UCE Series www.murata-ps.com m Isolated, High-Density, Eighth-Brick 100W DC/DC Converters FEATURES ■ RoHS compliant Typical unit ■ Industry standard eighth-brick pinout and package ■ Outputs from 1.5V to 12V up to 100W ■ Low profile 0.4" height with 0.9" x 2.3" outline dimensions ■ 36 to 75 Vdc input range (48V nominal) ■ Fully isolated, 2250 Vdc (BASIC) insulation ■ Outstanding thermal performance and derating ■ Extensive self-protection and short circuit features with no output reverse conduction ■ On/Off control, trim and sense functions ■ Interleaved synchronous rectification yields high efficiency over 90% ■ Fully protected against temperature and voltage limits ■ Designed to meet UL/EN/IEC 60950-1 and CAN/CSA C22.2 No. 60950-1 safety approvals For efficient, fully isolated DC power in the smallest space, the UCE open frame DC/DC converter series fit in industry-standard “eighth brick” outline dimensions and mounting pins (on quarter-brick pinout). PRODUCT OVERVIEW Units are offered with fixed output voltages from 1.5 to 12 Volts and currents up to 40 Amps. UCEs operate over a wide temperature range (up to +85 degrees Celsius at moderate airflow) with full rated power. Interleaved synchronous rectifier topology yields excellent efficiency over 90% and no reverse output conduction. UCE’s achieve these impressive mechanical and environmental specs while delivering excellent electrical performance in a through-hole package. Overall noise is typically 50 mV pk-pk (low voltage models) with fast step response. These converters offer tight output regulation and high stability even with no load. The unit is fully protected against input undervoltage, output overcurrent and short circuit. An on-board temperature sensor shuts down the converter if thermal limits are reached. “Hiccup” output protection automatically restarts the converter when the fault is removed. A convenient remote On/Off control input enables phased startup and shutdown in multi-voltage applications. To compensate for longer wiring and to retain output voltage accuracy at the load, UCEs employ a Sense input to dynamically correct for ohmic losses. A trim input may be connected to a user’s adjustment potentiometer or trim resistors for output voltage calibration. The UCE will tolerate substantial capacitive loading for bypass-cap applications. UCEs include industry-standard safety certifications and BASIC I/O insulation provides input/output isolation to 2250V. Radiation emission testing is performed to widely-accepted EMC standards. SIMPLIFIED BLOCK DIAGRAM +SENSE (7) +VIN (3) +VOUT (8) SWITCH CONTROL −VOUT (4) –VIN (1) PULSE TRANSFORMER PWM CONTROLLER OPTO ISOLATION INPUT UNDERVOLTAGE, INPUT OVERVOLTAGE, AND OUTPUT OVERVOLTAGE COMPARATORS REFERENCE & ERROR AMP REMOTE ON/OFF CONTROL (2) −SENSE (5) VOUT TRIM (6) Typical topology is shown. Figure 1. Simplified Block Diagram For full details go to www.murata-ps.com/rohs www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 1 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE Output Model Family VOUT (V) IOUT (A) Power (W) UCE-1.2/40-D48N-C 1.2 40 48 UCE-1.5/20-D48N-C 1.5 20 30 UCE-1.5/40-D48N-C 1.5 40 60 UCE-1.8/30-D48N-C 1.8 30 UCE-2.5/20-D48N-C 2.5 20 UCE-2.5/40-D48N-C 2.5 40 100 UCE-3.3/15-D48N-C 3.3 15 49.5 UCE-3.3/30-D48N-C 3.3 30 99 UCE-5/10-D48N-C 5 10 50 UCE-5/20-D48N-C 5 20 100 UCE-12/4.2-D48N-C UCE-12/8.3-D48N-C 12 12 4.2 8.3 50.4 99.6 Input Ripple & Noise (mVp-p) Typ. Max. Regulation (max.) Line Load VIN Nom. Range (V) (V) IIN, no load (mA) IIN, full load (A) Efficiency Min. Typ. 50 100 54 30 80 Please contact Murata Power Solutions for further information. ±0.3% 48 36-75 50 0.72 85% Please contact Murata Power Solutions for further information. ±0.125% ±0.25% 45 1.28 87% 50 50 80 ±0.125% 50 100 50 100 ±0.125% ±0.1% ±0.125% 48 ±0.25% 300 ±0.125% 36-75 91% Please contact Murata Power Solutions for further information. ±0.25% 1.15 86% 60 ±0.2% 2.27 89% 90% 91% ±0.25% 48 ±0.25% 36-75 50 1.14 88% 88% Please contact Murata Power Solutions for further information. 150 200 87% ±0.15% 30 1.15 88% 90.5% Please contact Murata Power Solutions for further info.. 1.14 2.31 50 Package Case Pinout C56 P32 C56 P32 C56 P32 92% 90% 86% M Please refer to the model number structure for additional ordering part numbers and options . PART NUMBER STRUCTURE U CE - 3.3 / 30 - D48 N B H LX - C Output Configuration: RoHS Hazardous Materials compliance C = RoHS6 (does not claim EU RoHS exemption 7b–lead in solder), standard Y = RoHS5 (with lead), optional, special quantity order U = Unipolar/Single Pin Length Option (Through-hole packages only) Eighth-Brick Package Blank = Standard pin length 0.180 inches (4.6mm) L1 = Pin length 0.110 inches (2.79mm)* L2 = Pin length 0.145 inches (3.68mm)* * Special quantity order is required. Nominal Output Voltage Maximum Rated Output Current in Amps Input Voltage Range: D48 = 36-75V, 48V nominal Conformal coating (optional) Blank = no coating, standard H = Coating added, optional, special quantity order Baseplate (optional, not available on some models) Blank = No baseplate, standard B = Baseplate installed, optional, special quantity order On/Off Control Polarity N = Negative polarity, standard P = Positive polarity, optional www.murata-ps.com Note: Some model combinations may not be available. Contact Murata Power Solutions for availability. Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 2 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters SPECIFICATIONS INPUT CHARACTERISTICS Model Family UCE-1.5/20-D48 UCE-1.8/30-D48 UCE-2.5/20-D48 UCE-3.3/15-D48 UCE-3.3/30-D48 UCE-5/10-D48 UCE-5/20-D48 UCE-12/4.2-D48 UCE-12/8.3-D48 Remote On/Off Control Under- Reflected Start-up voltage (back) Internal Reverse threshold Output ShutRipple Low Line Standby Input Filter Polarity Positive Logic Negative Logic Inrush Min. down Current Transient Short (VIN=min.) Mode Type Protection Current “P” Model “N” Model (A) (mA) Circuit (V) (mA)② (A) (mA) Suffix Suffix A2sec (mA) 34 34.5 34 34 32 32.5 32 32 32 32 31.5 32 32 10-30, model dependent 0.05 A2sec 50-150, model dependent 0.97 1.72 1.53 1.54 3.06 1.53 3.00 1.52 3.07 L-C 1-10, model dependent See notes 1.0 Pi Pi OFF=Ground OFF=open or pin to +1V max. +2.5V to ON=open or +15V max. +3.5 to +15V ON=Ground pin to max. +0.8V max. L-C OUTPUT CHARACTERISTICS Model Family UCE-1.5/20-D48 UCE-1.8/30-D48 UCE-2.5/20-D48 UCE-3.3/15-D48 UCE-3.3/30-D48 UCE-5/10-D48 UCE-5/20-D48 UCE-12/4.2-D48 UCE-12/8.3-D48 VOUT Accuracy 50% Load % of VNOM Capacitive Loading Max. Low ESR <0.02Ω Max. resistive load Adjustment Temperature μF Range Coefficient 10,000 10,000 10,000 10,000 10,000 1000 10,000 1000 1000 ±1% –10 to +10% of Vnom. ±0.02% of Vout range per °C Minimum Loading No minimum load Remote Ripple/ Sense Noise Compen- (20 MHz Line/Load sation bandwidth) Regulation +10% Efficiency See ordering guide Current Limit Inception 98% of Vout, after warmup A 24.5 36 32 24 35 15. 23 min. 5.5 12 ISOLATION CHARACTERISTICS Model Family Input to Output Min. V Input to baseplate Min. V Baseplate to output Min. V UCE-1.5/20-D48 UCE-1.8/30-D48 Isolation Resistance MΩ Isolation Capacitance pF Isolation Safety Rating 100 10 UCE-2.5/20-D48 UCE-3.3/15-D48 UCE-3.3/30-D48 2250 1500 1500 UCE-5/10-D48 UCE-5/20-D48 1000 Basic Insulation 100 UCE-12/4.2-D48 UCE-12/8.3-D48 www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 3 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters SPECIFICATIONS, CONTINUED MISCELLANEOUS CHARACTERISTICS Model Family UCE-1.5/20-D48 UCE-1.8/30-D48 UCE-2.5/20-D48 UCE-3.3/15-D48 UCE-3.3/30-D48 UCE-5/10-D48 UCE-5/20-D48 UCE-12/4.2-D48 UCE-12/8.3-D48 Calculated MTBF4 Operating Temperature Range with derating (°C) Overvoltage Protection12 Operating Storage Thermal Short (V) Via PCB Temperature Protection/ Circuit magnetic Short Circuit Relative Temperature Range Shutdown Current feedback Protection Short Circuit Humidity (no derating) (°C) (ºC) (A) (V) Method Duration16 (non-condensing) 120 1.8 M HRS TBC −40 to +85 −40 to +120 2.6 M HRS 2.7 M HRS TBC 2.4 M HRS Dynamic Load Remote On/ Response Off to VOUT VIN to VOUT (50-75-50% regulated load step) to 1% regulated (Max.) (Max.) of final value, mSec μSec 100 150 100 200 50 100 100 max. 30 50 4.25 110 0.5 7 max. 125 5 14.5 Current limiting, hiccup autorestart. Remove overload for recovery. Continuous, output shorted to ground. No damage. to +85°C/85% ABSOLUTE MAXIMUM RATINGS Start-up Time Model Family 5 −55 to +125 DYNAMIC CHARACTERISTICS UCE-1.5/20-D48 UCE-1.8/30-D48 UCE-2.5/20-D48 UCE-3.3/15-D48 UCE-3.3/30-D48 UCE-5/10-D48 UCE-5/20-D48 UCE-12/4.2-D48 UCE-12/8.3-D48 1.95 2.8 V. max 3 TBC 50 10 50 50 15 50 10 60 50 50 10 50 50 10 50 10 60 50 Switching Frequency KHz 480 400 350 480 380 400 330 200 www.murata-ps.com Input Voltage: Continuous: 48 Volt input models Transient (100 mSec. Max.) 48 Volt input models 75 Volts On/Off Control +15 Volts Input Reverse Polarity Protection 5 Amps, 10 sec. max. Output Overvoltage Protection Magnetic feedback. See specifications. Output Current Current-limited. Devices can withstand sustained short circuit without damage. 100 Volts Storage Temperature –40 to +125°C. Lead Temperature See soldering guidelines. Absolute maximums are stress ratings. Exposure of devices to greater than any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those listed in the Performance/Functional Specifications Table is not implied or recommended. Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 4 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters SPECIFICATIONS, CONTINUED PERFORMANCE SPECIFICATION NOTES (1) All models are tested and specified with external 1||10 μF ceramic/tantalum output capacitors and no external input capacitor. All capacitors are low ESR types. These capacitors are necessary to accommodate our test equipment and may not be required to achieve specified performance in your applications. All models are stable and regulate within spec under no-load conditions. General conditions for Specifications are +25 deg.C, VIN = nominal, VOUT = nominal, full load. Adequate airflow must be supplied for extended testing under power. (2) Input Ripple Current is tested and specified over a 5 Hz to 20 MHz bandwidth. Input filtering is CIN = 33 μF, 100V tantalum, CBUS = 220 μF, 100V electrolytic, LBUS = 12 μH. (3) Note that Maximum Power Derating curves indicate an average current at nominal input voltage. At higher temperatures and/or lower airflow, the DC/DC converter will tolerate brief full current outputs if the total RMS current over time does not exceed the Derating curve. All Derating curves are presented at sea level altitude. Be aware of reduced power dissipation with increasing density altitude. (4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3, ground fixed conditions, Tpcboard=+25 deg.C, full output load, natural air convection. (5) The On/Off Control is normally controlled by a switch. But it may also be driven with external logic or by applying appropriate external voltages which are referenced to Input Common. The On/Off Control Input should use either an open collector or open drain transistor. (7) The outputs are not intended to sink appreciable reverse current. This may damage the outputs. (8) Output noise may be further reduced by adding an external filter. See I/O Filtering and Noise Reduction. (9) All models are fully operational and meet published specifications, including “cold start” at –40ºC. (10) Regulation specifications describe the deviation as the line input voltage or output load current is varied from a nominal midpoint value to either extreme. (11) Alternate pin length and/or other output voltages are available under special quantity order. (12) Output current limit is non-latching. When the overcurrent fault is removed, the converter will immediately recover. (13) Do not exceed maximum power specifications when adjusting the output trim. (14) At zero output current, the output may contain low frequency components which exceed the ripple specification. The output may be operated indefinitely with no load. (15) If reverse polarity is accidentally applied to the input, a body diode will become forward biased and will conduct considerable current. To ensure reverse input protection with full output load, always connect an external input fuse in series with the +VIN input. Use approximately twice the full input current rating with nominal input voltage. (6) Short circuit shutdown begins when the output voltage degrades approximately 2% from the selected setting. PHYSICAL CHARACTERISTICS Outline dimensions See mechanical specs (below) Pin material Copper alloy Pin diameter 0.04/0.062" (1.016/1.524mm) Pin finish Nickel underplate with gold overplate UCE-1.5/20-D48 0.67 ounces (19 grams) UCE-1.8/30-D48, UCE-2.5/20-D48 Weight UCE-5/10-D48 0.71 ounces (20 grams) UCE-5/20-D48 UCE-12/4.2-D48 UCE-3.3/15-D48 1 ounce (28 grams) UCE-3.3/30-D48, UCE-12/8.3-D48 0.81 ounces (23 grams) Electromagnetic interference (conducted and radiated) (external filter required) FCC part 15, class B, EN55022 Safety Designed to meet UL/cUL 60950-1, CSA-C22.2 No. 60950-1, IEC/EN 60950-1 SOLDERING GUIDELINES Murata Power Solutions recommends the specifications below when installing these converters. These specifications vary depending on the solder type. Exceeding these specifications may cause damage to the product. Be cautious when there is high atmospheric humidity. We strongly recommend a mild pre-bake (100ºC. for 30 minutes). Your production environment may differ therefore please thoroughly review these guidelines with your process engineers. Wave Solder Operations for through-hole mounted products (THMT) For Sn/Ag/Cu based solders: Maximum Preheat Temperature Maximum Pot Temperature Maximum Solder Dwell Time 115ºC. 270ºC. 7 seconds For Sn/Pb based solders: Maximum Preheat Temperature Maximum Pot Temperature Maximum Solder Dwell Time 105ºC. 250ºC. 6 seconds www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 5 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters MECHANICAL SPECIFICATIONS Without Baseplate 2.30 (58.4) 0.40 max (10.2) 0.18 (4.6) 0.015 minimum clearance between standoffs and highest component 2.00 (50.8) PINS 1-3, 5-7: 0.040±0.001 (1.016±0.025) dia. PINS 4, 8: 0.060±0.001 (1.524±0.025) dia. 0.300 (7.62) 0.300 (7.62) 1 4 Dimensions are in inches (mm shown for ref. only). 0.15 0.900 (3.81) (22.9) 2 Third Angle Projection 3 Bottom view Tolerances (unless otherwise specified): .XX ± 0.02 (0.5) .XXX ± 0.010 (0.25) Angles ± 2˚ Pin 8 Components are shown for reference only. With Baseplate PINS 1-3, 5-7: 0.040±0.001 (1.016±0.025) dia. PINS 4, 8: 0.060±0.001 (1.524±0.025) dia. Screw length must not go through baseplate. Please note that some competitive units may use different pin numbering or alternate outline views. However all units are plug-compatible. 0.50 (12.7) 0.18 (4.6) 0.015 minimum clearance between standoffs and highest component 2.00 (50.8) 0.300 (7.62) 0.300 (7.62) 1 4 0.15 0.900 (3.81) (22.9) 2 3 Bottom view Pin 8 www.murata-ps.com INPUT/OUTPUT CONNECTIONS Pin Function P32 1 −Input 2 On/Off Control 3 +Input 4 −Output 5 −Sense 6 Output Trim 7 +Sense 8 +Output Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 6 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters APPLICATION NOTES Input Fusing Certain applications and/or safety agencies may require fuses at the inputs of power conversion components. Fuses should also be used when there is the possibility of sustained input voltage reversal which is not current-limited. We recommend a time delay fuse installed in the ungrounded input supply line with a value which is approximately twice the maximum line current, calculated at the lowest input voltage. The installer must observe all relevant safety standards and regulations. For safety agency approvals, install the converter in compliance with the end-user safety standard, i.e. IEC/EN/UL 60950-1. Input Reverse-Polarity Protection If the input voltage polarity is reversed, an internal body diode will become forward biased and likely draw excessive current from the power source. If this source is not current-limited or the circuit appropriately fused, it could cause permanent damage to the converter. Please be sure to install a properlyrated external input fuse (see Specifications). Input Under-Voltage Shutdown and Start-Up Threshold Under normal start-up conditions, converters will not begin to regulate properly until the ramping-up input voltage exceeds and remains at the Start-Up Threshold Voltage (see Specifications). Once operating, converters will not turn off until the input voltage drops below the Under-Voltage Shutdown Limit. Subsequent restart will not occur until the input voltage rises again above the Start-Up Threshold. This built-in hysteresis prevents any unstable on/off operation at a single input voltage. Users should be aware however of input sources near the Under-Voltage Shutdown whose voltage decays as input current is consumed (such as capacitor inputs), the converter shuts off and then restarts as the external capacitor recharges. Such situations could oscillate. To prevent this, make sure the operating input voltage is well above the UV Shutdown voltage AT ALL TIMES. Start-Up Time Assuming that the output current is set at the rated maximum, the Vin to Vout Start-Up Time (see Specifications) is the time interval between the point when the ramping input voltage crosses the Start-Up Threshold and the fully loaded regulated output voltage enters and remains within its specified accuracy band. Actual measured times will vary with input source impedance, external input capacitance, input voltage slew rate and final value of the input voltage as it appears at the converter. Input Source Impedance These converters will operate to specifications without external components, assuming that the source voltage has very low impedance and reasonable input voltage regulation. Since real-world voltage sources have finite impedance, performance is improved by adding external filter components. Sometimes only a small ceramic capacitor is sufficient. Since it is difficult to totally characterize all applications, some experimentation may be needed. Note that external input capacitors must accept high speed switching currents. Because of the switching nature of DC/DC converters, the input of these converters must be driven from a source with both low AC impedance and adequate DC input regulation. Performance will degrade with increasing input inductance. Excessive input inductance may inhibit operation. The DC input regulation specifies that the input voltage, once operating, must never degrade below the Shut-Down Threshold under all load conditions. Be sure to use adequate trace sizes and mount components close to the converter. I/O Filtering, Input Ripple Current and Output Noise All models in this converter series are tested and specified for input reflected ripple current and output noise using designated external input/output components, circuits and layout as shown in the figures below. External input capacitors (Cin in the figure) serve primarily as energy storage elements, minimizing line voltage variations caused by transient IR drops in the input conductors. Users should select input capacitors for bulk capacitance (at appropriate frequencies), low ESR and high RMS ripple current ratings. In the figure below, the Cbus and Lbus components simulate a typical DC voltage bus. Your specific system configuration may require additional considerations. Please note that the values of Cin, Lbus and Cbus will vary according to the specific converter model. TO OSCILLOSCOPE VIN + – + – CURRENT PROBE 4 +INPUT LBUS CBUS CIN 1 −INPUT CIN = 33μF, ESR < 700mΩ @ 100kHz CBUS = 220μF, ESR < 100mΩ @ 100kHz LBUS = 12μH Figure 2. Measuring Input Ripple Current These converters include a soft start circuit to moderate the duty cycle of its PWM controller at power up, thereby limiting the input inrush current. In critical applications, output ripple and noise (also referred to as periodic and random deviations or PARD) may be reduced by adding filter elements such as multiple external capacitors. Be sure to calculate component temperature rise from reflected AC current dissipated inside capacitor ESR. The On/Off Remote Control interval from On command to Vout regulated assumes that the converter already has its input voltage stabilized above the Start-Up Threshold before the On command. The interval is measured from the On command until the output enters and remains within its specified accuracy band. The specification assumes that the output is fully loaded at maximum rated current. Similar conditions apply to the On to Vout regulated specification such as external load capacitance and soft start circuitry. In the figure, the two copper strips simulate real-world printed circuit impedances between the power supply and its load. In order to minimize circuit errors and standardize tests between units, scope measurements should be made using BNC connectors or the probe ground should not exceed one half inch and soldered directly to the fixture. www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 7 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters +SENSE +OUTPUT 6 COPPER STRIP 5 C1 −OUTPUT −SENSE Note that the temperatures are of the ambient airflow, not the converter itself which is obviously running at higher temperature than the outside air. Also note that very low flow rates (below about 25 LFM) are similar to “natural convection,” that is, not using fan-forced airflow. C2 SCOPE RLOAD 9 8 COPPER STRIP C1 = 0.1μF CERAMIC C2 = 10μF TANTALUM LOAD 2-3 INCHES (51-76mm) FROM MODULE Figure 3. Measuring Output Ripple and Noise (PARD) Floating Outputs Since these are isolated DC/DC converters, their outputs are “floating” with respect to their input. The essential feature of such isolation is ideal ZERO CURRENT FLOW between input and output. Real-world converters however do exhibit tiny leakage currents between input and output (see Specifications). These leakages consist of both an AC stray capacitance coupling component and a DC leakage resistance. When using the isolation feature, do not allow the isolation voltage to exceed specifications. Otherwise the converter may be damaged. Designers will normally use the negative output (-Output) as the ground return of the load circuit. You can however use the positive output (+Output) as the ground return to effectively reverse the output polarity. Minimum Output Loading Requirements All models regulate within specification and are stable under no load to full load conditions. Operation under no load might however slightly increase output ripple and noise. Thermal Shutdown To prevent many over temperature problems and damage, these converters include thermal shutdown circuitry. If environmental conditions cause the temperature of the DC/DC’s to rise above the Operating Temperature Range up to the shutdown temperature, an on-board electronic temperature sensor will power down the unit. When the temperature decreases below the turn-on threshold, the converter will automatically restart. There is a small amount of hysteresis to prevent rapid on/off cycling. The temperature sensor is typically located adjacent to the switching controller, approximately in the center of the unit. See the Performance and Functional Specifications. CAUTION: If you operate too close to the thermal limits, the converter may shut down suddenly without warning. Be sure to thoroughly test your application to avoid unplanned thermal shutdown. Temperature Derating Curves The graphs in the next section illustrate typical operation under a variety of conditions. The Derating curves show the maximum continuous ambient air temperature and decreasing maximum output current which is acceptable under increasing forced airflow measured in Linear Feet per Minute (“LFM”). Note that these are AVERAGE measurements. The converter will accept brief increases in current or reduced airflow as long as the average is not exceeded. www.murata-ps.com Murata Power Solutions makes Characterization measurements in a closed cycle wind tunnel with calibrated airflow. We use both thermocouples and an infrared camera system to observe thermal performance. As a practical matter, it is quite difficult to insert an anemometer to precisely measure airflow in most applications. Sometimes it is possible to estimate the effective airflow if you thoroughly understand the enclosure geometry, entry/exit orifice areas and the fan flowrate specifications. CAUTION: If you routinely or accidentally exceed these Derating guidelines, the converter may have an unplanned Over Temperature shut down. Also, these graphs are all collected at slightly above Sea Level altitude. Be sure to reduce the derating for higher density altitude. Output Overvoltage Protection This converter monitors its output voltage for an over-voltage condition. If the output exceeds OVP limits, the sensing circuit will power down the unit, and the output voltage will decrease. After a time-out period, the PWM will automatically attempt to restart, causing the output voltage to ramp up to its rated value. It is not necessary to power down and reset the converter for the automatic OVP-recovery restart. If the fault condition persists and the output voltage climbs to excessive levels, the OVP circuitry will initiate another shutdown cycle. This on/off cycling is referred to as “hiccup” mode. It safely tests full current rated output voltage without damaging the converter. Output Fusing The converter is extensively protected against current, voltage and temperature extremes. However your output application circuit may need additional protection. In the extremely unlikely event of output circuit failure, excessive voltage could be applied to your circuit. Consider using an appropriate fuse in series with the output. Output Current Limiting As soon as the output current increases to approximately 125% to 150% of its maximum rated value, the DC/DC converter will enter a current-limiting mode. The output voltage will decrease proportionally with increases in output current, thereby maintaining a somewhat constant power output. This is also commonly referred to as power limiting. Current limiting inception is defined as the point at which full power falls below the rated tolerance. See the Performance/Functional Specifications. Note particularly that the output current may briefly rise above its rated value in normal operation as long as the average output power is not exceeded. This enhances reliability and continued operation of your application. If the output current is too high, the converter will enter the short circuit condition. Output Short Circuit Condition When a converter is in current-limit mode, the output voltage will drop as the output current demand increases. If the output voltage drops too low (approximately 98% of nominal output voltage for most models), the magnetically Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 8 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters coupled voltage used to develop primary side voltages will also drop, thereby shutting down the PWM controller. Following a time-out period, the PWM will restart, causing the output voltage to begin ramping up to its appropriate value. If the short-circuit condition persists, another shutdown cycle will initiate. This rapid on/off cycling is called “hiccup mode”. The hiccup cycling reduces the average output current, thereby preventing excessive internal temperatures and/or component damage. A short circuit can be tolerated indefinitely. The “hiccup” system differs from older latching short circuit systems because you do not have to power down the converter to make it restart. The system will automatically restore operation as soon as the short circuit condition is removed. 1 Note: The Sense input and power Vout lines are internally connected through low value resistors to their respective polarities so that the converter can operate without external connection to the Sense. Nevertheless, if the Sense function is not used for remote regulation, the user should connect +Sense to +Vout and –Sense to –Vout at the converter pins. The remote Sense lines carry very little current. They are also capacitively coupled to the output lines and therefore are in the feedback control loop to regulate and stabilize the output. As such, they are not low impedance inputs and must be treated with care in PC board layouts. Sense lines on the PCB should run adjacent to DC signals, preferably Ground. In cables and discrete wiring, use twisted pair, shielded tubing or similar techniques. Any long, distributed wiring and/or significant inductance introduced into the Sense control loop can adversely affect overall system stability. If in doubt, test your applications by observing the converter’s output transient response during step loads. There should not be any appreciable ringing or oscillation. You may also adjust the output trim slightly to compensate for voltage loss in any external filter elements. Do not exceed maximum power ratings. Please observe Sense inputs tolerance to avoid improper operation: [Vout(+) −Vout(-)] − [Sense(+) −Sense(-)] ≤ 10% of Vout +OUTPUT +SENSE 6 I OUT Sense Current 3 ON/OFF CONTROL TRIM 7 LOAD Sense Return −SENSE 4 Remote Sense Input Use the Sense inputs with caution. Sense is normally connected at the load. Sense inputs compensate for output voltage inaccuracy delivered at the load. This is done by correcting IR voltage drops along the output wiring and the current carrying capacity of PC board etch. This output drop (the difference between Sense and Vout when measured at the converter) should not be allowed to exceed 0.5V. Consider using heavier wire if this drop is excessive. Sense inputs also improve the stability of the converter and load system by optimizing the control loop phase margin. −INPUT Contact and PCB resistance losses due to IR drops 5 8 I OUT Return +INPUT -OUTPUT 9 Contact and PCB resistance losses due to IR drops Figure 4. Remote Sense Circuit Configuration Trimming the Output Voltage The Trim input to the converter allows the user to adjust the output voltage over the rated trim range (please refer to the Specifications). In the trim equations and circuit diagrams that follow, trim adjustments use either a trimpot or a single fixed resistor connected between the Trim input and either the +Sense or –Sense terminals. (On some converters, an external user-supplied precision DC voltage may also be used for trimming). Trimming resistors should have a low temperature coefficient (±100 ppm/deg.C or less) and be mounted close to the converter. Keep leads short. If the trim function is not used, leave the trim unconnected. With no trim, the converter will exhibit its specified output voltage accuracy. There are two CAUTIONs to be aware of for the Trim input: CAUTION: To avoid unplanned power down cycles, do not exceed EITHER the maximum output voltage OR the maximum output power when setting the trim. Be particularly careful with a trimpot. If the output voltage is excessive, the OVP circuit may inadvertantly shut down the converter. If the maximum power is exceeded, the converter may enter current limiting. If the power is exceeded for an extended period, the converter may overheat and encounter overtemperature shut down. CAUTION: Be careful of external electrical noise. The Trim input is a senstive input to the converter’s feedback control loop. Excessive electrical noise may cause instability or oscillation. Keep external connections short to the Trim input. Use shielding if needed. Also consider adding a small value ceramic capacitor between the Trim and –Vout to bypass RF and electrical noise. Output overvoltage protection is monitored at the output voltage pin, not the Sense pin. Therefore excessive voltage differences between Vout and Sense together with trim adjustment of the output can cause the overvoltage protection circuit to activate and shut down the output. Power derating of the converter is based on the combination of maximum output current and the highest output voltage. Therefore the designer must insure: (Vout at pins) x (Iout) ≤ (Max. rated output power) www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 9 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Trim Equations Trim Down Connect trim resistor between trim pin and −Sense Trim Up Connect trim resistor between trim pin and +Sense RTrimDn (k Ω) = 5.11 − 10.22 RTrimUp (k Ω) = 5.11 × VNOM × (1+) − 5.11 − 10.22 1.225 × Where, = | (VNOM − VOUT) / VNOM | VNOM is the nominal, untrimmed output voltage. VOUT is the desired new output voltage. Do not exceed the specified trim range or maximum power ratings when adjusting trim. Use 1% precision resistors mounted close to the converter on short leads. Trim Circuits +OUTPUT –INPUT +VCC +SENSE ON/OFF CONTROL 3 TRIM ON/OFF CONTROL LOAD –SENSE +INPUT 1 –OUTPUT Figure 5. Trim Connections Using A Trimpot –INPUT Figure 7. Driving the On/Off Control Pin (suggested circuit) +OUTPUT +OUTPUT –INPUT +SENSE ON/OFF CONTROL +SENSE TRIM LOAD RTRIM UP ON/OFF CONTROL RTRIM DOWN TRIM LOAD –SENSE –SENSE +INPUT -INPUT +INPUT –OUTPUT Figure 6. Trim Connections To Increase Output Voltages –OUTPUT Figure 8. Trim Connections To Decrease Output Voltages Connect sense to its respective VOUT pin if sense is not used with a remote load. www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 10 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Remote On/Off Control On the input side, a remote On/Off Control can be ordered with either polarity. Positive: Standard models are enabled when the On/Off pin is left open or is pulled high to +Vin with respect to –Vin. An internal bias current causes the open pin to rise to approximately +15V. Some models will also turn on at lower intermediate voltages (see Specifications). Positive-polarity devices are disabled when the On/Off is grounded or brought to within a low voltage (see Specifications) with respect to –Vin. Negative: Optional negative-polarity devices are on (enabled) when the On/ Off is grounded or brought to within a low voltage (see Specifications) with respect to –Vin. The device is off (disabled) when the On/Off is left open or is pulled high to approximately +15V with respect to –Vin. Dynamic control of the On/Off function should be able to sink appropriate signal current when brought low and withstand appropriate voltage when brought high. Be aware too that there is a finite time in milliseconds (see Specifications) between the time of On/Off Control activation and stable, regulated output. This time will vary slightly with output load type and current and input conditions. www.murata-ps.com There are several CAUTIONs for the On/Off Control: CAUTION: While it is possible to control the On/Off with external logic if you carefully observe the voltage levels, the preferred circuit is either an open drain/open collector transistor, a switch or a relay (which can thereupon be controlled by logic) returned to negative Vin. CAUTION: Do not apply voltages to the On/Off pin when there is no input power voltage. Otherwise the converter may be permanently damaged. Output Capacitive Load These converters do not require external capacitance added to achieve rated specifications. Users should only consider adding capacitance to reduce switching noise and/or to handle spike current step loads. Install only enough capacitance to achieve noise objectives. Excess external capacitance may cause regulation problems, slower transient response and possible instability. Proper wiring of the Sense inputs will improve these factors under capacitive load. The maximum rated output capacitance and ESR specification is given for a capacitor installed immediately adjacent to the converter. Any extended output wiring or smaller wire gauge or less ground plane may tolerate somewhat higher capacitance. Also, capacitors with higher ESR may use a larger capacitance. Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 11 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Typical Performance Curves UCE-1.5/20-D48 Efficiency vs Line Voltage & Load Current @ 25ºC UCE-1.5/20-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) 90 20 Vin = 75V 80 Efficiency (%) Output Current (A) 85 Vin = 48V Vin = 36V 75 18 400 LFM 300 LFM 200 LFM 100 LFM 16 14 12 70 10 65 30 40 50 60 70 80 Ambient Temperature (ºC) 60 3 6 9 12 15 18 Load Current (A) UCE-1.8/30-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) 35 30 Vin = 75V Output Current (A) Efficiency (%) UCE-1.8/30-D48 Efficiency vs Line Voltage & Load Current @ 25ºC 95 90 85 80 75 70 65 60 55 50 45 40 Vin = 48V Vin = 36V 25 400 LFM 300 LFM 200 LFM 100 LFM 20 15 10 5 0 3 5 7 9 11 13 15 17 19 21 23 25 27 30 35 40 29 45 50 55 60 65 70 75 80 Ambient Temperature (ºC) Load Current (A) UCE-2.5/20-D48 Maximum Current Temperature Derating (Vin = 48V, with baseplate, longitudinal airflow at sea level) UCE-2.5/20-D48 Efficiency vs Line Voltage & Load Current @ 25ºC 20 95 Output Current (A) 18 Efficiency (%) 90 Vin = 75V Vin = 48V Vin = 36V 85 80 300 LFM 200 LFM 100 LFM Natural Convection 16 14 12 10 30 75 40 50 60 70 80 Ambient Temperature (ºC) 70 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Load Current (A) www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 12 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Typical Performance Curves UCE-3.3/15-D48 Efficiency Vs. Line Voltage & Load Current @ +25ºC UCE-3.3/15-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) 95 16 14 12 Output Current (A) Efficiency (%) 90 Vin = 75V Vin = 48V Vin = 36V 85 80 10 8 400 LFM 300 LFM 200 LFM 100 LFM 6 4 2 75 0 30 40 50 60 70 80 70 3 4 5 6 7 8 9 10 11 12 13 14 Ambient Temperature (ºC) 15 Load Current (A) UCE-3.3/30-D48 Efficiency vs Line Voltage & Load Current @ 25ºC UCE-3.3/30-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) 95 90 Efficiency (%) 80 75 35 Vin = 75V Vin = 48V Vin = 36V 30 Output Current (A) 85 70 65 60 55 400 LFM 300 LFM 200 LFM 20 15 100 LFM 10 50 45 40 25 5 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 0 30 35 40 45 50 55 60 65 70 75 80 Load Current (A) Ambient Temperature (ºC) www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 13 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Typical Performance Curves UCE-5/10-D48 Maximum Current Temperature Derating at Sea Level (Vin = 48V, transverse airflow, no baseplate) 3.5 11 3 10 2.5 2 Vin = 75V Vin = 48V Vin = 36V 1.5 1 Power Dissipation (Vin = 48V) 1 2 3 4 5 6 7 8 9 Output Current (A) 100 98 96 94 92 90 88 86 84 82 80 78 76 74 72 70 Power Dissipation (Watts) Efficiency (%) UCE-5/10-D48 Efficiency Vs. Line Voltage & Load Current @ +25ºC Natural Convection 100 LFM 200 LFM 300 LFM 400 LFM 7 6 5 4 0.5 9 8 30 35 40 45 50 55 60 65 70 75 80 85 80 85 Ambient Temperature (ºC) 0 10 Load Current (A) UCE-5/20-D48 Maximum Current Temperature Derating at Sea Level (Vin = 48V, transverse airflow, no baseplate) UCE-5/20-D48 Efficiency Vs. Line Voltage & Load Current @ +25ºC 96 16 94 14 92 12 10 Vin = 75V Vin = 48V Vin = 36V 88 86 8 6 4 84 Power Dissipation (Vin = 48V) 82 2 0 80 3 4 5 6 7 8 9 Output Current (A) 90 20 Power Dissipation (Watts) Efficiency (%) 25 15 Natural Convection 100 LFM 200 LFM 300 LFM 400 LFM 10 5 0 30 35 40 45 50 55 60 65 70 75 Ambient Temperature (ºC) 10 11 12 13 14 15 16 17 18 19 20 Load Current (A) www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 14 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Typical Performance Curves UCE-12/4.2-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) UCE-12/4.2-D48 Efficiency Vs. Line Voltage & Load Current @ +25ºC 95 4.25 90 4 Vin = 75V Vin = 48V Vin = 36V 80 75 Output Current (A) Efficiency (%) 85 70 200 to 400 LFM 100 LFM 3.75 3.5 3.25 65 60 0.6 1.2 1.8 2.4 3.0 3.6 3 4.2 30 40 Load Current (A) 50 60 70 80 Ambient Temperature (ºC) UCE-12/8.3-D48 Efficiency vs Line Voltage & Load Current @ 25ºC 95 5 90 4 UCE-12/8.3-D48 Maximum Current Temperature Derating (Vin = 48V, no baseplate, longitudinal airflow at sea level) 9 80 3 2 Output Current (A) Vin = 75V Vin = 48V Vin = 36V 85 7 1 75 6 400 LFM 300 LFM 200 LFM 100 LFM 5 4 3 2 1 0 30 0 70 3 4 5 6 7 35 40 45 50 55 60 65 70 75 80 85 75 80 85 8 Ambient Temperature (ºC) Load Current (A) UCE-12/8.3-D48 Maximum Current Temperature Derating at sea level (Vin = 48V, with baseplate, airflow is from -Vin to +Vin) 9 8 7 Output Current (Amps) Efficiency (%) 8 400 LFM 300 LFM 200 LFM 100 LFM 6 5 4 3 2 1 0 30 35 40 45 50 55 60 65 70 Ambient Temperature (ºC) www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 15 of 16 UCE Series Isolated, High-Density, Eighth-Brick 100W DC/DC Converters Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 www.murata-ps.com email: [email protected] ISO 9001 REGISTERED 03/27/09 Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. © 2008 Murata Power Solutions, Inc. www.murata-ps.com USA: Mansfield (MA), Tel: (508) 339-3000, email: [email protected] Canada: Toronto, Tel: (866) 740-1232, email: [email protected] UK: Milton Keynes, Tel: +44 (0)1908 615232, email: [email protected] France: Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: [email protected] Germany: München, Tel: +49 (0)89-544334-0, email: [email protected] Japan: Tokyo, Tel: 3-3779-1031, email: [email protected] Osaka, Tel: 6-6354-2025, email: [email protected] China: Shanghai, Tel: +86 215 027 3678, email: [email protected] Guangzhou, Tel: +86 208 221 8066, email: [email protected] Singapore: Parkway Centre, Tel: +65 6348 9096, email: [email protected] Technical enquiries email: [email protected], tel: +1 508 339 3000 MDC_UCE.A18 Page 16 of 16