For more information, please visit the product page. date 11/07/2014 page 1 of 13 MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER GENERAL CHARACTERISTICS • • • • • • • • • • 4.5~14 V input range 0.6~5.0 V programmable output voltage tracking voltage margining Snapshot™ parametric capture voltage/current/temperature monitoring synchronization and phase spreading remote differential voltage sense programmable soft start and soft stop fault management MODEL FEATURES • compact package vertical: 20.8 x 7.23 x 15.6 mm (0.820 x 0.285 x 0.614 x in) • 12 A output • high efficiency • auto compensation • SMBus interface • PMBus™ Compatible • Ericsson footprint compatible input voltage NDM2Z-12V output voltage output current output wattage (Vdc) (Vdc) max (A) max (W) 4.5~14 0.6~5.0 12 60 PART NUMBER KEY NDM2Z-12V - X X - XXX Base Number Pin Configuration: A = standard configuration Package Option: A = loose parts B = tape and reel C = tray Firmware Configuration: 000~ZZZ Example part number: NDM2Z-12V-AA-002 vertical module standard pin configuration loose parts package option firmware configuration 002 CONTENTS Absolute Maximum Ratings.................................2 Recommended Operating Conditions....................2 Pin Descriptions................................................3 Typical Characteristics.......................................4~5 Mechanical Drawing..............................................6 Operating Information.....................................7~13 cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 2 of 13 ABSOLUTE MAXIMUM RATINGS parameter conditions/description min Vin input voltage digital pin voltage CTRL, DDC, SA0, SALRT, SDA, SCL, SYNC, VSET -0.3 analog pin voltage +S, -S, VTRK -0.3 6.5 V ground voltage differential (GND - PREF) -0.3 0.3 V operating temperature TP1 -40 120 °C -55 125 °C storage temperature typ max units 15 V 6.5 V RECOMMENDED OPERATING CONDITIONS -30°C < TP1 < +95°C, 4.5 V < Vin < 14 V, typical measurements made at Vin = 12 V, Vout = 1.0 V, Iout = Imax, TP1 = 25°C, =Cin = 470 μF/10 mΩ, Cout = 470 μF/8 mΩ INPUT / OUTPUT parameter conditions/description min max units Vin input supply voltage 4.5 14 V Iout output current 0 12 A Vout adjustable via resistor or PMBus™ commands 0.6 5.0 V Vout margin adjustable via PMBus commands 0 110 % voltage accuracy over line, load and temperature measured at +S and -S -1 1 % line regulation 4.5 Vout Vout Vout Vout load regulation 0 A ≤ Iout ≤ Imax Vout = 0.6 V Vout = 1.0 V Vout = 1.8 V Vout = 3.3 V voltage set-point resolution when Vout set via PMBus commands voltage ripple and noise Vout Vout Vout Vout ramp-up time adjustable via PMBus 0 200 ms on time delay adjustable via PMBus 5 500,000 ms load transient voltage deviation Iout: 25% Vout = 0.6 Vout = 1.0 Vout = 1.8 Vout = 3.3 V V V V load transient recovery time1 Iout: 25% Vout = 0.6 Vout = 1.0 Vout = 1.8 Vout = 3.3 V V V V Notes: V ≤ Vin ≤ 14 V = 0.6 V = 1.0 V = 1.8 V = 3.3 V = = = = 0.6 1.0 1.8 3.3 typ 0.3 0.6 0.4 2.2 mV 2.8 2.3 2.0 3.1 -0.025 V V V V mV 0.025 9 14 17 16 75% 75% 25% of Imax, dI/dt=2 A/μs 25% of Imax, dI/dt=2 A/μs 1. settling to within 3% of Vout cui.com 31 38 52 85 TBD 20 0 0 % FS mVp-p mV µs For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 3 of 13 POWER / EFFICIENCY parameter conditions/description min output power Vout = 5.0 V + 10% margin 0 max units 66 W Iout = 50% of max Vout Vout Vout Vout = = = = 0.6 1.0 1.8 3.3 V V V V 83.6 87.9 90.4 90.8 % Iout = max Vout Vout Vout Vout = = = = 0.6 1.0 1.8 3.3 V V V V 81.1 86.5 89.8 91.2 % 0.45 0.58 0.94 1.78 0.13 W 320 kHz efficiency Vout = 0.6 V Vout = 1.0 V Vout = 1.8 V Vout = 3.3 V CTRL deasserted idle power typ switching frequency FAULT PROTECTION parameter conditions/description min output over voltage protection output over current protection input under voltage protection adjustable via PMBus commands input over voltage protection adjustable via PMBus commands over temperature protection (OTP) measured on the module thermal protection hysteresis difference between temperature fault and warning typ max units (OVP) adjustable via PMBus commands 5.6 V (OCP) adjustable via PMBus commands TBD A 4.5 14 V 125 °C 15 °C POWER CONNECTIONS symbol pin IO type VIN 1A Power Input voltage GND 2A Ground Power ground VOUT 3A Power Output voltage description COMMUNICATION CONNECTIONS symbol pin IO type description +S 4A Analog Output voltage positive sense input -S 4B Analog Output voltage negative sense input VSET 5A Digital Output voltage pin-strap VTRK 5B Analog Voltage tracking input SALRT 6A Digital SMBus alert SDA 6B Digital SMBus data SCL 7A Digital SBMBus clock SYNC 7B Digital Synchronization I/O SA0 8A Digital SMBus Address pinstrap CTRL 8B Digital Remote control or enable pin DDC 9A Digital Digital-DC Communications bus (equivalent to Ericsson Power GCB) PREF 9B Ground Pin-strap ground cui.com V For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 4 of 13 LOGIC INPUT/OUTPUT CHARACTERISTICS parameter conditions/description min input high voltage (VIH) CTRL, DDC, SA0, SCL, SDA, SYNC, VSET input low voltage (VIL) CTRL, DDC, SA0, SCL, SDA, SYNC, VSET output high voltage (VOH) DDC, SALRT, SDA, SYNC output low voltage (VOL) DDC, SALRT, SDA, SYNC typ max 2 units V 0.8 2.25 V V 0.4 V max units 15,000 µF OUTPUT DECOUPLING CAPACITOR RECOMMENDATION parameter conditions/description min COUT total output capacitance located on host board 300 typ DDC CONFIGURATION REQUIREMENTS A pull-up resistor is required on the DDC in order to guarantee the rise time as follows: Rise TimeDDC = RDDC * CDDC < 1 µs RDDC is the DDC pull-up resistor and CDDC is the DDC capacitive loading. The pull-up resistor should be tied to an external 3.3V or 5V supply. The designer needs to ensure that the resistor pull-up voltage is present during module power-up. Each module connected to the DDC presents ~10 pF, each inch of FR4 PCB trace introduces ~2 pF of capacitive loading. SMBUS CONFIGURATION REQUIREMENTS The complete specifications for the SMBus can be found on the following web pages: www.pmbus.info , smbus.org TYPICAL CHARACTERISTICS Conditions (applies to all graphs unless stated otherwise): TP1 = 25°C, Vin = 12 V, Cin = 470 μF/10 mΩ, Cout = 470 μF/8 mΩ, Iout = Imax cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER TYPICAL CHARACTERISTICS (CONTINUED) Conditions (applies to all graphs unless stated otherwise): Start-up Shut-down (Vout = 1.0 V) (Vout = 1.0 V) Output Load Transient Response (Vout = 1.0 V, Iout = 3.0 TP1 = 25°C, Vin = 12 V, Cin = 470 μF/10 mΩ, Cout = 470 μF/8 mΩ, Iout = Imax 9.0 3.0 A, 2 A/μs) Output Ripple and Noise (Vout = 1.0 V) cui.com date 11/07/2014 │ page 5 of 13 For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 6 of 13 MECHANICAL DRAWING units: mm [inches] tolerance unless specified: X.X ±0.50 [0.02] X.XX ±0.25 [0.01] (not applied on footprint or typical values) cui.com PIN NUMBER PIN NAME 1A VIN 2A GND 3A VOUT 4A +S 4B -S 5A VSET 5B VTRK 6A SALRT 6B SDA 7A SCL 7B SYNC 8A SA0 8B CTRL 9A DDC 9B PREF MATERIAL PLATING Au 0.1 μm over Ni 1~3 μm Copper Alloy Au 0.76 μm For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER OPERATING INFORMATION POWER CONVERSION AND MANAGEMENT The NDM2Z-12 modules are available in different configurations; not all pins and functions are supported by each configuration. This document describes all pins and functions. The Novum Z Products PMBus Commands application note defines the available PMBus™ commands. REQUIRED CONFIGURATIONS NDM2Z-12 Module Pins Each NDM2Z-12 module should have a resistor placed between VSET and PREF to set the output voltage of the module. The maximum output voltage which can be configured by PMBus commands can never exceed 110% of the voltage set by the VSET pin. The SMBus address of each module is set by either pin-strap configuration or resistor value associated with the SA0 pin. More information regarding setting the SMBus address for a module can be found in the section titled “SMBus”. PCB Layout Good performance of any point of load voltage regulator module can only be achieved with careful PCB layout considerations. Ground planes or very wide traces should be used for power and ground routing. Input capacitors should be placed close to the input voltage pins of the module and output capacitors should be placed close to the load. The module should also be placed as close as possible to the load. INPUT AND OUTPUT CAPACITORS Input Capacitors Input capacitors are recommended to be used with the NDM2Z-12 module in order to minimize input voltage ripple. A 330 μF POSCAP or electrolytic and 3x 22 μF ceramic capacitors should be placed as close as possible to the input pins of the module. Additional input capacitors may be used if less input voltage ripple is desired. Output Capacitors Output capacitors are recommended to be used with the NDM2Z-12 module in order to improve transient response and minimize output voltage ripple. A 330 μF POSCAP or electrolytic and 3x 22 μF ceramic capacitors should be placed as close as possible to the load. Additional output capacitors may be used to further improve the output voltage characteristics. date 11/07/2014 │ page 7 of 13 Power Conversion Overview The NDM2Z-12 module has several features to enable high power conversion efficiency. Non-linear loop response (NLR) improves the response time and reduces the output deviation as a result of load transients. The incorporation of DFM enhances the performance of CUI modules over that available from conventional analog POL offerings. Power Management Overview The NDM2Z-12 module incorporates a wide range of power management features. All power management functions can be configured via the SMBus interface. The NDM2Z-12 can monitor and report many characteristics of the module including input voltage, output voltage, output current and internal temperature. Additionally, the NDM2Z-12 includes circuit protection features that protect the module and load from damage due to system faults. Monitoring parameters can also be configured to provide alerts for specific conditions. The ability of CUI modules to digitally control, configure and monitor OS features provides significant benefits over traditional analog POL products. CONFIGURING THE MODULE Pin Settings Pin SA0 is used to set the SMBus address of the NDM2Z-12 module. Details of this feature are discussed in the section titled “SMBus”. Pin SYNC is used to synchronize the switching clock of the module to an external clock source. More information regarding synchronization can be found in the section titled “SWITCHING FREQUENCY AND SYNCHRONIZATION”. Pin VSET is used to configure the output voltage of the module. The voltage established by the VSET pin limits the maximum output voltage that can be configured by SMBus commands. The SA0, SYNC and VSET pin configurations are read by the module when power is applied or whenever a SMBus RESTORE command is issued. The CTRL pin is active high and can be used to enable the module. Internal connections on the module will drive the CTRL pin high if it is left floating. Pins +S and -S are used for remote voltage sensing of the output voltage. cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 8 of 13 Unused Pins Table 1 describes the required or allowed connections for unused pins on the NDM2Z-12 module. Table 1: Unused Pins VSET Tie to PREF with 133 kΩ resistor, see VOUT_COMMAND PMBus command VTRK, SA0, SYNC, CTRL, +S, -S Float DDC, SCL, SDA, SALRT Pulled high with resistor, see "RECOMMENDED OPERATIN CONDITIONS" Configuration of Parameters Using the SMBus The NDM2Z-12 module is supplied with default settings. All module settings (except for module SMBus address, configured by pin SA0) can be re-configured via the SMBus interface. The output voltage can not be set to greater than 110% of the voltage set by the VSET pin. START-UP PROCEDURE Start-up Sequence The NDM2Z-12 module follows an internal start-up procedure after power is applied to pin VIN. Table 2 describes the start-up sequence. If the module is to be synchronized to an external clock source, the clock frequency must be stable prior to asserting CTRL (or applying input voltage to the module if CTRL is not used). Once this process is completed, the module is ready to accept assertion of CTRL and commands via the SMBus interface. Table 2: NDM2Z-12 Start-up sequence STEP STEP NAME DESCRIPTION TIME DURATION 1 Power applied or RESTORE_FACTORY Input voltage is applied to NDM2Z-12 module pin VIN or RESTORE_FACTORY PMBus command issued Depends on input supply ramp time 2 Factory configuration settings Module loads factory configuration settings. This step is also performed after using PMBus commands to restore the factory configuration file. 3 SA0, SYNC and VSET pin settings Module loads values configured by the SA0, SYNC and VSET pins. 4 Default configuration settings Module loads default configuration settings. This data over-rides pin setting data, except for maximum limit for VOUT_COMMAND. This step also performed after using PMBus commands to restore the default configuration file. 5 User configuration settings Module loads user configuration settings. This data over-rides pin setting and default configuration data, except for maximum limit for VOUT_COMMAND. This step also performed after using PMBus commands to restore the user configuration file. 6 Module ready The module is ready to accept a CTRL signal. --- 7 Pre-ramp delay The module requires approximately 5 ms following a CTRL signal and prior to ramping its output. Additional pre-ramp delay may be configured using PMBus commands. Approximately 5 ms Soft-start Delay Ramp Times Once CTRL is asserted the NDM2Z-12 module requires a pre-ramp delay time before the output voltage may be allowed to start the ramp-up process. After the delay period has expired, the output will begin to ramp towards the target voltage according to the pre-configured soft-start ramp time that has been set. It is recommended to set the soft-start ramp time to a value greater than 500 μs in order to prevent fault conditions due to excessive inrush current. Soft start delay and ramp times may be set using PMBus commands. Output Pre-Bias An output pre-bias condition exists when a non-zero Approximately 10 ms (module will ignore a CTRL signal and PMBus commands during this period) voltage is present on the NDM2Z-12 module output before the module output voltage is enabled. If a pre-bias voltage exists, the output voltage of the module is set to match the existing pre-bias voltage. The output voltage is then ramped to the final regulation value in the specified ramp time. The pre-bias voltage can be higher or lower than the final output voltage. Higher pre-bias output voltages will cause energy to be pumped into the input voltage rail powering the module. This condition could cause the module to report an error condition if the input voltage exceeds the input over voltage lock out threshold. The module will report an error condition if the pre-bias output voltage exceeds the output over voltage protection threshold. cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER Soft-stop Delay and Ramp Times After CTRL is de-asserted the NDM2Z-12 module utilizes a pre-ramp delay time before the output starts the rampdown process. After the delay period has expired, the output will begin to ramp towards ground according to the pre-configured soft-stop ramp time that has been set. It is recommended to set the soft-start ramp down to a value greater than 500 μs in order to prevent voltage spikes in the module input supply rail due the energy stored in the output capacitors. There will be a delay after the output voltage has reached ground potential and then the output of the module will be set to high impedance. Once the output of the module is high impedance the output voltage may float to a non-zero value if another source or leakage path is connected to the output. The soft-stop delay and ramp times may be configured via PMBus commands. PMBus commands can be used to set the output of the NDM2Z-12 module to high impedance as soon as the output voltage drops below a selectable threshold. OUTPUT VOLTAGE SETTING Pin-Strap and Resistor Setting Methods Using the pin-strap method, the voltage on the VOUT pin of the NDM2Z-12 module can be set to one of three default voltages as shown in Table 3. Table 4 lists the available output voltage settings with a resistor connected between VSET and PREF. Table 3: Pin-strap VOUT voltage settings VSET VOUT (V) LOW (< 0.8 V) 0.6 OPEN (N/C) 1.2 HIGH (> 2.0 V) 2.5 date 11/07/2014 │ page 9 of 13 Table 4: Resistor VOUT voltage settings RESISTOR (kΩ) VOUT (V) RESISTOR (kΩ) VOUT (V) 10.0 0.60 46.4 1.50 11.0 0.65 51.1 1.60 12.1 0.70 56.2 1.70 13.3 0.75 61.9 1.80 14.7 0.80 68.1 1.90 16.2 0.85 75.0 2.00 17.8 0.90 82.5 2.10 19.6 0.95 90.9 2.20 21.5 1.00 100.0 2.30 23.7 1.05 110.0 2.50 26.1 1.10 121.0 3.00 28.7 1.15 133.0 3.30 31.6 1.20 147.0 4.00 34.8 1.25 162.0 5.00 38.3 1.30 178.0 5.50 42.2 1.40 SMBus Setting Method The voltage present at the VOUT pin of the NDM2Z-12 module can be reconfigured using PMBus commands. A voltage level reconfigured by a PMBus command overrides the voltage set by the VSET pin, but cannot be set to greater than 110% of the voltage set by the VSET pin. Voltage Tracking The NDM2Z-12 module includes a feature that allows the output ramp voltage to track the ramp of a reference voltage which is applied to the VTRK pin. The voltage ramp tracking capability can be configured so that member modules track at either 50% or 100% of the reference voltage ramp rate. In addition, a member module can be configured so that the termination voltage either tracks or ignores perturbations on the reference voltage once it has stabilized. Tracking at 50% and tracking final voltage perturbations is intended for DDR memory applications. All other applications which required voltage tracking should use 100% tracking and ignore final voltage perturbations. The reference voltage for tracking must have a target voltage which is equal to or greater than the target voltage of the member modules. The turn-on delay of the reference voltage must be at least 10 ms greater than that set for the member modules. In voltage tracking mode, the turn-off delay of the member modules establishes the time duration which the member modules will track the reference voltage after CTRL is de-asserted. The turn-off delay of the member modules must be at least 5 ms greater than the sum of the turn-off delay and fall time of the reference voltage. cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER Current sharing modules which are also configured to track a voltage must have all of the VTRK pins tied together. All of the CTRL pins of the member modules must also be connected together and driven by a common source. The rise and fall times of the member modules should be set between 5 ms and 10 ms to ensure current sharing while ramping. PMBus commands can be used to configure the voltage tracking features. Voltage Margining The NDM2Z-12 module offers a means to vary the output voltage higher or lower relative to the nominal voltage setting. The rate of change of the output voltage during voltage margining is also configurable. The margin feature can be reconfigured through PMBus commands. SWITCHING FREQUENCY AND SYNCHRONIZATION Switching Frequency The switching frequency of the NDM2Z-12 module can be reconfigured by PMBus commands or controlled by an external clock source connected to the SYNC pin. If the module is operated at a switching frequency of other than the factory default setting, the compensation may need to be adjusted and the ripple, noise, transient response and efficiency may be affected. SYNC Auto Detect The NDM2Z-12 module will automatically check for a clock signal on the SYNC pin after CTRL is asserted (or applying input voltage to the module if CTRL is not used). If a clock signal is present, the module will synchronize to the rising edge of the external clock. The external clock signal must be stable and conform to the “RECOMMENDED OPERATING CONDITIONS” parameters when CTRL is asserted (or applying input voltage to the module if CTRL is not used). In the event of a loss of the external clock signal, the output voltage of the module may show transient overshoot or undershoot and the module will automatically configure to switch at a frequency close to the previous incoming frequency. If no incoming clock signal is present when CTRL is asserted (or applying input voltage to the module if CTRL is not used), the module will switch at the frequency set by the configuration file. date 11/07/2014 │ page 10 of 13 loop every time the output voltage ramps to the regulated level. PMBus commands can be used to configure when the module re-compensates the loop. The user also has the option to manually configure the loop compensation. Non-Linear Response (NLR) Settings The NDM2Z-12 module incorporates a non-linear response (NLR) loop that decreases the response time and the output voltage deviation in the event of a sudden output load current step. This implementation results in a higher equivalent loop bandwidth than what would be possible using a traditional linear loop. PMBus commands can be used to configure the NLR response of the module. Adaptive Diode Emulation Please contact CUI technical support regarding the implementation of adaptive diode emulation. Adaptive Frequency Control The NDM2Z-12 module includes adaptive frequency control to improve conversion efficiency. Adaptive frequency control is not available for current sharing groups and is not allowed when the module is placed in auto-detect mode and a clock source is present on the SYNC pin. Adaptive frequency control is only available while the module is operating within adaptive diode emulation mode. Adaptive frequency control can be enabled and disabled with PMBus commands. MULTI-MODULE CONFIGURATION Output Sequencing Multiple device sequencing of NDM2Z-12 modules may be achieved by issuing PMBus commands to assign the preceding device in the sequencing chain as well as the device that will follow in the sequencing chain. The CTRL pins of all devices in a sequencing group must be tied together and driven high to initiate a sequenced turn-on of the group. CTRL must be driven low to initiate a sequenced turnoff of the group. CONTROL LOOP Adaptive Loop Compensation The NDM2Z-12 module employs automatic adaptive loop compensation to increase the performance and stability of the module over a wide range of conditions. The default setting configures the module to re-compensate the control cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER Fault Spreading NDM2Z-12 modules can be configured to broadcast a fault event over the GCB (Group Communication Bus) to the other modules in the group. When a nondestructive fault occurs and the module is configured to shut down on a fault, the module will shut down and broadcast the fault event over the GCB. The other modules on the GCB will shut down together if configured to do so, and will attempt to re-start in their prescribed order if configured to do so. PMBus commands can be used to configure the transmission and reception of faults. Phase Spreading When multiple NDM2Z-12 modules share a common DC input supply, it may be desirable to adjust the clock phase offset of each module. In order to enable phase spreading, all modules must be synchronized to the same switching clock. For modules driven by a common synchronizing clock the phase offset of each module is controlled by the module addresses; phase offset = device address x 45°. For example: • A module address of 0x00 or 0x20 would configure 0° of phase offset • A module address of 0x01 or 0x21 would configure 45° of phase offset • A module address of 0x02 or 0x22 would configure 90° of phase offset The phase offset of each module may also be set via the PMBus. POWER FAULT MANAGEMENT Input Under and Over Voltage Lockout Input under voltage lockout (UVLO) and input over voltage lockout (OVLO) indicate faults for the NDM2Z-12 module when the input voltage falls outside of preset thresholds. The default response due to an input voltage fault is an immediate shutdown of the module. The module will continuously check for the presence of the fault condition. Once the fault condition is no longer present, the module will be re-enabled. PMBus commands can be used to configure the thresholds and response of the module to the fault condition. Output Under and Over Voltage Protection The NDM2Z-12 module employs an output voltage protection circuit that can be used to protect load circuitry from being subjected to voltages outside of prescribed limits. A hardware comparator is used to compare the voltage seen at the +S pin to voltage thresholds. The default response to an output voltage fault is to immediately shut down. The module will continuously check date 11/07/2014 │ page 11 of 13 for the presence of the fault condition, when the fault condition no longer exists the module will be re-enabled. PMBus commands can be used to set the voltage thresholds and configure the response of the module to the fault condition. When operating from an external clock the only allowed response to an output voltage fault is an immediate shutdown. Output Over Current Protection Output over current protection will protect the NDM2Z-12 module and load from damage if an overload condition is imposed on the output. The module will indicate a fault condition when the output current limit threshold is exceeded. The default response from an output current fault is an immediate shutdown of the module. The module will continuously check for the presence of the fault condition, and if the fault condition no longer exists the module will be re-enabled. PMBus commands can be used to configure the current limit threshold and the response of the module to the fault condition. Thermal Overload Protection The NDM2Z-12 module includes a thermal sensor that measures the temperature of the module and indicates a fault when the temperature exceeds a preset limit. The default response from a temperature fault is an immediate shutdown of the module. The module will continuously check for the fault condition and once the fault has cleared the module will be re-enabled. PMBus commands can be used to configure the thermal protection threshold and the response of the module to the fault condition. Permanent damage to the module may result if the thermal limit is set too high. SMBUS SMBus Communications The NDM2Z-12 module provides a SMBus interface that enables the user to configure the module operation as well as monitor input and output parameters. The module can be used with any standard 2-wire I2C host device, accepts most standard PMBus commands, is compatible with SMBus version 2.0 and includes an SALRT line to help mitigate bandwidth limitations related to continuous fault monitoring. It is recommended that CTRL be pulled low while configuring the module with PMBus commands. Pull-up resistors are required on the SMBus lines as described in "RECOMMENDED OPERATING CONDITIONS". cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER SMBus Addresses When communicating with multiple SMBus devices using the SMBus interface, each device must have a unique address so the host can distinguish between the devices. The NDM2Z-12 module address can be set according to the pin-strap options listed in Table 5; address values are right-justified. If additional module addresses are required, a resistor can be connected to pin SA0 as shown in Table 6 to provide up to 25 unique module addresses. Table 5: Pin-strap SMBus Addressing SA0 ADDRESS HIGH 0x25 OPEN 0x24 LOW 0x23 Table 6: Single Resistor SMBus Addressing RSA0 (kΩ) ADDRESS RSA0 (kΩ) ADDRESS 10.0 0x64 34.8 0x71 11.0 0x65 38.3 0x72 12.1 0x66 42.2 0x73 13.3 0x67 46.4 0x74 14.7 0x68 51.1 0x75 16.2 0x69 56.2 0x76 17.8 0x6A 61.9 0x77 19.6 0x6B 68.1 0x78 21.5 0x6C 75.0 0x79 23.7 0x6D 82.5 0x7A 26.1 0x6E 90.9 0x7B 28.7 0x6F 100.0 0x7C 31.6 0x70 Monitoring Via SMBus A system controller can be used to monitor the NDM2Z-12 module system parameters through the SMBus. Fault conditions can be detected by monitoring the SALRT pin, which will be asserted when pre-configured fault conditions occur. Modules can also be monitored for power conversion parameters including but not limited to the following: • • • • • • Input voltage Output voltage Output current Module temperature Switching frequency Duty cycle date 11/07/2014 │ page 12 of 13 SINGLE WIRE COMMUNICATIONS Digital-DC Bus The DDC (Digital-DC Communication Bus) is used to communicate between NDMxZ modules. This dedicated bus provides the communication channel between modules for features such as sequencing, fault spreading, and current sharing. A pull-up resistor is required on the DDC as defined in “RECOMMENDED OPERATING CONDITIONS”. Snapshot™ Parameter Capture The NDM2Z-12 module offers features that enable the user to capture parametric data during normal operation or following a fault. The Snapshot feature enables the user to read status and parameter values via a block read transfer through the SMBus. This can be done during normal operation, although it should be noted that reading the 22 bytes will occupy the SMBus for up to 1400 μs. The SNAPSHOT_CONTROL command enables the user to store the snapshot parameters to flash memory in response to a pending fault as well as to read the stored data from flash memory after a fault has occurred. Automatic writes to flash memory following a fault are triggered when any fault threshold level is exceeded, provided that the specific response to that fault is to shut down (writing to flash memory is not allowed if the module is configured to re-try following the specific fault condition). It should also be noted that the input voltage to the module must be maintained during the time when the module is writing the data to flash memory; a process that requires between 700 μs to 1400 μs depending on whether the data is set up for a block write. Undesirable results may be observed if the input voltage to the module drops too low during this process. In the event that the module experiences a fault and power is lost, the user can extract the last SNAPSHOT parameters stored during the fault by using the SMBus to transfer data from flash memory to RAM and then using the SMBus to read data from RAM. THERMAL CONSIDERATIONS Mounting Heat from the NDM2Z-12 module will be conducted through the pins to the host board. Provisions must be made for the host board to accommodate this additional heating. Airflow Airflow past the NDM2Z-12 module will assist in cooling the module. Factors affecting the efficiency of the cooling include the rate, direction and temperature of the airflow. cui.com For more information, please visit the product page. CUI Inc │ MODEL: NDM2Z-12V │ DESCRIPTION: AUTO COMPENSATED, DIGITAL DC-DC POL CONVERTER date 11/07/2014 │ page 13 of 13 REVISION HISTORY rev. date 0.9 03/14/2014 0.91 11/07/2014 The revision history provided is for informational purposes only and is believed to be accurate. Headquarters 20050 SW 112th Ave. Tualatin, OR 97062 800.275.4899 Fax 503.612.2383 cui.com [email protected] Novum is a trademark of CUI. PMBus is a trademark of SMIF, Inc. Digital-DC is a trademark of Intersil Corporation. CUI Novum products use patented technology licensed from Power-One. All other trademarks are the property of their respective owners. CUI offers a two (2) year limited warranty. Complete warranty information is listed on our website. CUI reserves the right to make changes to the product at any time without notice. Information provided by CUI is believed to be accurate and reliable. However, no responsibility is assumed by CUI for its use, nor for any infringements of patents or other rights of third parties which may result from its use. CUI products are not authorized or warranted for use as critical components in equipment that requires an extremely high level of reliability. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.