AVO50 Series DC/DC Converter TRN AVO50 Series DC/DC Converter Technical Reference Notes Industry Standard Eighth Brick: 36~75V Input, 1.2V~12V Single Output Features * * * * * Industry standard eighth brick: 2.28" x 0.9'' x 0.35'' Options * * Choice of positive logic or negative logic for CNT function Choice of short pins or long pins Description * * * * * * * * * * * Delivers up to 25A output current Industry standard eighth brick foot print 57.9mm x 22.9mm x 8.9mm (2.28" x 0.9" x 0.35") Basic isolation Ultra high efficiency: 91% at 5V full load (Vin = 48Vdc) Improved thermal performance: full load at 55C at 1m/s (200LFM) for 5Vo High power density Low output noise 2:1 wide input voltage of 36V-75V CNT function Remote sense Trim function: +10%/-20% Input under-voltage lockout Output over-current protection Output over-voltage protection Over-temperature protection RoHS compliant The AVO50 series DC/DC converter (for short, converter) is a new open frame DC/DC converter for optimum efficiency and power density. The converter provides up to 25A output current, which makes it an ideal choice for small space, high current and low voltage applications. The converter uses an industry standard eighth brick: 57.9mm x 22.9mm x 8.9mm (2.28" x 0.9" x 0.35") and standard pinout configuration, and provide CNT and trim functions. The converters can provide 1.2V to 12V single output. Outputs are isolated from inputs. The converter can achieve ultra high efficiency. For most applications, a heat sink is not required. TEL: (86) 755-86010808 BOM:31020684 www.emersonnetworkpower.com.cn DATE: 2008-07-17 1/34 REV1.2 AVO50 Series DC/DC Converter TRN Converter Numbering AVO 50 - 48 S 1V5 P - 4 Pin length: Omit for 5.8 mm 0.5mm (0.228in. 0.02in.) -4---4.8 mm 0.5mm (0.189in. 0.02in.) -6---3.80mm 0.25mm(0.150in. 0.010in.) -8---2.80mm 0.25mm(0.110in. 0.010in.) CNT logic, P---positive logic control, default is negative logic control Output rated voltage: 1V2--1.2V, 1V5--1.5V, 1V8--1.8V, 2V5--2.5V, 3V3--3.3V, 05--5V, 12--12V Output number: S ---single output, D---dual output Input rated voltage Output rated power: Power digit based on maximum output power. The lower output is limited by its current Series name TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 2/34 AVO50 Series DC/DC Converter TRN Electrical Specifications Unless otherwise indicated, specifications apply over all operating input voltage and temperature conditions. Standard test condition on a single converter is as follows: Tc (board): 25 C +Vin: 48V 2% -Vin: return pin for +Vin CNT: connected to -Vin for negative logic open for positive logic +Vout: -Vout: +Sense: -Sense: Trim(Vadj): connected to load connected to load (return) connected to +Vout connect edto -Vout open Input Specifications Parameter Operating Input Voltage Maximum Input Current Symbol Min Typ Max Unit VI 36 48 75 VDC II,max - - 2.5 A II - - 20 mAp-p - 50 60 - dB (VI = 0 to VI,max, Io = Io,max) Input Reflected-ripple Current (5Hz to 20MHz, 12uH source impedance, TA = 25 C) Supply Voltage Rejection (1kHz) CAUTION: The converters have no internal fuse. An input line fuse must always be used. TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 3/34 AVO50 Series DC/DC Converter TRN Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operational sections of the IPS. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Parameter Device Symbol Min Typ Max Unit All VI 0 - 75 Vdc All VI, trans 0 - 100 Vdc All Ta -40 - 85 C Operating Board Temperature All Tc - - 100 C Storage Temperature All TSTG -55 - 125 C Operating Humidity All - - - 85 % All - 2000 Vdc Continuous Input Voltage Transient (100ms) Operating Ambient Temperature (See Thermal Consideration) Basic Input-Output Isolation (Conditions: 1mA for 60 sec, slew rate of 1500V/10sec) Output Power TEL: (86) 755-86010808 1.2V 24 1.5V 30 1.8V 36 2.5V Po,max 0 - 50 3.3V 49.5 5V 50 12V 50 www.emersonnetworkpower.com.cn W 4/34 AVO50 Series DC/DC Converter TRN Output Specifications Parameter Output Ripple and Noise Peak-to-Peak (5Hz to 20 MHz) (Across 1F @10V, X7R ceramic capacitor & 470F @10V LOW ESR Aluminum capacitor) External Load Capacitance Device Symbol Min Typ 1.2V 50 1.5V 55 1.8V 45 2.5V - - 50 3.3V 50 5V 55 12V 55 Max Unit - mVp-p 1.2V 10,000 1.5V 10,000 1.8V 10,000 2.5V - 220 470 10,000 3.3V 10,000 5V 5000 12V 1000 1.2V 1.18 1.2 1.22 1.5V 1.48 1.5 1.52 Output Voltage Setpoint 1.8V 1.77 1.8 1.83 (VI = VI,min to VI,max: Io = Io,max; Ta = 25 C ) 2.5V 2.46 2.5 2.54 3.3V 3.25 3.3 3.35 5V 4.95 5 5.05 12V 11.85 12 12.15 TEL: (86) 755-86010808 Vo,set www.emersonnetworkpower.com.cn F Vdc 5/34 AVO50 Series DC/DC Converter TRN Parameter Line (Vi,min to Vi,max) Output Regulation Load (Io,min to Io,max) Temperature (Tc = -40C to +100C) Rated Output Current Device Symbol Min Typ 1.2V 1 1.5V 1 1.8V 1 2.5V - - 1 3.3V 1 5V 4 12V 9 1.2V 1 1.5V 1 1.8V 1 2.5V - - 1 3.3V 1 5V 5 12V 5 All - - - Max Unit - mV - mV 0.02 %Vo/C 1.2V, 20 1.5V 20 1.8V 20 2.5V Io 0 - 20 3.3V 15 5V 10 12V 4.2 1.2V 22 28 1.5V 22 28 Output Current-limit Inception 1.8V 22 28 (Hiccup) 3.3V 16.5 21 5V 11 14 12V 4.6 7.0 TEL: (86) 755-86010808 2.5V Io 22 - www.emersonnetworkpower.com.cn 28 A A 6/34 AVO50 Series DC/DC Converter TRN Parameter Device Symbol Min Typ 1.2V 88 1.5V 87 Efficiency 1.8V 89 (VI = VI,nom; 100%Io,max ; TA = 25C) 2.5V - - 91 5V 91 12V 91 1.2V 86 1.5V 86 Efficiency 1.8V 88 (VI = VI,nom ; 50%Io,max ; TA = 25C) 2.5V - Unit - % - % 90 3.3V - Max 88 3.3V 91 5V 90 12V 89 Output Specifications (Cont) Parameter Device Load Change from Io = 50% to 75% to 50% Io,max Min Typ 1.2V 60 1.5V 60 1.8V 40 2.5V - - 50 3.3V 95 5V 100 12V 150 1.2V 300 1.5V 110 Peak Deviation Settling Time 1.8V 105 (to Vo,nom) 3.3V 60 5V 120 12V 120 Dynamic Response (Io/t = 1A/10s, VI = VI,nom; Ta = 25C) Symbol TEL: (86) 755-86010808 2.5V - - www.emersonnetworkpower.com.cn 60 Max Unit - mV - sec 7/34 AVO50 Series DC/DC Converter TRN Parameter Dynamic Response (Io/t = 1A/1s; VI = VI,nom; Ta = 25C, additional 220F load capacitor) Device Load Change from Io = 50% to 75% to 50% Io,max Peak Settling Vo,nom) Deviation Time (to Turn-On Time (Io = Io,max ; Vo within 1%) Output Voltage Overshoot Symbol Min Typ 1.2V 130 1.5V 130 1.8V 110 2.5V - 150 3.3V 130 5V 130 12V 180 1.2V 300 1.5V 100 1.8V 110 2.5V - 130 3.3V 80 5V 130 12V 300 Max Unit - mv - sec 20 msec All - - - All - - 0 %Vo All - 310 kHz (Io = Io,max ; TA = 25C) Switching Frequency TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 8/34 AVO50 Series DC/DC Converter TRN Feature Specifications Parameter Device Symbo l Min Typ Max Unit Logic Low All -0.7 - 1.2 V Logic High All 3.5 - 12 V Enable pin current Logic Low All - - 1.0 mA (leakage current, @10V) Logic High All - - - A 80 110 %Vo 1.2V 1.4 2.0 1.5V 1.8 2.5 1.8V 2.2 3.0 Enable pin voltage Output Voltage Adjustment Range Output Over-voltage (Hiccup) Over-temperature Protection (Auto-recovery) All* 2.5V - Voclamp 3.0 - 3.8 V 3.3V 3.9 5.0 5V 6.0 7.5 12V 14.4 18 All 110 120 135 C Turn-on Point All - 31 34 36 V Turn-off Point All - 30 33 35 V Isolation Capacitance All - - 1000 - PF Isolation Resistance All - 10 - - M All - - 2,500,000 - Hours All - - - 30 g(oz.) Under-voltage Lockout Calculated MTBF (Io = Io,max ; Tc = 25C) Weight Output Voltage Adjustment Rang of 12V converter is 90% to 110%. TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 9/34 AVO50 Series DC/DC Converter TRN Characteristic Curves 90 90 80 80 Vin=36V 75 Vin=48V Vin=75V 70 0 2 4 6 8 75 Efficiency (%) Effiency(%) 85 85 70 65 36V 48V 75V 60 10 12 14 16 18 20 55 0 Load(A) 5 10 15 20 25 Load (A) Fig.1 Typical efficiency of AVO50-48S1V2 Fig.2 Typical efficiency of AVO50-48S1V5 95 90 Effiency(%) Effiency(%) 90 85 80 75 85 80 Vin=36V 75 Vin=36V Vin=48V Vin=75V Vin=48V 70 70 Vin=75V 0 2 4 6 8 10 12 14 16 18 20 0 5 10 Load(A) Fig.3 Typical efficiency of AVO50-48S1V8 Fig.4 Typical efficiency of AVO50-48S2V5 95 90 Effiency(%) 90 Ef f iciency(%) 20 Load(A) 95 85 80 2 4 6 8 10 12 14 16 18 85 80 Vin=36V 75 36V 48V 75V 75 Vin=48V Vin=75V 70 20 0 Typical efficiency of AVO50-48S3V3 TEL: (86) 755-86010808 2 4 6 8 10 Load(A) Load (A) Fig.5 15 Fig.6 Typical efficiency of AVO50-48S05 www.emersonnetworkpower.com.cn 10/34 AVO50 Series DC/DC Converter TRN 95 90 Effiency(%) 85 80 75 70 Vin=36V Vin=48V 65 Vin=75V 60 0 0.5 1 1.5 2 2.5 3 3.5 4 Output current(A) 1.4 1.2 1.6 1 0.8 0.6 0.4 1.2 1.4 0.2 0 0 Fig.8 Typical efficiency of AVO50-48S12 5 10 15 20 Output Current (A) 25 30 Output voltage (V) Output Voltage (V) Fig.7 1 0.8 0.6 0.4 0.2 0 0 Typical output over-current of AVO50-48S1V2 Fig.9 5 10 15 20 25 Output current (A) 30 35 40 Typical output over-current of AVO50-48S1V5 Output Voltage (V) Output Voltage (V) 3 1.8 1.5 1.2 0.9 0.6 0.3 0 2 1.5 1 0.5 0 0 Fig.10 2.5 5 10 15 20 Output Current (A) 25 30 Typical output over-current of AVO50-48S1V8 TEL: (86) 755-86010808 0 Fig.11 5 10 15 20 Output Current (A) 25 30 Typical output over-current of AVO50-48S2V5 www.emersonnetworkpower.com.cn 11/34 3.5 6 3 5 Output Voltage (V) Output VoltageV AVO50 Series DC/DC Converter TRN 2.5 2 1.5 1 4 3 2 1 0.5 0 0 0 0 5 10 15 20 25 30 35 3 40 6 9 Output Current (A) 12 15 Output CurrentA Fig.12 Typical output over-current of AVO50-48S3V3 Fig.14 Fig.13 Typical output over-current of AVO50-48S05 Typical output over-current of AVO50-48S12 7 4 2 Vin=36V 1 Vin=48V Vin=75V 0 0 2 4 6 8 10 12 14 16 18 20 Power dissipation (W) Dissipation(W) 6 3 5 4 3 2 36V 48V 75V 1 0 0 Load(A) 5 10 15 20 25 Load (A) Fig.15 Typical power dissipation of AVO50-48S1V2 TEL: (86) 755-86010808 Fig.16 Typical power dissipation of AVO50-48S1V5 www.emersonnetworkpower.com.cn 12/34 AVO50 Series DC/DC Converter TRN 4 Dissipation(W) Dissipation(W) 5 3 2 Vin=36V 1 Vin=48V Vin=75V 0 0 2 4 6 7 6 5 4 3 2 1 0 8 10 12 14 16 18 20 Vin=36V Vin=48V Vin=75V 0 5 Load(A) Fig.17 15 20 Load(A) Typical power dissipation of AVO50-48S1V8 Fig.18 8 Typical power dissipation of AVO50-48S2V5 6 6 Dissipation(W) Pow er Dissipation (W) 10 4 2 36V 48V 75V 0 2 4 6 8 10 12 14 16 18 5 4 3 2 Vin=36V Vin=48V 1 Vin=75V 0 0 20 2 Typical power dissipation of AVO50-48S3V3 6 8 10 Load(A) Load (A) Fig.19 4 Fig.20 Typical power dissipation of AVO50-48S05 7 Dissipation(W) 6 5 4 3 2 Vin=36V Vin=48V 1 Vin=75V 0 0 Fig.21 TEL: (86) 755-86010808 0.5 1 1.5 2 2.5 3 Output current(A) 3.5 4 4.5 Typical power dissipation of AVO50-48S12 www.emersonnetworkpower.com.cn 13/34 AVO50 Series DC/DC Converter TRN Fig.22 AVO50-48S1V2 typical transient response fig.23 to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input (io/t = 0.1A/1s) Fig.24 to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input TEL: (86) 755-86010808 to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) AVO50-48S1V5 typical transient response Fig.25 (io/t = 1A/1s) AVO50-48s1V2 typical transient response AVO50-48S1V5 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (io/t = 1A/1s) www.emersonnetworkpower.com.cn 14/34 AVO50 Series DC/DC Converter TRN Fig.26 AVO50-48S1V5 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input Fig.27 to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (io/t = 0.1A/1s) Fig.28 AVO50-48S1V5 typical transient response (io/t = 0.1A/1s) AVO50-48S1V5 typical transient response Fig.29 AVO50-48S1V5 typical transient response to step decrease in load from 50% to 25% to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input (Io/t = 1A/1s) TEL: (86) 755-86010808 (Io/t = 1A/1s) www.emersonnetworkpower.com.cn 15/34 AVO50 Series DC/DC Converter TRN Fig.30 AVO50-48S1V8 typical transient response Fig. 31 to step decrease in load from 50% to 25% to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) Fig.32 (Io/t = 0.1A/1s) AVO50-48S1V8 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) TEL: (86) 755-86010808 AVO50-48S1V8 typical transient response Fig.33 AVO50-48S1V8 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) www.emersonnetworkpower.com.cn 16/34 AVO50 Series DC/DC Converter TRN Fig.34 AVO505-48S2V5 typical transient response Fig. 35 to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) Fig.36 (Io/t = 0.1A/1s) AVO50-48S2V5 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) TEL: (86) 755-86010808 AVO50-48S2V5 typical transient response Fig.37 AVO50-48S2V5 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) www.emersonnetworkpower.com.cn 17/34 AVO50 Series DC/DC Converter TRN Fig.38 AVO50-48S3V3 typical transient response Fig. 39 to step decrease in load from 50% to 25% to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) Fig.40 AVO50-48S3V3 typical transient response (Io/t = 0.1A/1s) AVO50-48S3V3 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) TEL: (86) 755-86010808 Fig.41 AVO50-48S3V3 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) www.emersonnetworkpower.com.cn 18/34 AVO50 Series DC/DC Converter TRN Fig.42 Fig.44 AVO50-48S05 typical transient response Fig. 43 AVO50-48S05 typical transient response to step decrease in load from 50% to 25% to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) (Io/t = 0.1A/1s) AVO50-48S05 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input Fig.45 AVO50-48S05 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 1A/1s) Fig.46 (Io/t = 1A/1s) AVO50-48S12 typical transient response to step decrease in load from 50% to 25% of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) TEL: (86) 755-86010808 Fig. 47 AVO50-48S12 typical transient response to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input (Io/t = 0.1A/1s) www.emersonnetworkpower.com.cn 19/34 AVO50 Series DC/DC Converter TRN Fig.48 AVO50-48S12 typical transient response Fig.49 AVO50-48S12 typical transient response to step decrease in load from 50% to 25% to step increase in load from 50% to 75% of full load, room temperature, 48Vdc input of full load, room temperature, 48Vdc input (Io/t = 1A/1s) (Io/t = 1A/1s) Fig.50 Typical output ripple voltage of AVO50-48S1V2 room temperature, Io = Io,max room temperature, Io = Io,max Fig.52 Typical output ripple voltage of AVO50-48S1V8 room temperature, Io = Io,max TEL: (86) 755-86010808 Fig.51 Typical output ripple voltage of AVO50-48S1V5 Fig.53 Typical output ripple voltage of AVO50-48S2V5 room temperature, Io = Io,max www.emersonnetworkpower.com.cn 20/34 AVO50 Series DC/DC Converter TRN Fig.54 Typical output ripple voltage of AVO50-48S3V3 room temperature, Io = Io,max Fig.55 Typical output ripple voltage of AVO50-48S05 room temperature, Io = Io,max Fig.56 Typical output ripple voltage of AVO50-48S12 room temperature, Io = Io,max Fig.57 AVO50-48S1V2 typical start-up from power on TEL: (86) 755-86010808 Fig.58 AVO50-48S1V2 typical start-up from CNT on www.emersonnetworkpower.com.cn 21/34 AVO50 Series DC/DC Converter TRN Fig.59 AVO50-48S1V5 typical start-up from power on Fig.61 AVO50-48S1V8 typical start-up from power on Fig.63 AVO50-48S2V5 typical start-up from power on TEL: (86) 755-86010808 Fig.60 AVO50-48S1V5 typical start-up from CNT on Fig.62 AVO50-48S1V8 typical start-up from CNT on Fig.64 AVO50-48S2V5 typical start-up from CNT on www.emersonnetworkpower.com.cn 22/34 AVO50 Series DC/DC Converter TRN Fig.65 AVO50-48S3V3 typical start-up from power on Fig.67 AVO50-48S05 typical start-up from power on Fig.69 AVO50-48S12 typical start-up from power on TEL: (86) 755-86010808 Fig.66 AVO50-48S3V3 typical start-up from CNT on Fig.68 AVO50-48S05 typical start-up from CNT on Fig.70 AVO50-48S12 typical start-up from CNT on www.emersonnetworkpower.com.cn 23/34 AVO50 Series DC/DC Converter TRN Feature Description CNT Function The converter is equipped with a primary ON/OFF pin used to remotely turn the converter on or off via a system signal. Two CNT logic options are available. For the positive logic model a system logic low signal will turn the converter off. For the negative logic model a system logic high signal will turn the converter off. For negative logic models where no control signal will be used the ON/OFF pin should be connected directly to -Vin to ensure proper operation. For positive logic models where no control signal will be used the ON/OFF pin should be left unconnected. The following figure shows a few simple CNT circuits. Fig.71 CNT circuits Remote Sense The converter can remotely sense both lines of its output which moves the effective output voltage regulation point from the output terminals of the converter to the point of connection of the remote sense pins. This feature automatically adjusts the real output voltage of the converters in order to TEL: (86) 755-86010808 compensate for voltage drops in distribution and maintain a regulated voltage at the point of load. When the converter is supporting loads far away, or is used with undersized cabling, significant voltage drop can occur at the load. The best defense against such drops is to locate the load close to the converter and to ensure adequately sized cabling is used. When this is not possible, the converter can compensate for a drop of up to 10%Vo, through use of the sense leads. When used, the + Sense and - Sense leads should be connected from the converter to the point of load as shown in Fig.72, using twisted pair wire, or parallel pattern to reduce noise effect. The converter will then regulate its output voltage at the point where the leads are connected. Care should be taken not to reverse the sense leads. If reversed, the converter will trigger OVP protection. When not used, the +Sense lead must be connected with +Vo, and -Sense with -Vo. Although the output voltage can be increased by both the remote sense and by the trim, the maximum increase for the output voltage is not the sum of both. The maximum increase is the larger of either the remote sense or the trim. Note that at elevated output voltages the maximum power rating of the converter remains the same, and the output current capability will decrease correspondingly. Fig.72 Sense connections www.emersonnetworkpower.com.cn 24/34 AVO50 Series DC/DC Converter TRN Trim =(1.98-1.8) x 100/1.8=10 The +Vo output voltage of the converter can be trimmed with the trim pin provided. Applying a resistor to the trim pin through a voltage divider from the output will cause the +Vo output to increase by up to 10% or decrease by up to 20%. Trimming up by more than 10% of the nominal output may activate the OVP circuit or damage the converter. Trimming down more than 20% can cause the converter to regulate improperly. If the trim pin is not needed, it should be left open. R adj - up = 5.1 x 1.8 x (100 + 10 ) 510 - - 10.2( K) 1.225 x 10 10 R adj -up = 21.23( K) Trim down With an external resistor between the TRIM and -SENSE pins, the output voltage set point decreases (see Fig.74). Trim up With an external resistor connected between the TRIM and +SENSE pins, the output voltage set point increases (see Fig.73). Fig.74 Trim down circuit The following equation determines the required external-resistor value to obtain a percentage output voltage change of 1%. For Output Voltage: 1.2V ~ 12V Radj - down = Fig.73 Note: = (Vnom-Vo) x 100/Vnom Trim up circuit The following equation determines the required external-resistor value to obtain a percentage output voltage change of 1%. For Output Voltage: 1.5V ~ 12V 5.1 x V nom x (100 + % ) 510 R adj -up = - - 10.2( K) 1.225 x % % For Output Voltage: 1.2V 5.1 x V nom x (100 + % ) 510 R adj -up = - - 10.2( K) 0. 6 x % % Note: = (Vnom-Vo) x 100/Vnom Vtrim tolerance: < 2% Radj tolerance : 1% For example: to trim up the output of AVO75-48S1V8 to 1.98V: TEL: (86) 755-86010808 510 - 10.2( K) % Vtrim tolerance: <2% Radj tolerance: 1% For example: to trim down the output to 1.62V, =(1.8-1.62) x 100/1.8=10 Radj - down = 510 - 10.2( K) 10 Radj - down = 40.8( K) Although the output voltage can be increased by both the remote sense and by the trim, the maximum increase for the output voltage is not the sum of both. The maximum increase is the larger of either the remote sense or the trim. Note that at elevated output voltages the maximum power rating of the converter www.emersonnetworkpower.com.cn 25/34 AVO50 Series DC/DC Converter TRN remains the same, and the output current capability will decrease correspondingly. Minimum Load Requirements Fig.76 There is no minimum load requirement for the converter. Output Capacitance High output current transient rate (high di/dt) of change loads might require high values of output capacitance to supply the instantaneous energy requirement to the load. To minimize the output voltage transient drop during this transient, low Equivalent Series Resistance (ESR) capacitors may be required, since a high ESR will produce a correspondingly higher voltage drop during the current transient. When the load is sensitive to ripple and noise, an output filter can be added to minimize the effects. A simple output filter to reduce output ripple and noise can be made by connecting a capacitor C1 across the output as shown in Fig.75. The recommended value for the output capacitor C1 is 470F. Fig.75 Output ripple filter for a distant load Decoupling Noise on the power distribution system is not always created by the converter. High-speed analog or digital loads with dynamic power demands can cause noise to cross the power inductor back onto the input lines. Noise can be reduced by decoupling the load. In most cases, connecting a 10F tantalum or ceramic capacitor in parallel with a 0.1F ceramic capacitor across the load will decouple it. The capacitors should be connected as close to the load as possible. Ground Loops Ground loops occur when different circuits are given multiple paths to common or earth ground, as shown in Fig.77. Multiple ground points can have slightly different potentials and cause current flow through the circuit from one point to another. This can result in additional noise in all the circuits. To eliminate the problem, circuits should be designed with a single ground connection as shown in Fig.78. Output ripple filter Extra care should be taken when long leads or traces are used to provide power to the load. Long lead lengths increase the chance for noise to appear on the lines. Under these conditions C1 can be added across the load, with a 1F ceramic capacitor C2 in parallel generally as shown in Fig.76. +Vo Load Load -Vo RLine RLine RLine Ground R Loop Fig.77 TEL: (86) 755-86010808 RLine RLine Ground loops www.emersonnetworkpower.com.cn 26/34 AVO50 Series DC/DC Converter TRN +Vo RLine Load -Vo over-temperature condition is removed, the converter will automatically restart. RLine RLine Load RLine Design Consideration RLine Typical Application Fig.78 Single point ground F1 Output Over-current Protection +VIN Cin The converter feature foldback current limiting as part of their Over-current Protection (OCP) circuits. When output current exceeds 110 to 140% of rated current, such as during a short circuit condition, the converter will work on intermittent mode, also can tolerate short circuit conditions indefinitely. When the over-current condition is removed, the converter will automatically restart. Output Over-Voltage Protection The output over-voltage protection consists of circuitry that monitors the voltage on the output terminals. If the voltage on the output terminals exceeds the over voltage protection threshold, then the converter will work on intermittent mode. When the over-voltage condition is removed, the converter will automatically restart. The protection mechanism is such that the converter can continue in this condition until the fault is cleared. Over-Temperature Protection The converter features an over-temperature protection circuit to safeguard against thermal damage. The converter will work on intermittent mode when the maximum device reference temperature is exceeded. When the TEL: (86) 755-86010808 +VOUT +SENSE Vin CNT1 TRM S1 Co1 Co2 LOAD -SENSE -VIN Fig.79 -VOUT Typical application F1: Fuse. Use external fuse with a rating of 5A (fast blow type) for each converter. Cin: Recommended input capacitor. Use 47F/100V high frequency low ESR electrolytic type capacitor. Co1: Recommended capacitor 1F /10V ceramic Co2: Recommended output capacitor Use 470F/10V high frequency low ESR electrolytic type capacitor. If Ta<-5 C, use 220F tantalum capacitor parallel with a 470F/ 10V high frequency low ESR electrolytic capacitor. Note: The converter cannot be used in parallel mode directly! Fusing The converter has no internal fuse. An external fuse must always be employed! To meet international safety requirements, a 250 Volt rated fuse should be used. If one of the input lines is connected to chassis ground, then the fuse must be placed in the other input line. Standard safety agency regulations require input fusing. Recommended fuse ratings is 5A. Note: the fuse is fast blow type. www.emersonnetworkpower.com.cn 27/34 AVO50 Series DC/DC Converter TRN Input Reverse Voltage Protection Under installation and cabling conditions where reverse polarity across the input may occur, reverse polarity protection is recommended. Protection can easily be provided as shown in Fig.80. In both cases the diode used is rated for 10A/100V. Placing the diode across the inputs rather than in-line with the input offers an TEL: (86) 755-86010808 advantage in that the diode only conducts in a reverse polarity condition, which increases circuit efficiency and thermal performance. Fig.80 Reverse polarity protection circuit www.emersonnetworkpower.com.cn 28/34 AVO50 Series DC/DC Converter TRN a filter designed to reduce EMI effects. The converter can meet EN55022 CLASSA. EMC For conditions where EMI is a concern, a different input filter can be used. Fig.81 shows +Vin +Vout CY3 * CY1 CY7 U Vin+ L1 CX1 CY9 CY5 Vout+ +Sense * CNT Cout1 Cout2 Trim Cin1 CY2 CX2 CY4 -Sense CY8 Vin- Vout- -Vin CY10 CY6 -Vout Fig.81 EMI reduction filter Recommended values: Component Value/Rating CY1, CY2, CY5, CY6 4700PF/250VAC CX1 2.2/100V CY7, CY8, CY9, CY10 1000PF/250VAC CY3, CY4 0.47 Cin1 47/100V CX2 1u/100V Cout1 470/10V (low ESR capacitor) Cout2 1/10V L1 1.8mH Safety Consideration For safety-agency approval of the system in which the converter is used, the converter must TEL: (86) 755-86010808 be installed in compliance with the spacing and separation requirements of the end-use safety agency standard, i.e., UL1950, CSA C22.2 No. 950-95, and EN60950. The input-to-output isolation is a basic insulation. The converter should be installed in end-use equipment, in compliance with the requirements of the ultimate application, and is intended to be supplied by an isolated secondary circuit. When the supply to the converter meets all the requirements for SELV (<60Vdc), the output is considered to remain within SELV limits (level 3). If connected to a 60Vdc power system, double or reinforced insulation must be provided in the converter that isolates the input from any hazardous voltages, including the AC mains. One input pin and one output pin are to be grounded or both the input and output pins are to be kept floating. Single fault testing in the converter must be performed in combination with the converter to demonstrate that the output meets the requirement for SELV. The input pins of the converter are not operator accessible. www.emersonnetworkpower.com.cn 29/34 AVO50 Series DC/DC Converter TRN Note: Do not ground either of the input pins of the converter, without grounding one of the output pins. This may allow a non-SELV voltage to appear between the output pin and ground. Note: To comply with the published safety standards, the following must be observed when using this built-in converter. 1. The converter is intended for use as a component part of other equipment. When installing the converter and marking input and output connections, the relevant safety standards e.g. UL 60950-1; IEC 60950-1/VDE 0805;EN60950-1; CAN/CSA-22.2NO.60950-1-03 must be complied with, especially the requirements for creepage distances, clearances and distance through insulation between primary and earth or primary and secondary. 2. The output power taken from the built-in converter must not exceed the rating given on the converter. 3. The converter is not intended to be repaired by service personnel in case of failure or component defect. 4. The maximum ambient temperature around the converter must not exceed 55C. 5. An external forced air cooling (CFM: 80.2, Speed: 1m/s, distance from the converter: 20cm) shall be used for converter operates with full load and ambient up to 55C. 6. The converter has no in-line fuse. For safety purpose, a fast acting UL listed fuse or UL recognized fuse rated 5A/250V needs to be connected to the input side as external protection. TEL: (86) 755-86010808 Thermal Consideration Thermal management is an important part of the system design. The converter has ultra high efficiency at full load, and the converter exhibit good performance during pro-longed exposure to high temperatures. However, to ensure proper and reliable operation, sufficient cooling of the converter and power derating is needed over the entire temperature range of the converter. Considerations includes ambient temperature, airflow and converter power derating. Measuring thermal reference point of the converter as the method shown in Fig.82 can verify the proper cooling. Thermistor Thermocouple location Notice: The thermocouple must not touch the pads of the thermistor Fig.82 Thermocouple Temperature measurement location Converter Derating With 48V input, 55C ambient temperature, and 200LFM airflow, the converter is rated for full power. For operation above ambient temperature of 55C, the output power must be derated as shown in Fig.83 to Fig.89,. Meantime, airflow at least 200LFM over the converter must be provided to make the converter working properly. It is recommended that the temperature of the thermal reference point be measured using a thermocouple. Temperature on the PCB at the thermocouple location shown in Fig. 82 should www.emersonnetworkpower.com.cn 30/34 AVO50 Series DC/DC Converter TRN 20 Output Current Io (A) not exceed 125C in order to operate inside the derating curves as shown Fig. 83 to Fig.89. The use of output power derating curve is shown in the following example. Example What is the minimum airflow necessary for AVO50-48S3V3 operating at VI = 48V, an output current of 20A, and a maximum ambient temperature of 55C? Solution Given: VI = 48V, Io = 20A, Ta = 55C Determine airflow (v) (use Fig.83 to 89): v = 1m/sec. (200ft./min.) 15 2m/s 1.5m/s 10 1m/s 0.5m/s 5 0m/s 0 25 40 55 70 TEMPERATURE, Ta ( ) 85 Fig.85 AVO50-48S1V8 output power derating Airflow direction from -VIN to +VIN; VIN = 48V 20 15 Output Current Io (A) Output Current Io (A) 20 2m/s 1.5m/s 10 1m/s 0.5m/s 5 0m/s 2m/s 12 1.5m/s 8 1m/s 0.5m/s 4 0m/s 0 0 25 16 40 55 70 TEMPERATURE, Ta ( ) 25 85 40 55 70 TEMPERATURE, Ta ( ) 85 Fig.86 AVO50-48S2V5 output power derating Fig.83 AVO50-48S1V2 output power derating Airflow direction from -VIN to +VIN; VIN = 48V Airflow direction from -VIN to +VIN; VIN = 48V 15 15 Output Current Io (A) Output Current Io (A) 20 2m/s 1.5m/s 10 1m/s 0.5m/s 5 0m/s 12 2m/s 9 1.5m/s 1m/s 6 0.5m/s 3 0m/s 0 0 25 25 40 55 70 TEMPERATURE, Ta ( ) 85 40 55 70 TEMPERATURE, Ta ( ) 85 Fig.87 AVO50-48S3V3 output power derating Fig.84 AVO50-48S1V5 output power derating Airflow direction from -VIN to +VIN; VIN = 48V Airflow direction from -VIN to +VIN; VIN = 48V TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 31/34 AVO50 Series DC/DC Converter TRN Mechanical Considerations Output Current Io (A) 10 8 2m/s 6 1.5m/s Installation 1m/s 4 0.5m/s 2 0m/s 0 25 40 55 70 TEMPERATURE, Ta ( ) 85 Fig.88 AVO50-48S05 output power derating Output Current Io (A) Airflow direction from -VIN to +VIN; VIN = 48V 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 Soldering 2m/s 1.5m/s 1m/s 0.5m/s 0m/s 25 Although the converters can be mounted in any orientation, free air flowing must be taken. Normally power components are always put at the end of the airflow path or have the separate airflow paths. This can keep other system equipment cooler and increase component life spans. 40 55 70 TEMPERATURE, Ta ( ) 85 Fig.89 AVO50-48S12 output power derating Airflow direction from -VIN to +VIN; VIN = 48V MTBF The converter is compatible with standard wave soldering techniques. When wave soldering, the converter pins should be preheated for 20~30 seconds at 110C, and wave soldered at 260C for less than 10 seconds. When hand soldering, the iron temperature should be maintained at 425C and applied to the converter pins for less than 5 seconds. Longer exposure can cause internal damage to the converter. Cleaning can be performed with cleaning solvent IPA or with water. The MTBF, calculated in accordance with Bellcore TR-NWT-000332, is 2,500,000 hours. Obtaining this MTBF in practice is entirely possible. If the board temperature is expected to exceed +25C, then we also advise an oriented for the best possible cooling in the air stream. Emerson can supply replacements for converters from other manufacturers, or offer custom solutions. Please contact the factory for details. TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 32/34 AVO50 Series DC/DC Converter TRN Mechanical Chart (Top & pin side view) 57.9[2.28] 7.62[0.300] 15.24[0.600] 22.9[0.90] 1 4 5 TOP VIEW 2 6 7 3 8 15.24[0.600] 50.80[2.000] 8.9[0.35] 1.0 0.10 See Note 2 L 1.5 0.10 See note 3 2.0 0.1 Pin Length Option 8.9[0.35] Device Code Suffix TOLERANCES: XXmm=+/-0.5mm X.XXmm=+/-0.25mm L -4 4.8mm+/-0.5mm -6 3.8mm+/-0.5mm -8 2.8mm+/-0.25mm NONE 5.8mm+/-0.5mm Notes: 1. Un-dimensioned components are for visual reference only. 2. Pins 1~3, 5~7 are 1.0mm diameter with 2.0mm diameter standoff shoulders. 3. Pin 4 and pin 8 are 1.5mm diameter with no standoff shoulders. Pin No. Function Pin No. Function 1 +Vin 4 +Vo 2 CNT 5 +Sense 3 -Vin 6 Trim 7 -Sense 8 -Vo TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 33/34 AVO50 Series DC/DC Converter TRN Ordering Information Input Voltage (V) Output Voltage (V) Output Current (A) Ripple and Noise (mV pp) AVO50-48S1V2 36~75 1.2 20 0 86 AVO50-48S1V5 36~75 1.5 20 0 88 AVO50-48S1V8 36~75 1.8 20 0 88.5 AVO50-48S2V5 36~75 2.5 20 60 89.5 AVO50-48S3V3 36~75 3.3 15 0 91 AVO50-48S05 36~75 5 10 0 91 AVO50-48S12 36~75 12 4.2 90 91 Model Number Efficiency (%) Typ. Typ. Pb Hg Cd Cr6 PBB PBDE SJ/T-11363-2006 x SJ/T-11363-2006 1 2 3 AVO50 TEL: (86) 755-86010808 www.emersonnetworkpower.com.cn 34/34 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Emerson Network Power: AVO50-48S1V5-4 AVO50-48S1V2-4 AVO50-48S2V5P-4 AVO50-48S12-6L AVO50-48S1V8-4 AVO50-48S05-4 AVO50-48S1V8P-4 AVO50-48S1V2P-4 AVO50-48S12P-4 AVO50-48S2V5-4 AVO50-48S1V5P-4