OKDX-T/25-W12-001-C

OKDx-T/25-W12-xxx-C www.murata-ps.com 25A Digital PoL DC-DC Converter Series Typical units FEATURES PRODUCT OVERVIEW  Small package: 25.65 x 13.8 x 8.2 mm (1.01 x 0.543 x 0.323 in) SIP: 26.3 x 7.6 x 15.6 mm (1.035 x 0.30 x 0.614 in) The OKDx-T/25-W12 series are high efficiency, digital point-of-Load (PoL) DC-DC power converters capable of delivering 25A/82.5W. Available in three different package formats, through-hole, single-inline, and surface mount, these converters have a typical efficiency of 97.1%. PMBus™ compatibility allows monitoring and configuration of critical system-level performance requirements. Apart from  0.6 V - 3.3 V output voltage range  High efficiency, typ. 97.1% at 5Vin, 3.3Vout half load  Configuration and Monitoring via PMBus™  Adaptive compensation of PWM control loop & fast loop transient response standard PoL performance and safety features like OVP, OCP, OTP, and UVLO, these digital converters have advanced features: digital current sharing (full power, no derating), non-linear transient response, optimized dead time control, synchronization, and phase spreading. These converters are ideal for use in telecommunications, networking, and distributed power applications.  Synchonization & phase spreading  Current sharing, Voltage Tracking & Voltage margining  MTBF 20.2 Mh  Non-Linear Response for reduction of decoupling capacitor  Remote control & power good  Output short-circuit, output over voltage, & over temperature protection  Certified to UL/IEC 60950-1 Power Management via PMBus™ Applications  Configurable soft-start/stop  Distributed power architectures  Configurable output voltage (Vout) and voltage margins (Margin low and Margin high)  Intermediate bus voltage applications  Configurable protection limits for OVP, input over voltage, input under voltage, over current, on/off, and temperature  Network equipment  Servers and storage applications  Status monitor Vout, Iout, Vin, Temp, Power good, and On/Off PART NUMBER STRUCTURE OKD x - T / 25 - W12 E - xxx - C Digital Non-isolated PoL Y = Surface Mount H = Horizontal Mount Through-Hole X = SIP Trimmable Output Voltage Range 0.6 - 3.3Vdc RoHS Hazardous Substance Compliance C = RoHS-6 (does not claim EU RoHS exemption 7b – lead in solder) Software Configuration Digits (001 is positive turn-on logic) (002 is negative turn-on logic)* Long pin length (5.5mm) Maximum Rated Output Current in Amps Input Voltage Range 4.5-14Vdc *Special quantity order is required; contact Murata Power Solutions for MOQ and lead times. PM www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 1 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series ORDERING GUIDE Model Number OKDY-T/25-W12-001-C OKDH-T/25-W12-001-C OKDX-T/25-W12-001-C OKDX-T/25-W12E-001-C Output 0.6-3.3 V, 25 A/ 82.5 W Absolute Maximum Ratings Characteristics Operating temperature (see Thermal Consideration section) TP1, TP2 TS Storage temperature VI Input voltage (See Operating Information Section for input and output voltage relations) Logic I/O voltage CTRL, SA0, SA1, SALERT, SCL, SDA, VSET, SYNC, GCB, PG Ground voltage differential -S, PREF, GND Analog pin voltage VO, +S, VTRK General and Safety Safety Calculated MTBF Min -40 -40 -0.3 -0.3 -0.3 -0.3 Conditions Designed for UL/IEC/EN 60950 1 Telcordia SR-332, Issue 2 Method 1 Stress in excess of Absolute Maximum Ratings may cause permanent damage. Absolute Maximum Ratings, sometimes referred to as no destruction limits, are normally tested with one parameter at a time exceeding the limits in the Electrical Specification. If exposed to stress above these limits, function and performance may degrade in an unspecified manner. Configuration File This product is designed with a digital control circuit. The control circuit uses a configuration file which determines the functionality and performance of the product. The Electrical Specification table shows parameter values of func- Min Typ Typ 20.2 Max 125 125 16 6.5 0.3 6.5 Max Unit °C °C V V V V Unit Mhrs tionality and performance with the default configuration file, unless otherwise specified. The default configuration file is designed to fit most application needs with focus on high efficiency. If different characteristics are required it is possible to change the configuration file to optimize certain performance characteristics. Note that current sharing operation requires changed configuration file. In this Technical specification examples are included to show the possibilities with digital control. See Operating Information section for information about trade offs when optimizing certain key performance characteristics. VIN VOUT CI CO GND +Sense -Sense (PGOOD) (SA1) SALERT CTRL VSET Controller and digital interface SYNC SCL SDA SA0 GCB VTRK PREF Fundamental Circuit Diagram www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 2 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Electrical Specifications, OKDY-T/25-W12-xxx-C and OKDH-T/25-W12-xxx-C TP1 = -30 to +95°C, VIN = 4.5 to 14 V, VIN > VOUT + 1.0 V Typical values given at: TP1 = +25 °C, VIN = 12.0 V, max IOUT, unless otherwise specified under Conditions. Default configuration file, 190 10-CDA 102 0206/001. External CIN = 470 μF/10 mΩ, COUT = 470 μF/10 mΩ. See Operating Information section for selection of capacitor types. Sense pins are connected to the output pins. Characteristics VI Input voltage rise time Conditions monotonic Output voltage without pin strap Output voltage adjustment range Output voltage adjustment including margining Output voltage set-point resolution VO Load regulation; IO = 0 - 100% VOac Output ripple & noise CO = 470 μF (minimum external capacitance). See Note 11 IO Output current IS Static input current at max IO Ilim Current limit threshold Isc Short circuit current RMS, hiccup mode, See Note 3 Efficiency max IO Pd Power dissipation at max IO Pli Input idling power (no load) Default configuration: Continues Conduction Mode, CCM PCTRL Input standby power Turned off with CTRL-pin Ci Internal input capacitance Max 2.4 Unit V/ms 3.3 3.63 V V V % Vo 1 % 2 % ±0.025 -1 -2 47 2 2 2 3 2 2 2 3 20 30 40 60 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V See Note 18 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 0.001 Ω mV mV mVp-p 25 1.58 2.43 4.13 7.32 27 50% of max IO
See Note 17 0.60 0.54 Internal resistance +S/-S to VOUT/GND Line regulation Typ 1.2 Including line, load, temp. See Note 14 Current sharing operation See Note 15 Output voltage accuracy Min A 37.5 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 8 6 5 4 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 84.4 89.4 93.1 95.2 79.2 85.7 90.8 93.9 3.93 4.17 4.55 5.34 0.56 0.57 0.67 0.92 Default configuration: Monitoring enabled, Precise timing enabled 170 70 A A A % % W W mW μF www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 3 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Characteristics Co Internal output capacitance Total external output capacitance COUT ESR range of capacitors (per single capacitor) Vtr1 ttr1 fs Load transient peak voltage deviation (H to L) Load step 25-75-25% of max IO Default configuration di/dt = 2 A/μs CO = 470 μF (minimum external capacitance) see Note 12 Load transient recovery time, Note 5 (H to L) Load step 25-75-25% of max IO Default configuration di/dt = 2 A/μs CO = 470 μF (minimum external capacitance) see Note 12 Switching frequency Switching frequency range Switching frequency set-point accuracy Control Circuit PWM Duty Cycle Minimum Sync Pulse Width Input Clock Frequency Drift Tolerance Input Under Voltage Lockout, UVLO Input Over Voltage Protection, IOVP Power Good, PG, See Note 2 Output voltage Over/Under Voltage Protection, OVP/UVP Over Current Protection, OCP UVLO threshold UVLO threshold range Set point accuracy UVLO hysteresis UVLO hysteresis range Delay Fault response IOVP threshold IOVP threshold range Set point accuracy IOVP hysteresis IOVP hysteresis range Delay Fault response PG threshold PG hysteresis PG delay PG delay range UVP threshold UVP threshold range UVP hysteresis OVP threshold OVP threshold range UVP/OVP response time UVP/OVP response time range Fault response OCP threshold OCP threshold range Protection delay, Protection delay range Fault response Conditions Min Typ 200 See Note 9 300 15 000 Unit μF μF See Note 9 5 30 mΩ VO = 0.6 V 95 VO = 1.0 V 105 VO = 1.8 V 115 VO = 3.3 V 168 VO = 0.6 V 74 VO = 1.0 V 85 VO = 1.8 V 122 VO = 3.3 V 140 mV μs 320 200-640 PMBus configurable External clock source -5 5 150 -13 5 95 13 3.85 3.85-14 PMBus configurable -150 150 0.35 0-10.15 2.5 Automatic restart, 70 ms 16 4.2-16 PMBus configurable See Note 3 PMBus configurable -150 PMBus configurable See Note 3 See Note 19 PMBus configurable PMBus configurable PMBus configurable PMBus configurable See Note 3 PMBus configurable See Note 4 PMBus configurable See Note 3 Max 150 1 0-11.8 2.5 Automatic restart, 70 ms 90 5 Direct after DLC 0-500 85 0-100 5 115 100-115 25 kHz kHz % % ns % V V mV V V μs V V mV V V μs % VO % VO s % VO % VO % VO % VO % VO μs 5-60 μs Automatic restart, 70 ms 32 0-32 32 1-32 Automatic restart, 70 ms A A Tsw Tsw www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 4 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Characteristics Over Temperature Protection, OTP at P2 See Note 8 VIL VIH IIL VOL VOH IOL IOH tset thold tfree Cp Conditions OTP threshold OTP threshold range OTP hysteresis OTP hysteresis range Fault response Logic input low threshold Logic input high threshold Logic input low sink current Logic output low signal level Logic output high signal level Logic output low sink current Logic output high source current Setup time, SMBus Hold time, SMBus Bus free time, SMBus Internal capacitance on logic pins Initialization time Output Voltage Delay Time See Note 6 Output Voltage Ramp Time See Note 13 Delay duration Delay duration range Delay accuracy turn-on Delay accuracy turn-off Ramp duration Ramp duration range Ramp time accuracy VTRK Input Bias Current VTRK Tracking Ramp Accuracy (VO - VVTRK) VTRK Regulation Accuracy (VO - VVTRK) Current difference between products in a current sharing group Min PMBus configurable PMBus configurable See Note 3 SYNC, SA0, SA1, SCL, SDA, GCB, CTRL, VSET CTRL SYNC, SCL, SDA, SALERT, GCB, PG See Note 1 See Note 1 See Note 1 READ_IOUT vs IO 0.8 V V mA V V mA mA ns ns ms pF 2 0.6 0.4 2.25 4 2 10 See Note 10 See Note 16 PMBus configurable 40 10 5-500000 Current sharing operation VVTRK = 5.5 V 100% tracking, see Note 7 Current sharing operation 2 phases, 100% tracking VO = 1.0 V, 10 ms ramp 100% Tracking Current sharing operation 100% Tracking Steady state operation Ramp-up IO = 0-25 A, TP1 = 0 to +95 °C VI = 4.5-14 V, VO = 1.0 V IO = 0-25 A, TP1 = 0 to +95 °C VI = 4.5-14 V, VO = 0.6-3.3 V Note 1: See section I2C/SMBus Setup and Hold Times – Definitions. Note 2: Monitorable over PMBus Interface. Note 3: Automatic restart ~70 or 240 ms after fault if the fault is no longer present. Continuous restart attempts if the fault reappear after restart. See Operating Information and AN302 for other fault response options. Note 4: Tsw is the switching period. Note 5: Within +/-3% of VO Note 6: See section Soft-start Power Up. Note 7: Tracking functionality is designed to follow a VTRK signal with slew rate < 2.4 V/ms. For faster VTRK signals accuracy will depend on the regulator bandwidth. Note 8: See section Over Temperature Protection (OTP). Note 9: See section External Capacitors. ms ms -0.25/+4 ms -0.25/+4 ms 10 0-200 100 20 PMBus configurable READ_VIN vs VI READ_VOUT vs VO READ_IOUT vs IO Unit C C C C 300 250 2 Number of products in a current sharing group Monitoring accuracy Typ Max 120 -40…+125 25 0-165 Automatic restart, 240 ms 110 -100 ms μs % 200 100 ±100 μA mV mV -1 1 % -2 2 % Max 2 x READ_IOUT monitoring accuracy 2 7 A 3 1 % % ±1.7 A ±3.0 A Note 10: See section Initialization Procedure. Note 11: See graph Output Ripple vs External Capacitance and Operating information section Output Ripple and Noise. Note 12: See graph Load Transient vs. External Capacitance and Operating information section External Capacitors. Note 13: Time for reaching 100% of nominal Vout. Note 14: For Vout < 1.0 V accuracy is +/-10 mV. For further deviations see section Output Voltage Adjust using PMBus™. Note 15: Accuracy here means deviation from ideal output voltage level given by configured droop and actual load. Includes line, load and temperature variations. Note 16: For current sharing the Output Voltage Delay Time must be reconfigured to minimum 15 ms. Note 17: For steady state operation above 1.05 x 3.3 V, please contact your local Murata sales representative. Note 18: A minimum load current is not required if Low Power mode is used (monitoring disabled). Note 19: See sections Dynamic Loop Compensation and Power Good. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 5 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Efficiency and Power Dissipation Efficiency vs. Output Current, VI = 5 V Power Dissipation vs. Output Current, VI = 5 V [%] [W] 100 6 95 5 4 90 0.6 V 1.0 V 85 80 0.6 V 3 1.0 V 1.8 V 2 1.8 V 3.3 V 1 3.3 V 75 0 0 5 10 15 20 25 [A] 0 5 10 15 20 25 [A] Efficiency vs. load current and output voltage: TP1 = +25 °C, VI = 5 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Dissipated power vs. load current and output voltage: TP1 = +25 °C, VI = 5 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Efficiency vs. Output Current, VI = 12 V Power Dissipation vs. Output Current, VI = 12 V [%] [W] 100 6 5 95 4 90 0.6 V 1.0 V 85 80 0.6 V 3 1.0 V 1.8 V 2 1.8 V 3.3 V 1 3.3 V 75 0 0 5 10 15 20 25 [A] 0 5 10 15 20 25 [A] Efficiency vs. load current and output voltage at TP1 = +25 °C, VI = 12 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Dissipated power vs. load current and output voltage: TP1 = +25 °C, VI = 12 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Efficiency vs. Output Current and Switching Frequency Power Dissipation vs. Output Current and Switching frequency [%] [W] 95 6 5 90 200 kHz 85 200 kHz 4 320 kHz 3 320 kHz 80 480 kHz 2 480 kHz 75 640 kHz 1 640 kHz 70 0 0 5 10 15 20 Efficiency vs. load current and switch frequency at TP1 = +25 °C, VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ. Default configuration except changed frequency 25 [A] 0 5 10 15 20 25 [A] Dissipated power vs. load current and switch frequency at TP1 = +25 °C, VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ. Default configuration except changed frequency www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 6 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Load Transient Load Transient vs. External Capacitance, VO = 1.0 V [mV] 400 Universal PID, No NLR DLC, No NLR 300 Universal PID, Default NLR 200 Load Transient vs. External Capacitance, VO = 3.3 V [mV] 400 Universal PID, No NLR DLC, No NLR 300 Universal PID, Default NLR 200 DLC, Default NLR DLC, Default NLR Universal PID, Opt. NLR 100 DLC, Opt. NLR 0 0 1 2 3 4 Universal PID, Opt. NLR 100 DLC, Opt. NLR 0 0 5 [mF] 1 2 3 4 5 [mF] Load transient peak voltage deviation vs. external capacitance. Step (6.25-18.75-6.25 A). Parallel coupling of capacitors with 470 μF/10 mŸ, TP1 = +25 °C, VI = 12 V, VO = 1.0 V, fsw = 320 kHz, di/dt = 2 A/μs Load transient peak voltage deviation vs. external capacitance. Step (6.25-18.75-6.25 A). Parallel coupling of capacitors with 470 μF/10 mŸ, TP1 = +25 °C, VI = 12 V, VO = 3.3 V, fsw = 320 kHz, di/dt = 2 A/μs Load transient vs. Switch Frequency Output Load Transient Response, Default Configuration [mV] 400 Universal PID, No NLR DLC, No NLR 300 Universal PID, Default NLR 200 DLC, Default NLR Universal PID, Opt. NLR 100 DLC, Opt. NLR 0 200 300 400 500 600 [kHz] Load transient peak voltage deviation vs. frequency. Step-change (6.25-18.75-6.25 A). TP1 = +25 °C. VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ Output voltage response to load current Step-change (6.25-18.75-6.25 A) at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V di/dt = 2 A/μs, fsw = 320 kHz CO = 470 μF/10 mŸ Top trace: output voltage (200 mV/div.). Bottom trace: load current (5 A/div.). Time scale: (0.1 ms/div.). Note: For Universal PID, see section Dynamic Loop Compensation (DLC). www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 7 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Output Current Characteristic Output Current Derating, VO = 0.6 V Output Current Derating, VO = 1.0 V [A] [A] 30 30 3.0 m/s 25 3.0 m/s 25 2.0 m/s 20 2.0 m/s 20 1.0 m/s 15 1.0 m/s 15 0.5 m/s 10 0.5 m/s 10 Nat. Conv. 5 Nat. Conv. 5 0 0 60 70 80 90 100 110 120 [°C] 60 70 80 90 100 110 120 [°C] Available load current vs. ambient air temperature and airflow at VO = 0.6 V, VI = 12 V. See Thermal Consideration section. Available load current vs. ambient air temperature and airflow at VO = 1.0 V, VI = 12 V. See Thermal Consideration section. Output Current Derating, VO = 1.8 V Output Current Derating, VO = 3.3 V [A] [A] 30 30 3.0 m/s 3.0 m/s 25 25 2.0 m/s 2.0 m/s 20 20 1.0 m/s 1.0 m/s 15 15 0.5 m/s 0.5 m/s 10 10 Nat. Conv. 5 Nat. Conv. 5 0 0 50 60 70 80 90 100 110 50 120 [°C] Available load current vs. ambient air temperature and airflow at VO = 1.8 V, VI = 12 V. See Thermal Consideration section. 60 70 80 90 100 110 120 [°C] Available load current vs. ambient air temperature and airflow at VO = 3.3 V, VI = 12 V. See Thermal Consideration section. Current Limit Characteristics, VO = 1.0 V Current Limit Characteristics, VO = 3.3 V [V] [V] 1,2 4,0 1,0 3,0 0,8 4.5 V 0,6 5.0 V VI = 4.5 V VI = 5.0, 12, 14 V 0,4 4.5 V 5.0 V 2,0 12 V 12 V 14 V VI = 12, 14 V VI = 4.5, 5.0 V 14 V 1,0 0,2 0,0 0,0 25 27 29 31 33 35 [A] Output voltage vs. load current at TP1 = +25 °C, VO = 1.0 V. Note: Output enters hiccup mode at current limit. 25 27 29 31 33 35 [A] Output voltage vs. load current at TP1 = +25 °C, VO = 3.3 V. Note: Output enters hiccup mode at current limit. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 8 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Output Voltage Output Ripple & Noise, VO = 1.0 V Output Ripple & Noise, VO = 3.3 V Output voltage ripple at: TP1 = +25 °C, Trace: output voltage (20 mV/div.). Time scale: (2 μs/div.). VI = 12 V, CO = 470 μF/10 mŸ IO = 25 A Output voltage ripple at: TP1 = +25 °C, Trace: output voltage (20 mV/div.). Time scale: (2 μs/div.). VI = 12 V, CO = 470 μF/10 mŸ IO = 25 A Output Ripple vs. Input Voltage Output Ripple vs. Frequency [mVpk-pk] [mVpk-pk] 70 150 60 120 50 0.6 V 0.6 V 40 1.0 V 30 1.8 V 20 3.3 V 90 1.0 V 1.8 V 60 3.3 V 30 10 0 5 7 9 11 0 [V] 13 200 300 400 500 600 [kHz] Output voltage ripple Vpk-pk at: TP1 = +25 °C, CO = 470 μF/10 mŸ, IO = 25 A Output voltage ripple Vpk-pk at: TP1 = +25 °C, VI = 12 V, CO = 470 μF/10 mŸ, IO = 25 A. Default configuration except changed frequency. Output Ripple vs. External Capacitance Load regulation, VO = 1.0 V [mV] [V] 70 1,010 60 50 0.6V 40 1.0 V 30 1.8 V 20 3.3 V 1,005 4.5 V 5.0 V 1,000 12 V 14 V 0,995 10 0 0 1 2 3 4 5 [mF] Output voltage ripple Vpk-pk at: TP1 = +25 °C, VI = 12 V. IO = 25 A. Parallel coupling of capacitors with 470 μF/10 mŸ 0,990 0 5 10 15 20 25 [A] Load regulation at Vo = 1.0 V, TP1 = +25 °C, CO = 470 μF/10 mŸ www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 9 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Start-up and shut-down Start-up by input source Start-up enabled by connecting VI at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Shut-down by input source Top trace: output voltage (0.5 V/div.). Bottom trace: input voltage (5 V/div.). Time scale: (20 ms/div.). Start-up by CTRL signal Start-up by enabling CTRL signal at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Shut-down enabled by disconnecting VI at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Top trace: output voltage (0.5 V/div.). Bottom trace: input voltage (5 V/div.). Time scale: (2 ms/div.). Shut-down by CTRL signal Top trace: output voltage (0.5 V/div.). Bottom trace: CTRL signal (2 V/div.). Time scale: (20 ms/div.). Shut-down enabled by disconnecting VI at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Top trace: output voltage (0.5 V/div). Bottom trace: CTRL signal (2 V/div.). Time scale: (2 ms/div.). www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 10 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Electrical Specifications, OKDX-T/25-W12-xxx-C TP1 = -30 to +95 °C, VI = 4.5 to 14 V, VI > VO + 1.0 V Typical values given at: TP1 = +25 °C, VI = 12.0 V, max IO, unless otherwise specified under Conditions. Default configuration file, 190 10-CDA 102 0259/001. External CIN = 470 μF/10 mΩ, COUT = 470 μF/10 mΩ. See Operating Information section for selection of capacitor types. Sense pins are connected to the output pins. Characteristics VI Input voltage rise time Conditions monotonic Output voltage without pin strap Output voltage adjustment range Output voltage adjustment including margining Output voltage set-point resolution VO Load regulation; IO = 0 - 100% VOac Output ripple & noise CO = 470 μF (minimum external capacitance). See Note 11 IO Output current IS Static input current at max IO Ilim Current limit threshold Isc Unit V/ms 3.3 3.63 V V V % Vo See Note 17 -1 1 % -2 2 % 0.60 0.54 ±0.025 Short circuit current 47 2 2 2 3 2 2 2 3 20 30 40 60 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V See Note 18 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 0.001 RMS, hiccup mode, See Note 3 Efficiency max IO Pd Power dissipation at max IO Pli Input idling power (no load) Default configuration: Continues Conduction Mode, CCM PCTRL Input standby power Turned off with CTRL-pin Ci Internal input capacitance Ω mV mV mVp-p 25 1.61 2.46 4.17 7.35 27 50% of max IO
Max 2.4 Internal resistance +S/-S to VOUT/GND Line regulation Typ 1.2 Including line, load, temp. See Note 14 Current sharing operation See Note 15 Output voltage accuracy Min A 37.5 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 8 6 5 4 VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V VO = 0.6 V VO = 1.0 V VO = 1.8 V VO = 3.3 V 83.6 89.0 92.8 95.1 77.4 84.6 90.0 93.5 4.37 4.54 5.01 5.77 0.56 0.57 0.67 0.92 Default configuration: Monitoring enabled, Precise timing enabled 170 70 A A A % % W W mW μF www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 11 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Characteristics Co Internal output capacitance Total external output capacitance COUT ESR range of capacitors (per single capacitor) Vtr1 ttr1 fs Load transient peak voltage deviation (H to L) Load step 25-75-25% of max IO Default configuration di/dt = 2 A/μs CO = 470 μF (minimum external capacitance) see Note 12 Load transient recovery time, Note 5 (H to L) Load step 25-75-25% of max IO Default configuration di/dt = 2 A/μs CO = 470 μF (minimum external capacitance) see Note 12 Switching frequency Switching frequency range Switching frequency set-point accuracy Control Circuit PWM Duty Cycle Minimum Sync Pulse Width Input Clock Frequency Drift Tolerance Input Under Voltage Lockout, UVLO Input Over Voltage Protection, IOVP Power Good, PG, See Note 2 Output voltage Over/Under Voltage Protection, OVP/UVP Over Current Protection, OCP UVLO threshold UVLO threshold range Set point accuracy UVLO hysteresis UVLO hysteresis range Delay Fault response IOVP threshold IOVP threshold range Set point accuracy IOVP hysteresis IOVP hysteresis range Delay Fault response PG threshold PG hysteresis PG delay PG delay range UVP threshold UVP threshold range UVP hysteresis OVP threshold OVP threshold range UVP/OVP response time UVP/OVP response time range Fault response OCP threshold OCP threshold range Protection delay, Protection delay range Fault response Conditions Min Typ 200 See Note 9 300 15 000 Unit μF μF See Note 9 5 30 mΩ VO = 0.6 V 115 VO = 1.0 V 122 VO = 1.8 V 143 VO = 3.3 V 174 VO = 0.6 V 60 VO = 1.0 V 65 VO = 1.8 V 115 VO = 3.3 V 130 mV μs 320 200-640 PMBus configurable External clock source -5 5 150 -13 5 95 13 3.85 3.85-14 PMBus configurable -150 150 0.35 0-10.15 2.5 Automatic restart, 70 ms 16 4.2-16 PMBus configurable See Note 3 PMBus configurable -150 PMBus configurable See Note 3 See Note 19 PMBus configurable PMBus configurable PMBus configurable PMBus configurable See Note 3 PMBus configurable See Note 4 PMBus configurable See Note 3 Max 150 kHz kHz % % ns % V V mV V V μs V V mV V V μs 1 0-11.8 2.5 Automatic restart, 70 ms 90 5 Direct after DLC 0-500 85 0-100 5 115 100-115 25 % VO % VO ms s % VO % VO % VO % VO % VO μs 5-60 μs Automatic restart, 70 ms 32 0-32 32 1-32 Automatic restart, 70 ms A A Tsw Tsw www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 12 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Characteristics Over Temperature Protection, OTP at P2 See Note 8 VIL VIH IIL VOL VOH IOL IOH tset thold tfree Cp Conditions OTP threshold OTP threshold range OTP hysteresis OTP hysteresis range Fault response Logic input low threshold Logic input high threshold Logic input low sink current Logic output low signal level Logic output high signal level Logic output low sink current Logic output high source current Setup time, SMBus Hold time, SMBus Bus free time, SMBus Internal capacitance on logic pins Initialization time Output Voltage Delay Time See Note 6 Output Voltage Ramp Time See Note 13 Delay duration Delay duration range Delay accuracy turn-on Delay accuracy turn-off Ramp duration Ramp duration range Ramp time accuracy VTRK Input Bias Current VTRK Tracking Ramp Accuracy (VO - VVTRK) VTRK Regulation Accuracy (VO - VVTRK) Current difference between products in a current sharing group Min PMBus configurable PMBus configurable See Note 3 SYNC, SA0, SA1, SCL, SDA, GCB, CTRL, VSET CTRL SYNC, SCL, SDA, SALERT, GCB, PG See Note 1 See Note 1 See Note 1 READ_IOUT vs IO 0.8 V V mA V V mA mA ns ns ms pF 2 0.6 0.4 2.25 4 2 10 See Note 10 See Note 16 PMBus configurable 40 10 5-500000 Current sharing operation VVTRK = 5.5 V 100% tracking, see Note 7 Current sharing operation 2 phases, 100% tracking VO = 1.0 V, 10 ms ramp 100% Tracking Current sharing operation 100% Tracking Steady state operation Ramp-up IO = 0-25 A, TP1 = 0 to +95 °C VI = 4.5-14 V, VO = 1.0 V IO = 0-25 A, TP1 = 0 to +95 °C VI = 4.5-14 V, VO = 0.6-3.3 V Note 1: See section I2C/SMBus Setup and Hold Times – Definitions. Note 2: Monitorable over PMBus Interface. Note 3: Automatic restart ~70 or 240 ms after fault if the fault is no longer present. Continuous restart attempts if the fault reappear after restart. See Operating Information and AN302 for other fault response options. Note 4: Tsw is the switching period. Note 5: Within +/-3% of VO Note 6: See section Soft-start Power Up. Note 7: Tracking functionality is designed to follow a VTRK signal with slew rate < 2.4 V/ms. For faster VTRK signals accuracy will depend on the regulator bandwidth. Note 8: See section Over Temperature Protection (OTP). Note 9: See section External Capacitors. ms ms -0.25/+4 ms -0.25/+4 ms 10 0-200 100 20 PMBus configurable READ_VIN vs VI READ_VOUT vs VO READ_IOUT vs IO Unit C C C C 300 250 2 Number of products in a current sharing group Monitoring accuracy Typ Max 120 -40…+125 25 0-165 Automatic restart, 240 ms 110 -100 ms μs % 200 100 ±100 μA mV mV -1 1 % -2 2 % Max 2 x READ_IOUT monitoring accuracy 2 7 A 3 1 % % ±1.7 A ±3.0 A Note 10: See section Initialization Procedure. Note 11: See graph Output Ripple vs External Capacitance and Operating information section Output Ripple and Noise. Note 12: See graph Load Transient vs. External Capacitance and Operating information section External Capacitors. Note 13: Time for reaching 100% of nominal Vout. Note 14: For Vout < 1.0 V accuracy is +/-10 mV. For further deviations see section Output Voltage Adjust using PMBus™. Note 15: Accuracy here means deviation from ideal output voltage level given by configured droop and actual load. Includes line, load and temperature variations. Note 16: For current sharing the Output Voltage Delay Time must be reconfigured to minimum 15 ms. Note 17: For steady state operation above 1.05 x 3.3 V, please contact your local Murata sales representative. Note 18: A minimum load current is not required if Low Power mode is used (monitoring disabled). Note 19: See sections Dynamic Loop Compensation and Power Good. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 13 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Efficiency and Power Dissipation Efficiency vs. Output Current, VI = 5 V Power Dissipation vs. Output Current, VI = 5 V [%] [W] 100 6 5 95 4 90 0.6 V 1.0 V 85 80 0.6 V 3 1.0 V 1.8 V 2 1.8 V 3.3 V 1 3.3 V 75 0 0 5 10 15 20 25 [A] 0 5 10 15 20 25 [A] Efficiency vs. load current and output voltage: TP1 = +25 °C, VI = 5 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Dissipated power vs. load current and output voltage: TP1 = +25 °C, VI = 5 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Efficiency vs. Output Current, VI = 12 V Power Dissipation vs. Output Current, VI = 12 V [%] [W] 100 6 5 95 4 90 0.6 V 1.0 V 85 80 0.6 V 3 1.0 V 1.8 V 2 1.8 V 3.3 V 1 3.3 V 75 0 0 5 10 15 20 25 [A] 0 5 10 15 20 25 [A] Efficiency vs. load current and output voltage at TP1 = +25 °C, VI=12 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Dissipated power vs. load current and output voltage: TP1 = +25 °C, VI=12 V, fsw = 320 kHz, CO = 470 μF/10 mŸ. Efficiency vs. Output Current and Switching Frequency Power Dissipation vs. Output Current and Switching frequency [%] [W] 95 6 5 90 200 kHz 85 200 kHz 4 320 kHz 3 320 kHz 80 480 kHz 2 480 kHz 75 640 kHz 1 640 kHz 70 0 0 5 10 15 20 Efficiency vs. load current and switch frequency at TP1 = +25 °C, VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ. Default configuration except changed frequency 25 [A] 0 5 10 15 20 25 [A] Dissipated power vs. load current and switch frequency at TP1 = +25 °C, VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ. Default configuration except changed frequency www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 14 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Load Transient Load Transient vs. External Capacitance, VO = 1.0 V [mV] 350 280 Universal PID, No NLR Load Transient vs. External Capacitance, VO = 3.3 V [mV] 350 Universal PID, No NLR DLC, No NLR 280 DLC, No NLR 210 Universal PID, Default NLR 210 Universal PID, Default NLR 140 DLC, Default NLR 140 DLC, Default NLR Universal PID, Opt. NLR 70 DLC, Opt. NLR 0 0 1 2 3 4 5 [mF] Universal PID, Opt. NLR 70 DLC, Opt. NLR 0 0 1 2 3 4 5 [mF] Load transient peak voltage deviation vs. external capacitance. Step (6.25-18.75-6.25 A). Parallel coupling of capacitors with 470 μF/10 mŸ, TP1 = +25 °C. VI = 12 V, VO = 1.0 V, fsw = 320 kHz, di/dt = 2 A/μs Load transient peak voltage deviation vs. external capacitance. Step (6.25-18.75-6.25 A). Parallel coupling of capacitors with 470 μF/10 mŸ, TP1 = +25 °C. VI = 12 V, VO = 3.3 V, fsw = 320 kHz, di/dt = 2 A/μs Load transient vs. Switch Frequency Output Load Transient Response, Default Configuration [mV] 350 Universal PID, No NLR 280 DLC, No NLR 210 Universal PID, Default NLR 140 DLC, Default NLR Universal PID, Opt. NLR 70 DLC, Opt. NLR 0 200 300 400 500 600 [kHz] Load transient peak voltage deviation vs. frequency. Step-change (6.25-18.75-6.25 A). TP1 = +25 °C. VI = 12 V, VO = 1.0 V, CO = 470 μF/10 mŸ Output voltage response to load Top trace: output voltage (200 mV/div.). Step-change (6.25-18.75-6.25 A) at: Bottom trace: load current (5 A/div.). TP1 = +25 °C, VI = 12 V, VO = 1.0 V Time scale: (0.1 ms/div.). di/dt = 2 A/μs, fsw = 320 kHz CO = 470 μF/10 mŸ Note: For Universal PID, see section Dynamic Loop Compensation (DLC). www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 15 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Output Current Characteristic Output Current Derating, VO = 0.6 V Output Current Derating, VO = 1.0 V [A] [A] 30 30 3.0 m/s 3.0 m/s 25 25 2.0 m/s 2.0 m/s 20 20 1.0 m/s 1.0 m/s 15 15 0.5 m/s 0.5 m/s 10 10 Nat. Conv. Nat. Conv. 5 5 0 0 50 60 70 80 90 100 110 120 [°C] 50 60 70 80 90 100 110 120 [°C] Available load current vs. ambient air temperature and airflow at VO = 0.6 V, VI = 12 V. See Thermal Consideration section. Available load current vs. ambient air temperature and airflow at VO = 1.0 V, VI = 12 V. See Thermal Consideration section. Output Current Derating, VO = 1.8 V Output Current Derating, VO = 3.3 V [A] [A] 30 30 3.0 m/s 3.0 m/s 25 25 2.0 m/s 2.0 m/s 20 20 1.0 m/s 1.0 m/s 15 15 0.5 m/s 0.5 m/s 10 10 Nat. Conv. Nat. Conv. 5 5 0 0 30 40 50 60 70 80 90 100 110 120 [°C] 30 Available load current vs. ambient air temperature and airflow at VO = 1.8 V, VI = 12 V. See Thermal Consideration section. 40 50 60 70 80 90 100 110 120 [°C] Available load current vs. ambient air temperature and airflow at VO = 3.3 V, VI = 12 V. See Thermal Consideration section. Current Limit Characteristics, VO = 1.0 V Current Limit Characteristics, VO = 3.3 V [V] [V] 1,2 4,0 1,0 3,0 0,8 4.5 V 0,6 5.0 V VI = 4.5 V VI = 5.0, 12, 14 V 0,4 4.5 V 5.0 V 2,0 12 V 12 V 14 V VI = 12, 14 V VI = 4.5, 5.0 V 14 V 1,0 0,2 0,0 0,0 25 27 29 31 33 35 [A] 25 27 29 31 33 35 [A] Output voltage vs. load current at TP1 = +25 °C, VO = 1.0 V. Output voltage vs. load current at TP1 = +25 °C, VO = 3.3 V. Note: Output enters hiccup mode at current limit. Note: Output enters hiccup mode at current limit. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 16 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Output Voltage Output Ripple & Noise, VO = 1.0 V Output Ripple & Noise, VO = 3.3 V Output voltage ripple at: TP1 = +25 °C, Trace: output voltage (20 mV/div.). Time scale: (2 μs/div.). VI = 12 V, CO = 470 μF/10 mŸ IO = 25 A Output voltage ripple at: TP1 = +25 °C, Trace: output voltage (20 mV/div.). Time scale: (2 μs/div.). VI = 12 V, CO = 470 μF/10 mŸ IO = 25 A Output Ripple vs. Input Voltage Output Ripple vs. Frequency [mVpk-pk] [mVpk-pk] 50 100 40 80 0.6 V 0.6 V 30 1.0 V 1.8 V 20 60 1.0 V 1.8 V 40 3.3 V 3.3 V 10 20 0 5 7 9 11 0 [V] 13 200 300 400 500 600 [kHz] Output voltage ripple Vpk-pk at: TP1 = +25 °C, CO = 470 μF/10 mŸ, IO = 25 A. Output voltage ripple Vpk-pk at: TP1 = +25 °C, VI = 12 V, CO = 470 μF/10 mŸ, IO = 25 A. Default configuration except changed frequency. Output Ripple vs. External Capacitance Load regulation, VO = 1.0 V [mV] [V] 50 1,010 40 0.6V 30 1,005 4.5 V 1.0 V 1.8 V 20 3.3 V 10 0 0 1 2 3 4 5 [mF] Output voltage ripple Vpk-pk at: TP1 = +25 °C, VI = 12 V. IO = 25 A. Parallel coupling of capacitors with 470 μF/10 mŸ 5.0 V 1,000 12 V 14 V 0,995 0,990 0 5 10 15 20 25 [A] Load regulation at Vo=1.0 V, TP1 = +25 °C, CO = 470 μF/10 mŸ www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 17 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Typical Characteristics Start-up and shut-down Start-up by input source Start-up enabled by connecting VI at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Shut-down by input source Top trace: output voltage (0.5 V/div.). Bottom trace: input voltage (5 V/div.). Time scale: (20 ms/div.). Start-up by CTRL signal Start-up by enabling CTRL signal at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Shut-down enabled by disconnecting VI at: TP1 = +25 °C, VI = 12 V, VO = 1.0 V CO = 470 μF/10 mŸ, IO = 25 A Top trace: output voltage (0.5 V/div). Bottom trace: input voltage (5 V/div.). Time scale: (2 ms/div.). Shut-down by CTRL signal Top trace: output voltage (0.5 V/div.). Bottom trace: CTRL signal (2 V/div.). Time scale: (20 ms/div.). Shut-down enabled by disconnecting VI Top trace: output voltage (0.5 V/div). at: Bottom trace: CTRL signal (2 V/div.). TP1 = +25 °C, VI = 12 V, VO = 1.0 V Time scale: (2 ms/div.). CO = 470 μF/10 mŸ, IO = 25 A www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 18 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series EMC Specification Output Ripple and Noise Conducted EMI measured according to test set-up below. The fundamental switching frequency is 320 kHz at VI = 12 V, max IO. Output ripple and noise is measured according to figure below. 50 mm conductor Vout Tantalum Capacitor Output 10 μ F Capacitor 470 μ F/10 m Ω +S –S GND Ceramic Capacitor 0.1 μ F Load Conducted EMI Input terminal value (typical for default configuration) A 50 mm conductor works as a small inductor forming together with the two capacitors as a damped filter. 50 mm conductor BNC-contact to oscilloscope Output ripple and noise test set-up. Operating information Power Management Overview EMI without filter To spectrum analyzer RF Current probe 1kHz – 50MHz Battery supply Resistive load C1 POL 50mm C1 = 10uF / 600VDC Feed- Thru RF capacitor This product is equipped with a PMBus™ interface. The product incorporates a wide range of readable and configurable power management features that are simple to implement with a minimum of external components. Additionally, the product includes protection features that continuously safeguard the load from damage due to unexpected system faults. A fault is also shown as an alert on the SALERT pin. The following product parameters can continuously be monitored by a host: Input voltage, output voltage/current, and internal temperature. If the monitoring is not needed it can be disabled and the product enters a low power mode reducing the power consumption. The protection features are not affected. The product is delivered with a default configuration suitable for a wide range operation in terms of input voltage, output voltage, and load. The configuration is stored in an internal Non-Volatile Memory (NVM). All power management functions can be reconfigured using the PMBus™ interface. Please contact your local Murata Power Solutions representative for design support of custom configurations or appropriate SW tools for design and download of your own configurations. Input Voltage 200mm 800mm Conducted EMI test set-up The input voltage range, 4.5 - 14 V, makes the product easy to use in intermediate bus applications when powered by a non-regulated bus converter or a regulated bus converter. See Ordering Information for input voltage range. Layout Recommendations The radiated EMI performance of the product will depend on the PWB layout and ground layer design. It is also important to consider the stand-off of the product. If a ground layer is used, it should be connected to the output of the product and the equipment ground or chassis. A ground layer will increase the stray capacitance in the PWB and improve the high frequency EMC performance. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 19 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Input Under Voltage Lockout, UVLO The product monitors the input voltage and will turn-on and turn-off at configured levels. The default turn-on input voltage level setting is 4.20 V, whereas the corresponding turn-off input voltage level is 3.85 V. Hence, the default hysteresis between turn-on and turn-off input voltage is 0.35 V. Once an input turn-off condition occurs, the device can respond in a number of ways as follows: 1. Continue operating without interruption. The unit will continue to operate as long as the input voltage can be supported. If the input voltage continues to fall, there will come a point where the unit will cease to operate. 2. Continue operating for a given delay period, followed by shutdown if the fault still exists. The device will remain in shutdown until instructed to restart. 3. Initiate an immediate shutdown until the fault has been cleared. The user can select a specific number of retry attempts. The default response from a turn-off is an immediate shutdown of the device. The device will continuously check for the presence of the fault condition. If the fault condition is no longer present, the product will be re-enabled. The turn-on and turn-off levels and response can be reconfigured using the PMBus™ interface. Remote Control Vext CTRL GND The product is equipped with a remote control function, i.e., the CTRL pin. The remote control can be connected to either the primary negative input connection (GND) or an external voltage (Vext), which is a 3 - 5 V positive supply voltage in accordance to the SMBus Specification version 2.0. The CTRL function allows the product to be turned on/off by an external device like a semiconductor or mechanical switch. By default the product will turn on when the CTRL pin is left open and turn off when the CTRL pin is applied to GND. The CTRL pin has an internal pull-up resistor. When the CTRL pin is left open, the voltage generated on the CTRL pin is max 5.5 V. If the device is to be synchronized to an external clock source, the clock frequency must be stable prior to asserting the CTRL pin. The product can also be configured using the PMBus™ interface to be “Always on,” or turn on/off can be performed with PMBus™ commands. Input and Output Impedance The impedance of both the input source and the load will interact with the impedance of the product. It is important that the input source has low characteristic impedance. The performance in some applications can be enhanced by addition of external capacitance as described under External Decoupling Capacitors. If the input voltage source contains significant inductance, the addition a capacitor with low ESR at the input of the product will ensure stable operation. External Capacitors Input capacitors: The input ripple RMS current in a buck converter is equal to Eq. 1. I inputRMS I load D 1  D  , where I load is the output load current and D is the duty cycle. The maximum load ripple current becomes I load 2 . The ripple current is divided into three parts, i.e., currents in the input source, external input capacitor, and internal input capacitor. How the current is divided depends on the impedance of the input source, ESR and capacitance values in the capacitors. A minimum capacitance of 300 μF with low ESR is recommended. The ripple current rating of the capacitors must follow Eq. 1. For high-performance/transient applications or wherever the input source performance is degraded, additional low ESR ceramic type capacitors at the input is recommended. The additional input low ESR capacitance above the minimum level insures an optimized performance. Output capacitors: When powering loads with significant dynamic current requirements, the voltage regulation at the point of load can be improved by addition of decoupling capacitors at the load. The most effective technique is to locate low ESR ceramic and electrolytic capacitors as close to the load as possible, using several capacitors in parallel to lower the effective ESR. The ceramic capacitors will handle highfrequency dynamic load changes while the electrolytic capacitors are used to handle low frequency dynamic load changes. Ceramic capacitors will also reduce high frequency noise at the load. It is equally important to use low resistance and low inductance PWB layouts and cabling. External decoupling capacitors are a part of the control loop of the product and may affect the stability margins. Stable operation is guaranteed for the following total capacitance CO in the output decoupling capacitor bank where Eq. 2. >Cmin , Cmax @ >300, 15000@ μF. CO The decoupling capacitor bank should consist of capacitors which has a capacitance value larger than C t C min and has an ESR range of Eq. 3. ESR >ESRmin , ESRmax @ >5, 30@ mΩ The control loop stability margins are limited by the minimum time constant W min of the capacitors. Hence, the time constant of the capacitors should follow Eq. 4. Eq. 4. W t W min Cmin ESRmin 1.5 Ps This relation can be used if your preferred capacitors have parameters outside the above stated ranges in Eq. 2 and Eq.3. x If the capacitors capacitance value is C  C min one must use at least N capacitors where C ªC º N t « min » and ESR t ESRmin min . C C « » x If the ESR value is ESR ! ESR max one must use at least N capacitors of that type where ª ESR º C min N t« . » and C t ESR N max » « x If the ESR value is ESR  ESR min the capacitance value should be C t C min ESRmin . ESR www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 20 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series For a total capacitance outside the above stated range or capacitors that do not follow the stated above requirements above a re-design of the control loop parameters will be necessary for robust dynamic operation and stability. Control Loop The product uses a voltage-mode synchronous buck controller with a fixed frequency PWM scheme. Although the product uses a digital control loop, it operates much like a traditional analog PWM controller. As in the analog controller case, the control loop compares the output voltage to the desired voltage reference and compensation is added to keep the loop stable and fast. The resulting error signal is used to drive the PWM logic. Instead of using external resistors and capacitors required with traditional analog control loops, the product uses a digital Proportional-Integral-Derivative (PID) compensator in the control loop. The characteristics of the control loop is configured by setting PID compensation parameters. These PID settings can be reconfigured using the PMBus™ interface. The DLC algorithm can also be initiated manually by sending the AUTO_ COMP_CONTROL command. The DLC can also be configured with Auto Comp Gain Control. This scales the DLC results to allow a trade-off between transient response and steadystate duty cycle jitter. A setting of 100% will provide the fastest transient response while a setting of 10% will produce the lowest jitter. The default is 50%. Changing DLC and PID Setting Some caution must be considered while DLC is enabled and when it is changed from enabled or disabled. When operating, the controller IC uses the settings loaded in its (volatile) RAM memory. When the input power is applied the RAM settings are retrieved from the pin-strap resistors and the two non-volatile memories (DEFAULT and USER). The sequence is described in the “Initialization Procedure” section. Control Loop Compensation Setting When DLC is enabled: The products without DLC are by default configured with a robust control loop compensation setting (PID setting) which allows for a wide range operation of input and output voltages and capacitive loads as defined in the section External Decoupling Capacitors. For an application with a specific input voltage, output voltage, and capacitive load, the control loop can be optimized for a robust and stable operation and with an improved load transient response. This optimization will minimize the amount of required output decoupling capacitors for a given load transient requirement yielding an optimized cost and minimized board space. The optimization together with load step simulations can be made using the Murata Power Designer software. When DLC is enabled, the normal sequence (after input power has been applied) that a value stored in the user non-volatile memory overwrites any previously loaded value does not apply for the PID setting (stored in the PID_TAPS register). The PID setting in the user non-volatile memory is ignored and a non-configurable default PID setting is loaded to RAM to act as a safe starting value for the DLC. Once the output has been enabled and the DLC algorithm has found a new optimized PID setting it will be loaded in RAM and used by the control loop. Dynamic Loop Compensation (DLC) Only some of the products that this specification covers have this feature (see section Ordering Information). The DLC feature might in some documents be referred to as “Auto Compensation” or “Auto Tuning” feature. When saving changes to the user non-volatile memory, all changes made to the content of RAM will be saved. This also includes the default PID setting (loaded to RAM to act as a safe starting value) or the PID setting changed by the DLC algorithm after enabling output. The result is that as long as DLC is enabled the PID setting in the user non-volatile memory is ignored, but it might accidentally get overwritten. When changing DLC from disabled to enabled: The DLC feature measures the characteristics of the power train and calculates the proper compensator PID coefficients. A non-configurable default PID setting is loaded to RAM to act as a safe starting value for the DLC (same as above). The default configuration is that once the output voltage ramp up has completed, the DLC algorithm will begin and a new optimized compensator solution (PID setting) will be found and implemented. The DLC algorithm typically takes between 50 ms and 200 ms to complete. When changing DLC from enabled to disabled: By the PMBus™ command AUTO_COMP_CONFIG the user may select between several different modes of operation: When DLC is disabled: Disable Autocomp once, will run DLC algorithm each time the output is enabled (default configuration) Autocomp every second will initiate a new DLC algorithm each 1 second Autocomp every minute will initiate a new DLC algorithm every minute. The DLC can also be configured to run once only after the first ramp up (after input power have been applied) and to use that temporary stored PID settings in all subsequent ramps. If input power is cycled a new DLC algorithm will be performed after the first ramp up. The default setting is however to run the DLC algorithm after every ramp up. When changing DLC from enabled to disabled, the PID setting in the user nonvolatile memory will be loaded to RAM. Any new optimized PID setting in RAM will be lost, if not first stored to the user non-volatile memory. When DLC is disabled and input power has been applied, the PID setting in the user non-volatile memory will be loaded to RAM and used in the control loop. The original PID setting in the user non-volatile memory is quite slow and not recommended for optimal performance. If DLC is disabled it is recommended to either: 1. Use the DLC to find optimized PID setting. 2. Use Murata Power Designer to find appropriate PID setting. 3. Use Universal PID as defined below. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 21 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series The Universal PID setting (taps) is: VO [V] 0.60 A = 4580.75, B = -8544.00, C = 3972.81 Write 0x7CF84DFE85807D8F26 to PID_TAPS register and write command STORE_USER_ALL Note that if DLC is enabled, for best results VI must be stable before DLC algorithm begins. Load Transient Response Optimization The product incorporates a Non-Linear transient Response, NLR, loop that decreases the response time and the output voltage deviation during a load transient. The NLR results in a higher equivalent loop bandwidth than is possible using a traditional linear control loop. The product is pre-configured with appropriate NLR settings for robust and stable operation for a wide range of input voltage and a capacitive load range as defined in the section External Decoupling Capacitors. For an application with a specific input voltage, output voltage, and capacitive load, the NLR configuration can be optimized for a robust and stable operation and with an improved load transient response. This will also reduce the amount of output decoupling capacitors and yield a reduced cost. However, the NLR slightly reduces the efficiency. In order to obtain maximal energy efficiency the load transient requirement has to be met by the standard control loop compensation and the decoupling capacitors. The NLR settings can be reconfigured using the PMBus™ interface. Remote Sense The product has remote sense that can be used to compensate for voltage drops between the output and the point of load. The sense traces should be located close to the PWB ground layer to reduce noise susceptibility. Due to derating of internal output capacitance the voltage drop should be kept below VDROPMAX = (5.25 – VOUT) / 2. A large voltage drop will impact the electrical performance of the regulator. If the remote sense is not needed, +S should be connected to VOUT and −S should be connected to GND. Output Voltage Adjust using Pin-strap Resistor VSET R SET PREF Using an external Pin-strap resistor, RSET, the output voltage can be set in the range 0.6 V to 3.3 V at 28 different levels shown in the table below. The resistor should be applied between the VSET pin and the PREF pin. RSET also sets the maximum output voltage, see section “Output Voltage Range Limitation.” The resistor is sensed only during product start-up. Changing the resistor value during normal operation will not change the output voltage. The input voltage must be at least 1 V larger than the output voltage in order to deliver the correct output voltage. See Ordering Information for output voltage range. The following table shows recommended resistor values for RSET. Maximum 1% tolerance resistors are required. 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 RSET[kΩ] 10 11 12.1 13.3 14.7 16.2 17.8 19.6 21.5 23.7 26.1 28.7 31.6 1.25 1.30 1.40 34.8 38.3 42.2 VO [V] 1.50 1.60 1.70 1.80 1.90 2.00 2.10 2.20 2.30 2.50 3.00 3.30 RSET[kΩ] 46.4 51.1 56.2 61.9 68.1 75 82.5 90.9 100 110 121 133 The output voltage and the maximum output voltage can be pin strapped to three fixed values by connecting the VSET pin according to the table below. VSET VO [V] 0.60 1.2 2.5 Shorted to PREF Open “high impedance” Logic High, GND as reference Output Voltage Adjust using PMBus™ The output voltage set by pin-strap can be overridden by configuration file or by using a PMBus™ command. See Electrical Specification for adjustment range. When setting the output voltage by configuration file or by a PMBus™ command, the specified output voltage accuracy is valid only when the set output voltage level falls within the same bin range as the voltage level defined by the pin-strap resistor RSET. The applicable bin ranges are defined in the table below. Valid accuracy for voltage levels outside the applicable bin range is two times the specified. Example: Nominal VO is set to 1.10 V by RSET = 26.1 kΩ. 1.10 V falls within the bin range 0.988-1.383 V, thus specified accuracy is valid when adjusting VO within 0.988-1.383V. VO bin ranges [V] 0.600 – 0.988 0.988 – 1.383 1.383 – 1.975 1.975 – 2.398 2.398 – 2.963 2.963 – 3.753 Output Voltage Range Limitation The output voltage range that is possible to set by configuration or by the PMBus™ interface is limited by the pin-strap resistor RSET. The maximum output voltage is set to 110% of the nominal output value defined by RSET, VO,MAX = 1.1 x VO,RSET. This protects the load from an over voltage due to an accidental wrong PMBus™ command. www.murata-ps.com/support MDC_OKDx-T/25-W12-xxx-C.A07 Page 22 of 41 OKDx-T/25-W12-xxx-C 25A Digital PoL DC-DC Converter Series Output Voltage Adjust Limitation using PMBus™ Switching Frequency In addition to the maximum output voltage limitation by the pin-strap resistor RSET, there is also a limitation in how much the output voltage can be increased while the output is enabled. If output is disabled then RSET resistor is the only limitation. The fundamental switching frequency is 320 kHz, which yields optimal power efficiency. The switching frequency can be set to any value between 200 kHz and 640 kHz using the PMBus™ interface. The switching frequency will change the efficiency/power dissipation, load transient response and output ripple. For optimal control loop performance in a product without DLC, the control loop must be re-optimized when changing the switching frequency. Example: If the output is enabled with output voltage set to 1.0 V, then it is only possible to adjust/change the output voltage up to 1.7- V as long as the output is enabled. VO setting when enabled [V] 0.000 – 0.988 0.988 – 1.383 1.383 – 1.975 1.975 – 2.398 2.398 – 2.963 2.963 – 3.753 VO set range while enabled [V] ~0.2 to >1.2 ~0.2 to >1.7 ~0.2 to >2.5 ~0.2 to >2.97 ~0.2 to >3.68 ~0.2 to >4.65 Over Voltage Protection (OVP) The product includes over voltage limiting circuitry for protection of the load. The default OVP limit is 15% above the nominal output voltage. If the output voltage exceeds the OVP limit, the product can respond in different ways: 1. Initiate an immediate shutdown until the fault has been cleared. The user can select a specific number of retry attempts. 2. Turn off the high-side MOSFET and turn on the low-side MOSFET. The low-side MOSFET remains ON until the device attempts a restart, i.e. the output voltage is pulled to ground level (crowbar function). The default response from an overvoltage fault is to immediately shut down as in 2. The device will continuously check for the presence of the fault condition, and when the fault condition no longer exists the device will be reenabled. For continuous OVP when operating from an external clock for synchronization, the only allowed response is an immediate shutdown. The OVP limit and fault response can be reconfigured using the PMBus™ interface. Under Voltage Protection (UVP) The product includes output under voltage limiting circuitry for protection of the load. The default UVP limit is 15% below the nominal output voltage. The UVP limit can be reconfigured using the PMBus™ interface. Power Good The product provides a Power Good (PG) flag in the Status Word register that indicates the output voltage is within a specified tolerance of its target level and no fault condition exists. If specified in section Connections, the product also provides a PG signal output. The PG pin is active high and by default open-drain but may also be configured as push-pull via the PMBus™ interface. By default, the PG signal will be asserted when the output reaches above 90% of the nominal voltage, and de-asserted when the output falls below 85% of the nominal voltage. These limits may be changed via the PMBus™ interface. A PG delay period is defined as the time from when all conditions within the product for asserting PG are met to when the PG signal is actually asserted. The default PG delay is set to 10 ms. This value can be reconfigured using the PMBus™ interface. For products with DLC the PG signal is by default asserted directly after the DLC operation have been completed. If DLC is disabled the configured PG delay will be used. This can be reconfigured using the PMBus™ interface. Synchronization Synchronization is a feature that allows multiple products to be synchronized to a common frequency. Synchronized products powered from the same bus eliminate beat frequencies reflected back to the input supply, and also reduces EMI filtering requirements. Eliminating the slow beat frequencies (usually