Document 621-1 Coupled Inductors–MSD7342 Series For SEPIC Applications The excellent coupling coefficient (k ≥ 0.94) makes the MSD7342 series of coupled inductors ideal for use in SEPIC applications. In SEPIC topologies, the required inductance for each winding in a coupled inductor is half the value needed for two separate inductors, allowing selection of a part with lower DCR and higher current handling. These inductors provide high inductance, high efficiency and excellent current handling in a rugged, low cost part. They can also be used as two single inductors connected in series or parallel, as a common mode choke or as a 1 : 1 transformer. D1 0.295 max 7,5 + Dot indicates pin 1 0.295 max 7,5 123 VIN 1 2 L1 L2 3 4 0.028 0,7 Recommended Land Pattern 0.110 2,8 0.091 2,3 0.083 2,1 3 4 2 1 2 1 3 4 0.130 3,3 0.043 1,10 0.063 1,6 Dimensions are in C1 L2 Q1 + Load – VOUT – Typical SEPIC schematic inches mm Core material Ferrite Terminations RoHS compliant matte tin over nickel over phos bronze. Other terminations available at additional cost. Weight 0.76 – 0.87g 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. Packaging: –40°C to +80°C Winding to winding isolation 200 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 250/7″ reel; 1000/13″ reel Plastic tape: 16 mm wide, 0.4 mm thick, 12 mm pocket spacing, 4.9 mm pocket depth PCB washing Only pure water or alcohol recommended Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2010 C2 Refer to Application Note, Document 639, “Selecting Coupled Inductors for SEPIC Applications” 0.181 max 4,6 0.150 3,8 + L1 Document 621-1 Revised 11/10/09 Document 621-2 Coupled Inductors for SEPIC Applications – MSD7342 Series Part number1 MSD7342-252ML_ MSD7342-332ML_ MSD7342-472ML_ MSD7342-562ML_ MSD7342-682ML_ MSD7342-822ML_ MSD7342-103ML_ MSD7342-123ML_ MSD7342-153ML_ MSD7342-183ML_ MSD7342-223ML_ MSD7342-273ML_ MSD7342-333ML_ MSD7342-393ML_ MSD7342-473ML_ MSD7342-563ML_ MSD7342-683ML_ MSD7342-823ML_ MSD7342-104ML_ MSD7342-124ML_ MSD7342-154ML_ MSD7342-184ML_ MSD7342-224ML_ MSD7342-274ML_ MSD7342-334ML_ MSD7342-394ML_ MSD7342-474ML_ MSD7342-564ML_ MSD7342-684ML_ MSD7342-824ML_ MSD7342-105ML_ Inductance2 ±20% (µH) DCR max3 (Ohms) SRF typ4 (MHz) 2.5 3.3 4.7 5.6 6.8 8.2 10 12 15 18 22 27 33 39 47 56 68 82 100 120 150 180 220 270 330 390 470 560 680 820 1000 0.033 0.037 0.051 0.063 0.070 0.075 0.100 0.120 0.130 0.170 0.220 0.250 0.270 0.380 0.420 0.460 0.600 0.680 0.770 1.03 1.35 1.52 1.72 2.41 2.70 3.05 4.00 4.43 5.00 6.80 7.80 55 43 35 32 30 27 22 20 18 15 13.5 12.0 11.0 10.0 9.5 8.7 7.3 6.2 5.5 4.5 4.0 3.8 3.5 3.3 3.0 2.8 2.6 2.5 2.3 2.2 2.0 Isat (A)5 10% drop 20% drop 30% drop 6.0 5.2 4.1 3.9 3.7 3.3 2.8 2.5 2.2 2.0 1.9 1.7 1.5 1.3 1.2 1.1 1.0 0.90 0.80 0.70 0.65 0.62 0.59 0.55 0.49 0.45 0.41 0.38 0.36 0.30 0.27 6.2 5.3 4.3 4.1 3.8 3.4 2.9 2.6 2.3 2.2 2.0 1.8 1.6 1.4 1.3 1.2 1.1 1.00 0.92 0.80 0.76 0.66 0.62 0.57 0.52 0.47 0.43 0.40 0.37 0.32 0.29 6.3 5.4 4.6 4.2 3.9 3.5 3.0 2.7 2.4 2.3 2.1 1.9 1.7 1.5 1.4 1.3 1.2 1.1 0.98 0.90 0.80 0.73 0.66 0.60 0.54 0.50 0.46 0.42 0.38 0.35 0.31 Irms (A) both one windings6 winding7 2.17 2.05 1.74 1.57 1.49 1.44 1.24 1.14 1.09 0.95 0.84 0.79 0.76 0.64 0.61 0.58 0.51 0.48 0.45 0.39 0.34 0.32 0.30 0.25 0.24 0.23 0.20 0.19 0.18 0.15 0.14 3.06 2.89 2.46 2.22 2.10 2.03 1.76 1.61 1.54 1.35 1.19 1.11 1.07 0.90 0.86 0.82 0.72 0.67 0.63 0.55 0.48 0.45 0.42 0.36 0.34 0.32 0.28 0.26 0.25 0.21 0.20 1. Please specify termination and packaging codes: Temperature rise calculation based on specified Irms MSD7342-105MLC 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: C = 7″ machine-ready reel. EIA-481 embossed plastic tape (250 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 C instead. D = 13″ machine-ready reel. EIA-481 embossed plastic tape. Factory order only, not stocked (1000 parts per full reel). 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. DC current, at which the inductance drops the specified amount from its value without current. It is the sum of the current flowing in both windings. 6. Equal current when applied to each winding simultaneously that causes a 40°C temperature rise from 25°C ambient. See temperature rise calculation. 7. Maximum current when applied to one winding that causes a 40°C temperature rise from 25°C ambient. See temperature rise calculation. 8. 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. Winding power loss = (IL12 + IL22 ) × DCR in Watts (W) 129°C Temperature rise (Δt) = Winding power loss × W 129°C Δt = (IL12 + IL22 ) × DCR × W Example 1. MSD7342-123ML (Equal current in each winding) Winding power loss = (1.14 2 + 1.14 2) × 0.120 = 0.312 W 129°C = 40°C Δt = 0.312 W × W Example 2. MSD7342-123ML (IL1 = 1.4 A, IL2 = 0.6 A) Winding power loss = (1.4 2 + 0.6 2) × 0.120 = 0.278 W Δt = 0.278 W × 129°C = 36°C W Coupled Inductor Core and Winding Loss Calculator 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. Visit www.coilcraft.com/coupledloss. Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2010 Document 621-2 Revised 11/10/09 Document 621-3 Coupled Inductors for SEPIC Applications – MSD7342 Series Typical L vs Current Typical L vs Frequency 10000 10000 1000 µH 100 µH 100 1000 µH 1000 470 µH Inductance (µH) Inductance (µH) 1000 47 µH 10 µH 10 470 µH 100 µH 100 47 µH 10 µH 10 4.7 µH 4.7 µH 1 1 0.01 1 0.1 10 0.1 Current (A) 1 10 100 Frequency (MHz) Irms Derating 120 110 90 80 70 60 50 40 25°C Percent of rated Irms 100 30 20 10 0 -40 -20 0 20 40 60 80 100 120 140 Ambient temperature (°C) Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2010 Document 621-3 Revised 11/10/09