: Standard Command 0x02 1 Read/Write Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 12.2 of the PMBus Specification Part II.
MAX15303 PMBus Command Set User’s Guide VIN_OFF Description/Notes: See Section 14.6 of the PMBus Specification Part II. The MAX15303 hardware has 8-bit resolution for the minimum input voltage required for regulation, to a maximum value of ≈14.75V. The desired value of VIN_OFF is retained in memory, regardless limitations imposed by the 8-bit fault limit resolution, but the read-back value is based on actual hardware register settings.
MAX15303 PMBus Command Set User’s Guide Output Voltage-Related Commands VOUT_MODE Reference: Command Code: Data Bytes: Transfer: Standard Command 0x20 1 Read Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 8.2 of the PMBus Specification Part II. No Mixed: bit-field and two’s complement N/A 0x14 (Linear Mode, exponent -12) The MAX15303 only supports Linear Mode values for output voltage related commands. The VOUT_MODE command is read-only and the value cannot be changed.
MAX15303 PMBus Command Set User’s Guide VOUT_TRIM VOUT_CAL_OFFSET, and the result is sent to the control loop as the output voltage setpoint. Note that in the MAX15303, VOUT_TRIM is sent as a PMBus Linear value, rather than as a two’s complement binary integer mantissa as specified in the PMBus standard, to avoid introducing another numeric format. The value of VOUT_TRIM is not subtracted from READ_VOUT, so non-zero VOUT_TRIM values will result in a difference between VOUT_COMMAND and READ_VOUT.
MAX15303 PMBus Command Set User’s Guide VOUT_MARGIN_HIGH Reference: Command Code: Data Bytes: Transfer: Standard Command 0x25 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 13.6 of the PMBus Specification Part II. Yes Unsigned integer mantissa V 0x14CD (1.300V) VOUT_MARGIN_HIGH mantissa data sent to and from the MAX15303 must be divided by 4096 to determine the actual voltage value, according to the fixed value of VOUT_MODE. The factory value of 0x14CD (1.
MAX15303 PMBus Command Set User’s Guide VOUT_TRANSITION_RATE Reference: Command Code: Data Bytes: Transfer: Standard Command 0x27 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 13.8 of the PMBus Specification Part II. Yes Linear mV/μs (or V/ms, kV/s) 0x9B33 (0.1V/ms, see Description) To achieve output voltage slew-rate control, the MAX15303 has an 8-bit timer with approximately 243ns resolution.
MAX15303 PMBus Command Set User’s Guide VOUT_DROOP accurate adaptive voltage positioning results with the VOUT_DROOP command. Note that VOUT_DROOP can accept negative resistance values, allowing a user to compensation for resistive losses between the output voltage remote sense point and the load, if desired. (Setting VOUT_DROOP to a negative value will case output voltage to rise with increasing load.
MAX15303 PMBus Command Set User’s Guide Switching Frequency and PWM Commands FREQUENCY_SWITCH Reference: Command Code: Data Bytes: Transfer: Standard Command 0x33 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 14.4 of the PMBus Specification Part II.
MAX15303 PMBus Command Set User’s Guide INTERLEAVE ADDR1 pins, unless a new value of INTERLEAVE has been written to the User Store. The value of the ADDR0 and ADDR1 pin resistance is measured only once during initialization (power-up). Because the MAX15303 uses one of two different PWM “speed modes” depending on the switching frequency selected (see FREQUENCY_SWITCH), the INTERLEAVE command will show unexpected results if switching frequency crosses the 475kHz speed-mode boundary after initialization.
MAX15303 PMBus Command Set User’s Guide Output Voltage Sequencing Commands POWER_GOOD_ON Reference: Command Code: Data Bytes: Transfer: Standard Command 0x5E 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 15.32.1 of the PMBus Specification Part II. Yes Unsigned integer mantissa V 0x1135 (1.080V) POWER_GOOD_ON mantissa data sent to and from the MAX15303 must be divided by 4096 to determine the actual voltage value, according to the fixed value of VOUT_MODE.
MAX15303 PMBus Command Set User’s Guide TON_DELAY Reference: Command Code: Data Bytes: Transfer: Standard Command 0x60 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 16.1 of the PMBus Specification Part II. Yes Linear ms 0xCA80 (5ms) The TON_DELAY command sets the delay time between a valid enable condition and the beginning of the output ramp to regulation at VOUT_COMMAND. The nominal factory value is 5ms.
MAX15303 PMBus Command Set User’s Guide TOFF_FALL Reference: Command Code: Data Bytes: Transfer: Standard Command 0x65 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 16.6 of the PMBus Specification Part II. Yes Linear ms 0xCA80 (5ms) The TOFF_FALL command sets the ramp-down time from regulation at VOUT_COMMAND to 0V. The nominal factory value is 5ms.
MAX15303 PMBus Command Set User’s Guide Fault-Related Commands CLEAR_FAULTS Reference: Command Code: Data Bytes: Transfer: Standard Command 0x03 0 Send Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 15.1 of the PMBus Specification Part II. Yes N/A N/A N/A If the MAX15303 has latched off for a fault condition, sending the CLEAR_FAULTS command will cause a restart.
MAX15303 PMBus Command Set User’s Guide VOUT_OV_FAULT_RESPONSE 10 11 fault does not abate, shutdown and attempt to restart according to bits [5:3]. Stop regulating immediately, delay for the time specified in bits [2:0], then attempt to restart according to bits [5:3]. (Default setting) Stop regulating immediately, and then restart as soon as possible after the fault condition abates. Bits [5:3] determine the number of retry attempts.
MAX15303 PMBus Command Set User’s Guide VOUT_UV_FAULT_RESPONSE The VOUT_UV_FAULT_RESPONSE command data comprises three bit-fields: Bits [7:6] determine the basic fault-response mode. The MAX15303 supports the following modes: 00 01 10 11 Ignore the fault condition. (Default setting) Continue operating and wait for the fault to abate for time specified in bits [2:0]. If the fault does not abate, shutdown and attempt to restart according to bits [5:3].
MAX15303 PMBus Command Set User’s Guide IOUT_OC_FAULT_RESPONSE • • MAX15303 does not support finite, non-zero restart-attempt counts. (Continuous restart attempts are supported.) MAX15303 also does not support the “delay before shutdown” (sometimes referred to as “wait for abate”) option for overcurrent faults. The IOUT_OC_FAULT_RESPONSE command data comprises three bit-fields: Bits [7:6] determine the basic fault-response mode.
MAX15303 PMBus Command Set User’s Guide OT_FAULT_RESPONSE Reference: Command Code: Data Bytes: Transfer: Standard Command 0x50 1 Read/Write Byte Lockable: Format: Units: Factory Value: Description/Notes: See Sections 10.5.1 and 15.18 of the PMBus Specification Part II. Yes Bit field N/A 0xC0 (Shut down, restart when fault abates) Note that the MAX15303 does not support finite, non-zero restart-attempt counts. (Continuous restart attempts are supported.
MAX15303 PMBus Command Set User’s Guide OT_WARN_LIMIT temperature signal instead. Overtemperature fault hysteresis is achieved in the MAX15303 by using the OT_WARN_LIMIT as the “fault cleared” threshold for OT_FAULT_LIMIT. For this reason, it is important to always set OT_WARN_LIMIT below OT_FAULT_LIMIT. VIN_OV_FAULT_LIMIT Reference: Command Code: Data Bytes: Transfer: Standard Command 0x55 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 15.
MAX15303 PMBus Command Set User’s Guide VIN_OV_FAULT_RESPONSE Bits [2:0] determine the fault-tolerance or retry-delay timing. Each binary value in bits [2:0] corresponds to a multiple of 100ms, up to a possible maximum of 111bin = 700ms. A value of 000bin will cause the MAX15303 to use the minimum possible timing value, typically about 30-40ms. (The default timing for input overvoltage faults is 000bin.
MAX15303 PMBus Command Set User’s Guide VIN_UV_FAULT_RESPONSE corresponds to a multiple of 100ms, up to a possible maximum of 111bin = 700ms. A value of 000bin will cause the MAX15303 to use the minimum possible timing value, typically about 30-40ms. (The default timing for input undervoltage faults is 000bin.
MAX15303 PMBus Command Set User’s Guide Unit Status Commands STATUS_BYTE Reference: Command Code: Data Bytes: Transfer: Standard Command 0x78 1 Read Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 17.1 of the PMBus Specification Part II. N/A Bit field N/A N/A STATUS_WORD Reference: Command Code: Data Bytes: Transfer: Standard Command 0x79 2 Read Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 17.2 of the PMBus Specification Part II.
MAX15303 PMBus Command Set User’s Guide STATUS_INPUT Reference: Command Code: Data Bytes: Transfer: Standard Command 0x7C 1 Read Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 17.5 of the PMBus Specification Part II. N/A Bit field N/A N/A Bits #6, #5, #2, #1, and #0 are not implemented in the MAX15303 because the corresponding fault commands are not supported.
MAX15303 PMBus Command Set User’s Guide Telemetry Commands READ_VIN Reference: Command Code: Data Bytes: Transfer: Standard Command 0x88 2 Read Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 18.1 of the PMBus Specification Part II. N/A Linear V N/A The MAX15303 has 12-bit measurement resolution for input voltage to a maximum value of about 14.75V.
MAX15303 PMBus Command Set User’s Guide READ_TEMPERATURE_1 Reference: Command Code: Data Bytes: Transfer: Standard Command 0x8D 2 Read Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 18.6 of the PMBus Specification Part II. N/A Linear °C N/A The MAX15303 uses READ_TEMPERATURE_1 to report its internal (i.e., die) temperature.
MAX15303 PMBus Command Set User’s Guide READ_FREQUENCY The READ_FREQUENCY command returns the actual switching frequency in kilohertz. The desired switching frequency is set using the FREQUENCY_SWITCH command.
MAX15303 PMBus Command Set User’s Guide PMB_VALUES PAGE 33MAX15303 PMBus Command Set User’s Guide Calibration Commands IOUT_CAL_GAIN Reference: Command Code: Data Bytes: Transfer: Standard Command 0x38 2 Read/Write Word Lockable: Format: Units: Factory Value: Description/Notes: See Section 14.8 of the PMBus Specification Part II. Yes Linear mΩ 0xB200 (0.
MAX15303 PMBus Command Set User’s Guide EXT_TEMP_CAL EXT_TEMP_CAL signal are as follows: Data Byte Number Data Byte Name Units 0 m None 1 2 b IoutTC °K ∆/°C Description Combined temperature gain correction and diode ideality factor Temperature offset correction Current-sense element temperature coefficient of resistivity Temperature Calibration When reading or writing the EXT_TEMP_CAL command data, note that only the decimal portion of the gain correction term (data byte 0) is sent to allow greate
MAX15303 PMBus Command Set User’s Guide Device Identification Commands CAPABILITY Reference: Command Code: Data Bytes: Transfer: Standard Command 0x19 1 Read Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 11.12 of the PMBus Specification Part II. N/A Bit field N/A 0xA0 PMBUS_REVISION Reference: Command Code: Data Bytes: Transfer: Standard Command 0x98 1 Read Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 22.
MAX15303 PMBus Command Set User’s Guide MFR_MODEL Reference: Command Code: Data Bytes: Transfer: Standard Command 0x9A 13 Read/Write Block Lockable: Format: Units: Factory Value: Description/Notes: See Section 22.2.2 of the PMBus Specification Part II. Yes ASCII string N/A String of 13 spaces (ASCII 0x20) Note that the MAX15303 implements MFR_MODEL as a fixed-width string, not as part of a shared memory space.
MAX15303 PMBus Command Set User’s Guide MFR_SERIAL Reference: Command Code: Data Bytes: Transfer: Standard Command 0x9E 13 Read/Write Block Lockable: Format: Units: Factory Value: Description/Notes: See Section 22.2.6 of the PMBus Specification Part II. Yes ASCII string N/A String of 13 spaces (ASCII 0x20) Note that the MAX15303 implements MFR_SERIAL as a fixed-width string, not as part of a shared memory space.
MAX15303 PMBus Command Set User’s Guide Security Commands WRITE_PROTECT Reference: Command Code: Data Bytes: Transfer: Standard Command 0x10 1 Read/Write Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 11.1 of the PMBus Specification Part II.
MAX15303 PMBus Command Set User’s Guide MANUF_LOCK Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xE1 2 Write Word Lockable: Format: Units: Factory Value: Yes Direct N/A 0x0000 Description/Notes: The MANUF_LOCK command contains the password value for the “manufacturer” PMBus command security level.
MAX15303 PMBus Command Set User’s Guide USER_CONF memory value of USER_LOCK, then the MAX15303 will ignore attempts to write data to that command. Note that setting a bit for a read-only PMBus command or send-byte PMBus command has no effect, regardless of SECURITY_LEVEL. Likewise, read operations for any PMBus command are never blocked on the basis of USER_CONF and SECURITY_LEVEL. The 32 data bytes for USER_CONF are saved in flash memory as a unique, single instance (i.e.
MAX15303 PMBus Command Set User’s Guide SECURITY_LEVEL Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xE6 1 Read Byte Description/Notes: The MAX15303 provides two levels of password protection for all writable PMBus commands, on a per-command basis.
MAX15303 PMBus Command Set User’s Guide Memory and Storage Commands STORE_DEFAULT_ALL Reference: Command Code: Data Bytes: Transfer: Standard Command 0x11 0 Send Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 11.2 of the PMBus Specification Part II. Yes N/A N/A N/A The MAX15303 includes three banks of nonvolatile (flash memory) storage for most “writable” PMBus command values, referred to as the USER, DEFAULT, and MAXIM stores.
MAX15303 PMBus Command Set User’s Guide RESTORE_DEFAULT_ALL Reference: Command Code: Data Bytes: Transfer: Standard Command 0x12 0 Send Byte Lockable: Format: Units: Factory Value: Description/Notes: See Section 11.3 of the PMBus Specification Part II. Yes N/A N/A N/A The MAX15303 includes three banks of nonvolatile (flash memory) storage for most “writable” PMBus command values, referred to as the USER, DEFAULT, and MAXIM stores. These stores are fully independent, but identical in structure.
MAX15303 PMBus Command Set User’s Guide STORE_USER_ALL independently in nonvolatile memory for security. MANUF_PASSWD The manufacturer security password is always volatile for obvious reasons. USER_CONF The user flags for password command locking are stored independently in nonvolatile memory for security. USER_PASSWD The user security password is always volatile for obvious reasons.
MAX15303 PMBus Command Set User’s Guide RESTORE_MAXIM_ALL Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xEA 0 Send Byte Lockable: Format: Units: Factory Value: Yes N/A N/A N/A Description/Notes: The MAX15303 includes three banks of nonvolatile (flash memory) storage for most “writable” PMBus command values, referred to as the USER, DEFAULT, and MAXIM stores. These stores are fully independent, but identical in structure.
MAX15303 PMBus Command Set User’s Guide STRAP_DISABLE 16 VOUT_TRIM 15 INTERLEAVE 14 COMP_MODEL 13 12 11 10 9 8 7 6 5 4 3 2 1 0 VOUT_MAX IOUT_CAL_GAIN FREQUENCY_SWITCH IOUT_OC_FAULT_LIMIT VOUT_MARGIN_LOW VOUT_MARGIN_HIGH POWER_GOOD_OFF POWER_GOOD_ON VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_OV_FAULT_LIMIT VOUT_COMMAND No function; intended to support a possible pin-strap voltage trimming scheme that was never implemented.
MAX15303 PMBus Command Set User’s Guide Control Loop Commands ADAPTIVE_MODE Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xD0 2 Read/Write Word Description/Notes: The ADAPTIVE_MODE command configures the automatic tuning features of the MAX15303.
MAX15303 PMBus Command Set User’s Guide FEEDBACK_EFFORT Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xD3 2 Read Byte Lockable: Format: Units: Factory Value: Yes Linear Scalar 0xB200 (0.5) Description/Notes: This command allows some user adjustment of the tradeoff between transient response, load regulation, and output noise. The default value is 0.5, which provides a good balance of transient response performance and output noise characteristics.
MAX15303 PMBus Command Set User’s Guide COMP_MODEL Reference: Command Code: Data Bytes: Transfer: Maxim Specific 0xDB 6 (see Description) Read/Write Block Lockable: Format: Units: Factory Value: Description/Notes: The COMP_MODEL command provides access to key control loop tuning parameters. The three arguments are as follows: Data Byte Number Data Byte Name Units 0 FLC/FSW None 1 FZ/FSW None 2 ZLC None Yes Linear Scalar 0.025, 0.41666, 1.
MAX15303 PMBus Command Set User’s Guide DEADTIME_GCTRL 7 TDF (MSB) 8 LXDAC 9 GCTRL[0] 10 GCTRL[1] 11 GCTRL[2] 12 GCTRL[3] 13 GCTRL[4] 14 GCTRL[5] 15 GCTRL[6] 16 GCTRL[7] 17 18 GCTRLDAC (LSB) GCTRLDAC (MSB) Integer Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Byte Unsigned Integer (AGD system disabled, do not alter this value) (AGD system disabled, do not alter this value) 15 Function disabled; not applicable
MAX15303 PMBus Command Set User’s Guide ZETA_P Data Bytes: Transfer: 2 Read/Write Byte Units: Factory Value: Scalar 0xBB00 (1.5) Description/Notes: The ZETA_P command sets the damping ratio for the closed-loop response. The value can be changed to improve performance when using non-ceramic output capacitors with higher equivalent series resistance. Wait at least 500μs for execution after sending the ZETA_P command before sending additional PMBus commands.
MAX15303 PMBus Command Set User’s Guide Revision History REVISION NUMBER 0 REVISION DATE 1/14 DESCRIPTION Initial release PAGES CHANGED — Page 52 of 52