Document 499-1 Coupled Inductors MSD1278 For Flyback, SEPIC, Zeta and other Applications • Tight coupling (k ≥ 0.98) and 500 V isolation • High inductance and high efficiency • Excellent current handling • Ideal for use in a variety of circuits including flyback, multi-output buck, SEPIC and Zeta. • Can also be used as two single inductors connected in series or parallel or as a common mode choke. + + D L1 C L2 VOUT C VIN – SW – Typical Flyback Converter D L2 + VOUT C AUX – + 0.484 max 12,3 0.484 max 12,3 123 X + VIN Dot indicates pin1 L1 D SW – – Typical Buck Converter with auxiliary output Dash number Internal code D + L1 VIN 0.317 max* 8,05 Recommended Land Pattern 0.197 5,0 3 2 3 0.059 1,5 * For optional tin-lead and tin-silver-copper terminations, dimensions are for the mounted part. Dimensions before mounting can be an additional 0.012 inch (0,3 mm). L2 C + 1 Q 0.177 4,5 4 VIN – 0.079 2,0 1 VOUT – Typical SEPIC schematic + 2 1 + C1 Q – 0.157 4,0 4 inches Dimensions are in mm C 0.217 5,5 0.197 5,0 0.138 3,5 VOUT C C L2 C1 L1 D Typical Zeta schematic C VOUT – 2 L1 L2 4 3 1:1 Document 499-1 Revised 04/05/13 Document 499-2 Coupled Inductors – MSD1278 Series Inductance2 DCR max3 SRF typ4 Part number1 (µH) (Ohms) (MHz) Irms (A) CouplingLeakage one windings7 winding8 typ typ (µH) (A) coefficient inductance5 Isat6both MSD1278-472ML_ 4.7 ±20% MSD1278-562ML_ 5.6 ±20% MSD1278-682ML_ 6.8 ±20% MSD1278-822ML_ 8.2 ±20% MSD1278-103ML_ 10 ±20% 0.038 0.046 0.048 0.050 0.058 32.0 25.0 24.0 18.0 16.5 0.98 0.98 0.98 0.98 0.98 0.22 0.23 0.22 0.34 0.34 14.9 13.4 13.1 10.8 10.5 3.16 2.87 2.81 2.76 2.56 4.47 4.06 3.98 3.90 3.62 MSD1278-123ML_ 12 ±20% MSD1278-153ML_ 15 ±20% MSD1278-183ML_ 18 ±20% MSD1278-223ML_ 22 ±20% MSD1278-273ML_ 27 ±20% 0.062 0.072 0.080 0.096 0.120 14.5 11.8 10.5 9.0 8.4 0.98 0.99 0.99 0.99 0.99 0.36 0.41 0.37 0.41 0.43 9.6 9.1 8.0 6.8 6.5 2.48 2.30 2.18 1.99 1.78 3.50 3.25 3.08 2.81 2.52 MSD1278-333ML_ 33 ±20% MSD1278-393ML_ 39 ±20% MSD1278-473ML_ 47 ±20% MSD1278-563ML_ 56 ±20% MSD1278-683ML_ 68 ±20% 0.150 0.160 0.180 0.190 0.210 7.6 6.5 6.0 5.6 5.0 0.99 0.99 0.99 0.99 0.99 0.56 0.64 0.70 0.76 0.88 5.6 5.5 5.2 4.5 4.1 1.59 1.54 1.45 1.41 1.35 2.25 2.18 2.05 2.00 1.90 MSD1278-823ML_ 82 ±20% MSD1278-104ML_ 100 ±20% MSD1278-124KL_ 120 ±10% MSD1278-154KL_ 150 ±10% MSD1278-184KL_ 180 ±10% 0.280 0.300 0.410 0.460 0.510 4.1 3.6 3.2 3.0 2.7 0.99 >0.99 0.99 >0.99 >0.99 0.85 0.90 1.31 1.46 0.93 3.8 3.4 3.2 2.8 2.5 1.16 1.13 0.96 0.91 0.86 1.65 1.59 1.36 1.29 1.22 MSD1278-224KL_ MSD1278-274KL_ MSD1278-334KL_ MSD1278-394KL_ MSD1278-474KL_ 0.690 0.900 1.02 1.12 1.43 2.5 2.1 2.0 1.8 1.6 >0.99 >0.99 0.99 >0.99 >0.99 1.54 1.17 4.14 1.64 0.25 2.3 2.1 1.9 1.7 1.6 0.74 0.65 0.61 0.58 0.50 1.05 0.92 0.86 0.82 0.70 1.69 2.29 2.55 2.83 1.5 1.4 1.3 1.1 >0.99 >0.99 >0.99 >0.99 2.68 2.11 2.39 4.28 1.5 1.3 1.2 1.1 0.47 0.41 0.39 0.37 0.67 0.58 0.55 0.52 220 ±10% 270 ±10% 330 ±10% 390 ±10% 470 ±10% MSD1278-564KL_ 560 ±10% MSD1278-684KL_ 680 ±10% MSD1278-824KL_ 820 ±10% MSD1278-105KL_ 1000 ±10% 1. When ordering, please specify termination and packaging code: Coupled Inductor Core and Winding Loss Calculator MSD1278-105KLD Termination:L= RoHS compliant matte tin over nickel over phos bronze Special order: T = RoHS tin-silver-copper (95.5/4/0.5) or S = non-RoHS tin-lead (63/37). Packaging: D= 13″ machine-ready reel. EIA-481 embossed plastic tape (500 parts per full reel). B=Less than full reel. In tape, but not machine ready. To have a leader and trailer added ($25 charge), use code letter D instead. 2. Inductance shown for each winding, measured at 100 kHz, 0.1 Vrms, 0 Adc on an Agilent/HP 4284A LCR meter or equivalent. When leads are connected in parallel, inductance is the same value. When leads are connected in series, inductance is four times the value. 3. DCR is for each winding. When leads are connected in parallel, DCR is half the value. When leads are connected in series, DCR is twice the value. 4. SRF measured using an Agilent/HP 4191A or equivalent. When leads are connected in parallel, SRF is the same value. 5. Leakage inductance is for L1 and is measured with L2 shorted. 6. DC current, at which the inductance drops 30% (typ) from its value without current. It is the sum of the current flowing in both windings. 7. Equal current when applied to each winding simultaneously that causes a 40°C temperature rise from 25°C ambient. See temperature rise calculation. 8. Maximum current when applied to one winding that causes a 40°C temperature rise from 25°C ambient. See temperature rise calculation. 9. Electrical specifications at 25°C. Refer to Doc 639 “Selecting Coupled Inductors for SEPIC Applications.” Refer to Doc 362 “Soldering Surface Mount Components” before soldering. This web-based utility allows you to enter frequency, peak-to-peak (ripple) current, and Irms current to predict temperature rise and overall losses, including core loss. Go to online calculator. Designer’s Kit C400 contains 3 each of all values. Core material Ferrite Core and winding loss Go to online calculator Terminations RoHS compliant matte tin over nickel over phos bronze. Other terminations available at additional cost. Weight: 3.7 – 4.4 g Ambient temperature –40°C to +85°C with Irms current, +85°C to +125°C with derated current Storage temperature Component: –40°C to +125°C. Tape and reel packaging: –40°C to +80°C Winding-to-winding and winding-to-core isolation 500 Vrms Resistance to soldering heat Max three 40 second reflows at +260°C, parts cooled to room temperature between cycles Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C / 85% relative humidity) Failures in Time (FIT) / Mean Time Between Failures (MTBF) 38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332 Packaging 500/13″ reel; Plastic tape: 24 mm wide, 0.5 mm thick, 16 mm pocket spacing, 8.7 mm pocket depth PCB washing Tested to MIL-STD-202 Method 215 plus an additional aqueous wash. See Doc787_PCB_Washing.pdf. Document 499-2 Revised 04/05/13 Document 499-3 Coupled Inductors – MSD1278 Series Typical L vs Current Typical L vs Frequency 10000 10000 -105 -474 -104 100 -473 -103 10 -105 1000 Inductance (µH) Inductance (µH) 1000 -474 -104 100 -473 -103 10 -472 1 0.1 1 -472 10 100 Current (A) 1 0.01 0.1 1 10 Frequency (MHz) Current Derating 100 90 80 70 60 50 40 30 20 10 0 25°C Percent of rated current 120 110 Isat Irms -40 -20 0 20 40 60 80 100 120 140 Ambient temperature (°C) Document 499-3 Revised 04/05/13