rev. page date page date description: half-brick dc-dc converter 1 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W features 99-150w isolated output efficiency to 90% rohs compliant 4:1 input range regulated output continuous short circuit protection remote on/off over-voltage/current protection over-temperature shutdown industry standard ? brick size description the VHB150W series of dc-dc converters are designed for high reliability applications, featuring over-temperature protection, and over-current protection. the wide 4:1 input range (9-36v or 18- 75v) is very useful to stabilize an input source like batteries in various discharging and charging conditions. additionally, high efficiency, fast response, tight regulations, remote sense and remote on/off control make these converters very useful in many applications. model input voltage output output input current efficiency nominal range voltage current 1 no load 2 full load 2 typ. 3 (v dc) (v dc) (v dc) (a) (ma) (ma) (%) VHB150W-q24-s3r3 24 9.0~36.0 3.3 30 200 4741 85 VHB150W-q24-s5 24 9.0~36.0 5 30 200 7022 87 VHB150W-q24-s12 24 9.0~36.0 12 12.5 100 6944 88 VHB150W-q24-s15 24 9.0~36.0 15 10 100 6944 88 VHB150W-q24-s24 24 9.0~36.0 24 6.5 100 7022 88 VHB150W-q48-s3r3 48 18.0~75.0 3.3 30 100 2371 87 VHB150W-q48-s5 48 18.0~75.0 5 30 100 3511 89 VHB150W-q48-s12 48 18.0~75.0 12 12.5 50 3472 90 VHB150W-q48-s15 48 18.0~75.0 15 10 50 3472 90 VHB150W-q48-s24 48 18.0~75.0 24 6.5 50 3511 89 notes: 1. see output derating (page 4) 2. input currents are measured at nominal input voltage 3. efficiency is measured at nominal line, full load *v-infinity reserves the right to make changes to its products or to discontinue any product or service without notice, and to advise customers to verify the most up-to- date product information before placing orders. v-infinity assumes no liability or responsibility for customer?s applications u sing v-infinity products other than repair or replacing (at v-i?s option) v-infinity products not meeting v-i?s published specifications. nothing will be covered outside of standard product warranty. input parameter conditions/description min nom max units input voltage range 9 24 36 v dc 18 48 75 v dc under voltage lockout 24 vin power up 8.8 v dc 24 vin power down 8 v dc 48 vin power up 17 v dc 48 vin power down 16 v dc remote on/off control 4 section 15 in the application notes input filter pi type notes: 4. add suffix ?n? to the model number for negative logic on/off control
page date description: half-brick dc-dc converter 2 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W output parameter conditions/description min nom max units voltage accuracy 1.5 % transient response 25% step load change 500 sec external trim adj. range 10 % ripple & noise (20mhz bw) 3.3v, 5v 40 mv rms 100 mv pk-pk 12v& 15v 60 mv rms 150 mv pk-pk 24v 100 mv rms 240 mv pk-pk temperature coefficient 0.03 %/c short circuit protection continuous line regulation 5 0.2 % load regulation 6 1 % over voltage protection trip range, % vo nom. 115 140 % over current protection % nominal output current 110 140 % general specifications parameter conditions/description min nom max units switching frequency 250 khz operating ambient temp. 7 -40 100 c storage temperature -55 105 c thermal shutdown case temp. 90 c case material aluminum isolation specifications parameter conditions/description min nom max units isolation voltage input/output 1500 v dc input/case 1500 v dc output/case 1500 v dc isolation resistance 100 m notes: 5. measured from high line to low line at full load 6. measured from full load to zero load at nominal input 7. see output derating curve (page 4) *v-infinity reserves the right to make changes to its products or to discontinue any product or service without notice, and to advise customers to verify the most up-to- date product information before placing orders. v-infinity assumes no liability or responsibility for customer?s applications u sing v-infinity products other than repair or replacing (at v-i?s option) v-infinity products not meeting v-i?s published specifications. nothing will be covered outside of standard product warranty.
page date description: half-brick dc-dc converter 3 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W tolerances inches: x.xx= 0.02 , x.xxx= 0.010 millimeters: x.x= 0.5 , x.xx= 0 . 2 5 bottom view all dimensions in inches(mm) mounting inserts m3*0.5 through 4pl. 1 -sense -vout -vin case on/off +vout +sense trim 8 7 9 6 2 5 4 3 +vin function pin mechanical drawing
page date description: half-brick dc-dc converter 4 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W application notes 1. output de-rating the operating case temperature range for VHB150W is -40 ~ +100c. when operating the VHB150W series, proper derating or cooling is needed. the maximum case temperature under any operating condition should not exceed 100c. figure 1. output derating (forced convection with no heat sink) example: what is the minimum airflow necessary for a VHB150W-q48-s12 operating at nominal line, an output current of 12.5 a, and a maximum ambient temperature of 50c? solution: given: vin=48 v dc, vo=12 v dc, io=12.5 a determine power dissipation (pd): pd=pi-po=po(1- )/ pd=1212.5(1-0.9)/0.9=16.67 w determine airflow: given: pd=16.67 w and ta=50c check above power de-rating curve: minimum airflow= 500 ft./min. verifying: the maximum temp. rise t = pd rca=16.672.96=49.34c. the maximum case temperature tc=ta+ t=99.34c<100c where: the rca is thermal resistance from case to ambience.the ta is ambient temperature and the tc is case temperature. power dissipated vs ambient temperature and air flo w ambient temperature ,ta(deg. c) power disspated ,pd(watts) natural convection 20 ft./min. (0.1 m/s) 100 ft./min. (0.5 m/s) 200 ft./min. (1.0 m/s) 300 ft./min. (1.5 m/s) 400 ft./min. (2.0 m/s) 500 ft./min. (2.5 m/s) 600 ft./min. (3.0 m/s) 700 ft./min. (3.5 m/s) 800 ft./min. (4.0 m/s) chart of thermal resistance vs air flow air flow rate typical rca natural convection 20ft./min. (0.1m/s) 7.12 /w 100 ft./min. (0.5m/s) 6.21 /w 200 ft./min. (1.0m/s) 5.17 /w 300 ft./min. (1.5m/s) 4.29 /w 400 ft./min. (2.0m/s) 3.64 /w 500 ft./min. (2.5m/s) 2.96 /w 600 ft./min. (3.0m/s) 2.53 /w 700 ft./min. (3.5m/s) 2.37 /w 800 ft./min. (4.0m/s) 2.19 /w
page date description: half-brick dc-dc converter 5 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W 2. input voltage range it is important to ensure the input voltage measured at the converter input pins is within the range for that converter. make sure wire losses and voltage ripples are accounted for. one possible problem is driving the converter with a linear unregulated power su pply. for example, if the average voltage measured by a dmm is 9v, with a voltage ripple of 3vpp, the actual input can swing from 7.5 v to 10.5v. this will be outside the specified input range of 9-36v and the converter may not function properly. on the other end, make sure the actual input voltage does not exceed the highest voltage of 36v or75v. 3. lead wires make sure the input and output wires are of adequate awg size to minimize voltage drop, and ensure the voltage across the input terminals is above the converter's rated minimum voltage at all times. it is recommended to have the wire pairs twisted, respe ctively for the input pair and the output pair, so as to minimize noise pickup. 4. input current the input voltage source must be able to provide enough current to the converter, otherwise it may not start up or operate prop erly. a typical symptom is not starting or unusually low output voltage. in general, it is recommended to be able to provide at least: ipeak = 150%*pout/( *vmin) where pout is the maximum output power, vmin is the minimum input voltage and is the converter's efficiency. as an example, for VHB150W-q24-s5 to operate with 9~36 v input, 150 w output and an efficiency of 87%, the minimum source current is recommended to be: ipeak = 150% * 150 / (87% * 9) = 28.74 a . 5. input fuse to limit the input current and to facilitate input reversal protection and input ovp protection, a fast-acting input fuse is rec ommended for the input line. the fuse rating will depend on the input range and should allow for the maximum current at the lowest inpu t volt- age, as shown in this equation: ipeak = 150%*pout/( *vmin) . in the previous example of VHB150W-q24-s5, the peak input current at 9v was calculated to be 28.74 a. a 30 a fuse may be suitabl e for this application. make sure the fuse voltage rating is higher than the maximum input voltage. 6. remote sense the converter provides regulated outputs at the output terminals. when there is a large current and/or the output cable is of s ome length, the voltage at the end of the output cable may be noticeably lower than at the terminals. the converter can compensate up to 0.5v of voltage drop through remote sense terminals. to ensure accurate regulation, run two separate wires (twisted) from the desired regulation points to the remote sense terminals, as shown below. even if the load current is low, still connect +vo to +s and -vo to -s. +vo +s trim -s -vo (-) (+) load figure 2. remote sense
7. output trimming (optional) the output voltages are preset to nominal values as indicated by the models table at the factory. if desired, the output volta ge may optionally be trimmed to a different value (+/- 10%) with external resistors and/or potentiometer as shown below. to trim the output voltage with fixed resistors, the output voltage can be calculated as follows. trim-up trim-down figure 4: trim-up voltage setup figure 5: trim-down voltage setup the value of r trim-up is defined as: the value of r trim-down is defined as: where: r trim-up is the external resistor in k . vo,nom is where: r trim-down is the external resistor in k . vo,nom is the nominal output voltage. vo is the desired output voltage. the nominal output voltage. vo is the desired output voltage. r1 and r2 are internal to the unit and are defined in table 1. r1 and r2 are internal to the unit and are defined in table 2. for example, to trim-up the output voltage of 5.0v module for example, to trim-down the output voltage of 5.0v module (VHB150W-q48-s5) by 8% to 5.4v, r trim-up is calculated (VHB150W-q48-s5) by 8% to 4.6v, r trim-down is calculated as follows: as follows: page date description: half-brick dc-dc converter 6 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W r load 10k trimpot +vin -vin -vo -s trim +s +vo vo ?vo,nom ) ( vo ?vo,nom ) (k ? = 1 )) ( (r 2 r vo ? vo,nom ) ( vo ? vo,nom ) (k ? = 1 )) ( (r 2 r output voltage(v) r1 (kohm) r2 (kohm) 3.3v 3.168 7.2 5v 5.8 3.3 12v 18.945 4.636 15v 25.189 7.191 24v 41.442 6.977 table 1 r load r trim-up +vin -vin +vo +s trim -s -vo r load r trim-down +vin -vin +vo +s trim -s -vo 5 ? 5.4 ) ( 5 ? 5.4 9.18k ? = )) ( (5.8 3.3 vo ? vo,nom = 5.4 ? 5.0 = 0.4v = 5.8 k = 3.3 k 2 r 1 r = vo,nom ? vo = 5.0 ? 4.6 = 0.4v = 5.8 k = 5.32 k 2 r 1 r 4.6 ? 5 ) ( 4.6 ? 5 11.2k ? = = )) ( (5.8 5.32 figure 3. trimming with external potentiometer output voltage(v) r1 (kohm) r2 (kohm) 3.3v 6.18 15 5v 5.8 5.62 12v 86.45 60.1 15v 150 68 24v 430 120 table 2 vo ?vo,nom ) ( vo ?vo,nom ) (k ? = 1 )) ( (r 2 r vo ? vo,nom ) ( vo ? vo,nom ) (k ? = 1 )) ( (r 2 r
page date description: half-brick dc-dc converter 7 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W 10. output ocp and short-circuit protection output overload and short circuit conditional will cause the output voltage to decline or shutdown altogether. if the case te mperature is not over 100c, the output recovers automatically when the short or ocp conditions are removed. in the case of slight overlo ading, the output voltage may not shut down, but the converter may build up heat over time, causing over-temperature shutdown. 11. over-temperature protection when the case temperature reaches about 100c, the converter's built-in protection circuit will shut down the output. when the tem- perature is reduced enough to a safe operating level, the converter will recover to normal operations automatically. 12. output ovp in case the output voltage exceeds the ovp threshold, the converter shuts down. 13. output parallel connections the converter is not designed for load share on the output. one may be inclined to use this circuit to force current sharing b y trim- ming the output voltages for each converter. however, this circuit may not reliably or accurately divide the load current, as the device characteristics of the converters or the diodes may not be balanced over a range of operating conditions. we generally do not recom- mend this circuit to increase power output over a single converter. instead, we recommend this setup for redundancy only, havi ng one converter as a backup in case of a failure. make sure the or-ing diodes can handle the voltage and full load current. +vin -vin +vo -vo +vin -vin +vo -vo figure 6. output parallel connections
page date description: half-brick dc-dc converter 8 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W 14. output series connections two or more converters can be connected in series to obtain a higher output voltage. to prevent output reverse biasing each ot her in case of a short, add a schottky diode on each output in reverse polarity, as shown in the diagram. in the event of a short, th e con- verters will forward-bias the diodes and the output reversal will be limited to one diode drop (about 0.5v) only, so as not to damage the converters. the forward current will cause each converter to go into short-circuit protection. for proper diode selectio n, make sure that: 1) the diodes voltage rating is higher than each converter output; 2) the rated diode current can carry the short-ci rcuit cur- rent; 3) the diodes do not overheat before the short is removed. 15. remote output on/off control the converter output can be enabled or disabled through the on/off pin. the control logic is shown in this table. a common con trol circuit is shown below. the standard version defaults to positive logic. for negative logic, indicate the selection when orderi ng. 16. isolation the input and output of the converter are electrically isolated. if needed, an output terminal can be connected to an input te rminal, resulting in the converter non-isolated. logic table negative logic positive logic sw closed (v <0.8 v) output on output off sw open (v >2.4 v) output off output on rem rem sw high signal here disable output -vin (pin 4) rem (pin 2) rem -vin sw rem -vin -vo +vo figure 8. remote on/off control figure 9. remote on/off control with transistor switch +vin -vin +vo -vo +vin -vin +vo -vo figure 7. output series connections
page date description: half-brick dc-dc converter 9 of 9 08/2009 20050 sw 112 th ave. tualatin, oregon 97062 p h o n e phone 503.612.2300 f a x www.v-infinity.com fax 503.612.2383 part number: VHB150W 17. output filtering the converter has built-in capacitors at the output to control ripple and noise. if desired, additional output capacitance can be introduced at the input to the powered equipment. recommended starting point: one 10 f tantalum and one 1 f ceramic capacitor in parallel at the output. 18. output noise measurement schematic for proper output ripple and noise measurement, connect a 10 f tantalum and a 1 f ceramic capacitor across the output. set the scope bandwidth to 20mhz. probe directly off of one of the capacitors, using a small ground clip to minimize measurement error . resistor load to scope solid tantalum 10f ceramic 1.0f +vin -vin -vo -s trim +s + +vo figure 10. output noise measurement circuit
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