international rectifier irdc2086s- df d emo b oard e valuation p rocedure international rectifier ? 233 kansas street, el segundo, ca 90245 usa overview this docu m ent describes how to conne c t and evaluate the supplied irdc2086s- df de m o board. the de m o board incorporates a new dc bus converter chipset in a fi xed-frequency, open-loop isolated full-bridge dc-dc converter with 4:1 input to output volta ge conversion ratio. the chipset consis ts of a primary side ic (ir2086s), two 80v primary side fets (irf7493), two 30v secondary side fets (irf 6603), a primary side biasing fet (irf7380) and a secondary side gate clamp fet (irf9956). the front side and back side of the demo board are shown in fig. 1. fig. 1 front side and back side of the dc bus converter demo board with ir2086s chipset with marked input and output pins. +vout -vout -vin +vin downloaded from: http:///
international rectifier irdc2086s-s quick evaluation procedure to evaluate the operation and perfor m ance of the irdc2086 s - df de m o board, connect a p o wer supply to its input terminals, and a power load to its output terminals. input and output terminals are marked in fig. 1. to duplicate the performance data reported on page two, approximately 400 lfm of airflow is needed across the module. irdc2086s-s demo board description and circuit capability the circuit is designed to d e liver contin u ous 20a o u t p ut current in 36v C 5 4 v i n put v o ltage range, with 4 0 0 lfm of airflow. output voltage for this input voltage range will vary from 9v to 13.5v, and the total available output power from the module will range from around 180w at 36v to up to 270w at 54v input. the circuit will start to operate as soon as the primary v cc reaches about 9v C typically at 12vin. at this low input voltage, the output voltage will be only about 3v, and the secondary vcc will be insufficient to turn on channels of the secondary side synchronous rec tifier mosfets. to avoid ex cessive body diode conduction losses, output current during slow input voltage ramp-up should be set at less than 2a. full output current can be applied in the above specified input voltage range. a complete schematic of the demo board is shown in fig. 2. the circuit design is optimized in order to demonstrate true performance of the ir2086s control ic, irf7493 prim ary fets and irf6603 secondary fets. therefore, no test pins are available on the board. to pr obe the circuit waveforms use an oscilloscope probe with minimal length for the ground pin and connect dir ectly to the pins of the ic / mosfet device. fig. 2 compl e te sch e matic of i r dc2086s- df de m o b o a r d +48v rb3 vcc c8 db3 nm6 nm7 nm1 nm2 c9 rb2 nm5 t c1 vcc r1 d2 l cb2 db6 c4 c2 c6 rg1 rg2 vcc +48v rb4 rb1 nm5 db1 db2 nm3 nm4 c3 d1 g 5 vs1 14 vs2 11 g 13 vb2 9 ho2 10 cs 2 ct 4 d 3 lo1 6 vcc 7 lo2 12 ho1 15 vb1 16 ic1 vcc c5 cs c10 t2a cs r3 r2 c7 r4 rm t2b db4 db5 r5 c11 downloaded from: http:///
international rectifier fig. 3 efficiency at 48vin, 240w out max, 12vout, 200khz, and 400lfm air flow fig. 4 thermal image of ir2086s demo board at 48vin, 20aout, and 400lfm air flow to measure circuit efficiency, voltage and current at the i nput and output of the demo board need to be accurately measured. use of calibrated shunts for input and output current measurements is strongly recommended, as is use of a thermal camera for thermal performance evaluation. typical efficiency and a thermal image for 240w output power at 48vin are shown in fig. 3 and 4. inputs and out puts of two or more modules can be connected in parallel to provide required higher output power. due to natural output voltage droop associated with open-loop operation, no additional circuitry is required for relatively accurate current sharing (in the range of +/-10%). efficiency for 48v full-bridge dc bus converter using ir2086s irf7493 x 4 primary, irf6603 x 2 secondary 86 87 88 89 90 91 92 93 94 95 96 97 2.5 5 7.5 10 12.5 15 17.5 20 io [a] efficiency [%] 80v primary fet irf7493 : 79c 30vn secondary fets irf6603 : 71c front side back side downloaded from: http:///
international rectifier as shown in fig. 2, the primary side current is sensed with a current transformer. the current transformer turns ratio is 150 to 1. the sensed ac current information is rectified and then provided as an input into the current sense pin of the ir2086s after some rc filtering. fig. 5 shows the output voltage during current hiccup mode. the current limit was set approximately at 22a and the load was increased over the current trip point. it can be seen that the controller ir2086s attempts to turn on the converter once in a period of 500ms. the 500ms period is determined by the external capacitance of c5 (100nf). fig. 6 shows all the pcb layers. the gerber files are availabl e upon request. table 1 lists all the components for the demo board. fig. 5: output voltage waveform during hiccup mode at current limit setting of 22a downloaded from: http:///
international rectifier top layer bottom layer layer #1 layer #2 layer #3 layer #4 layer #5 layer #6 f i g. 6 i r d c 2 0 8 6 s - df de m o b oa r d p cb l a y o u t ( t o tal o f 8 l a yer s ) downloaded from: http:///
international rectifier table1. irdc2086s- df dc bus con v erter demo board bom used designator footprint description part value tolerance disti part # mfg 2 c5, cb2 603 ceramic capacitor 0.1ufd 16v grm188r71c104ka01d murata 1 r2 603 thick film 1.8k 5% 311-1.80khtr-nd digi-key 1 c10 1210 ceramic capacitor 10ufd 16v grm32nf51c106za01l murata 4 c2, c3, c4 603 ceramic capacitor 1.0ufd 16v grm188r61c105ka93d murata 2 c1, c11 1812 ceramic capacitor 1.0ufd 100v ecj5yb2a105m panasonic 1 db2 sod323f zener bzt52c3v0sdict -nd 3v bzt52c3v0sdict-nd digi-key 1 r3 603 thick film 7.5 1% 311-7.50htr-nd digi-key 1 db6 sod323 zener bzt52c9v1sdict-n d 9v bzt52c9v1sdict-nd digi-key 4 r4, r5 rg1, rg2 603 thick film 10k 5% 311-10.0khtr-nd digi-key 1 c7 603 ceramic capacitor 10nfd 16v lll185r71e103ma01l murata 2 c8, c9 1812 ceramic capacitor 22ufd 16v ecj5yb1c226m panasonic 1 db1 sod323f zener bzt52c12dict-nd 12v bzt52c12dict-nd digi-key 2 rb3, rb4 805 thick film 39k 5% 311-39.0khtr-nd digi-key 1 c6 603 ceramic capacitor 47pfd 50v grm1885c1h470ja01d murata 1 r1 603 thick film 60.4k 1% 311-60.4khtr-nd digi-key 3 d1, d2, db3 sod123 rectifier bav16wdict 75v bav16wdict-nd digi-key 2 rb1, rb2 1206 thick film 200 5% 311-200ftr-nd digi-key 2 db4, db5 sot23 rectifier bat54s 30v bat54s internationsl 1 l loutd inductor core planer inductor * e14/3.5/5-3f3 e14/3.5/5-3f3-a160 ferrox cube 1 ic1 so-16 integrated circuit ir2086s 9.5-16.0v ir2086s international rectifier 1 t pri_td inductor core planer transformer gap = 5 mil pq20/16-3f3 (8.4mm) 250fn029 (2.5mils kapton) 113-576 (kapton tape) ferrox cube dupont contact east 2 nm6, nm7 6603 transistor irf6603 30v irf6603 international rectifier 1 nm5 so-8 transistor irf7380 80v irf7380 international rectifier 4 nm1, nm2, nm3, nm4 mlp1 transistor irf7493 80v irf7493 international rectifier 1 nm8 so-8 transistor irf9956 80v irf9956tr international rectifier 1 t2 t2a ct-current transformer * pcd1548ct-nd digi-key downloaded from: http:///
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