2 Noise Suppression Devices AMOBEADS An amorphous noise suppression device is unique and completely different from conventional noise filters. Conventional noise prevention products focus on somehow minimizing the noise after it's been created, by typically trying to absorb the noise, and so their effectiveness in noise reduction is directly influenced by frequency of the circuit. Amorphous noise suppressing devices, on the other hand, focus on the source of the noise and work to prevent or minimize the noise before it has a chance to develop. The source of the electronic circuit noise is the rapid change of current or voltage, and the effectiveness of the amorphous cores in eliminating this noise is independent of frequency. An amorphous noise suppression device is a product that takes full advantage of the unique magnetic characteristics of the cobalt based amorphous alloy. Toshiba Materials offers two noise suppression devices, "AMOBEADS " and "SPIKE KILLERS ". AMOBEADS " deliver excellent noise suppression results and are convenient to use by simply being slipped over the leads of the semiconductor device. "AMOBEADS " are also available with a lead thru and in a surface mount configuration. "SPIKE KILLERS ", which are larger in size than "AMOBEADS ", most often are wire wound and are effective in eliminating or minimizing higher noise levels. C Noise Suppression Device R AB RC Snubber Magnetic Snubber Basic Snubber Circuit Diagram B[T] 0.6 Amorphous 0.4 Ferrite 0.2 -80 -40 0 -0.2 40 80 H [A/m] -0.4 -0.6 100 kHz, RT B-H Curvetypical Example for Noise Suppressing Effect (Chopper Converter) With an excellent saturable characteristic, "AMOBEADS " suppress the reverse recovery current of the diode and decrease the noise that is occurring. When the current for diode reverses and tries to go into the recovery condition, the "AMOBEADS " displays a large inductance and oppose the generation of the recovery current. In this instance, a soft recovery is possible for core material with a smaller coercive force. Output Noise Diode Current A/div Without Countermeasure With AMOBEADS (AB4x2x8W) - 8 - ABLB Series RoHS compliant products Standard Specifications AMOBEADS W series Type No. AB3X2X3W Finished Dimensions [mm] O.D. max I. D. min H.T. max 4.0 1.5 4.5 Core Size [mm]1 O.D. I. D. H.T. 3.0 2.0 3.0 Total Flux2 c[Wb] min 0.9 AL value3 L[H] min 3.0 AB3X2X4.5W 4.0 1.5 6.0 3.0 2.0 4.5 1.3 5.0 AB3X2X6W 4.0 1.5 7.5 3.0 2.0 6.0 1.8 7.0 AB4X2X4.5W 5.0 1.5 6.0 4.0 2.0 4.5 2.7 9.0 AB4X2X6W 5.0 1.5 7.5 4.0 2.0 6.0 3.6 12.0 AB4X2X8W 5.0 1.5 9.5 4.0 2.0 8.0 4.8 16.0 DY series (low price) Type No. Finished Dimensions [mm] Total Flux*7 c[Wb] Insulating Cover 4.00.2 4.00.2 4.00.2 5.00.2 5.00.2 0.9min 0.9min 1.3min 2.7min 3.6min PBT PBT PBT PBT PBT H.T. PBT case Blue 2,000 [pcs/box] 5.70.3 4.20.3 5.70.3 5.70.3 7.20.3 Packing Unit [pcs/bag Black Black Gray Black Black 10,000 10,000 10,000 5,000 5,000 Inner diameter can pass through a 1.20.7mm lead. AMOBEADS Packing Unit Recommend for big demand, 10,000pcs/lot ) O.D. AB2.8X4.5DY AB3X2X3DY AB3X2X4.5DY AB4X2X4.5DY AB4X2X6DY Insulating Cover W series DY sereis with lead Bulk type Finished Dimensions [mm] Type No. *4 *2 B *3 Current Total flux AL Value Insulating Packing Unit Cover [A] c[Wb] L[H] B D E F LB4X2X8F 16.0max 4.20.5 14.01.0 1.250.1 8.0 LB4X2X8U 20.0max 4.00.5 5.01.0 1.250.1 4.8 min 16.0 min B F PBT case 1,000 Black [pcs/box] D E LB4X2X8F Radial taping Type No. P [mm] Po [mm] LB2.8X4.5U 12.7 Do [mm] a [mm] 12.7 4.0 9.0max Current4 d [mm] I [A] 0.8 Flux7 Total c[Wb] (5) 0.9min Packing Unit D0 P0 Finished Dimensions [mm] Lead width length height width x thickness 4 2 Io [A] Total Flux c[Wb] 3 AL value Insulating Cover L[H] AB3X2X3SM 5.00.3 5.00.3 4.00.3 (1.8x0.35) 6.0 0.9 min 3.0 AB4X2X6SM 6.00.3 8.00.3 5.00.3 (1.8x0.52) 9.0 3.6 min 12.0 Packing Unit [pcs/reel] 2,000 LCP case Black 1,000 Recommended Land Pattern (mm) 2.4 H L W 2.0 9.4 2.4 3.3 AB3X2X3SM 1 Reference Value 2 Minimum Guarantee on Measuring Condition : 50kHz80A/m(sine wave), R.T. 3 Measuring Condition50kHz, 1V, 1turn, R.T. 4 Typical Value, using a cross section of lead 5 Measuring Condition100kHz, 80A/m sine wave), R.T. 6 Tolerance 0.2mm 7 Converted from Inductance Value L1 at 1kHz 100mA(sine wave)R.T. (Wb)0.282 x L1() "AMOBEADS "AMOBEADS "AMOBEADS " sample kits are available. Please ask sales department. " and "SPIKE KILLER " : Registered trademarks of TOSHIBA MATERIALS Co., Ltd. " and "SPIKE KILLER " : Resistered in U.S.A., France, Germany, U.K., Japan. - 9 - 14.7 AB4X2X6SM F LB4X2X8U P 3,000 [pcs/box] SMD Type AMOBEADS Type No. D E Examples of Applied Circuits and their Characteristics Application of Amorphous Noise Suppression Devices AB M AB AB Chopper Converter Control Circuit for Motor AB AB AB M AB Flyback Converter AB AB Motor Driving Circuit AB 100 Forward Converter AB4x2x8W AB4x2x6W AB4x2x4.5W AB AL value] 10 AB AB3x2x6W AB3x2x4.5W 1 AB2.8x4.5DY AB3x2x3W Push-pull Converter Characteristics (Typical value) 1k 100k Frequency f [Hz] 1M 100 (t)/(25) Pfe [kW/m3 1000 100 500kH z 300kH z 50 200kH z 100kH z Typical value R.T. Sine Wave 50kH z 1 0.01 10k Frequency Characteristics of Inductance 10000 10 Typical Value R.T. 0.1 0.1 0. 1 0 B | [T] 20 40 60 80 100 120 Temperature [] Flux() Decline Ratio vs. Temperature Coreloss Characteristic [AMOBEADS ] - 10 - Effects of Noise Suppression by AMOBEADS Spike Voltage Suppression Without Countermeasure Spike voltage can be reduced and ringing phenomena can also be prevented by AMOBEADS. Also Schottky barrier diode (SBD) can be protected from over voltage. Diode Voltage VD 10V/div Frequency500kHz Output Voltage - Current 5-20 Output Noise Reduction AMOBEADS "AB4x2x4.5" Diode Current ID 5A/div AMOBEADS "AB4x2x4.5" RC Snubber +Ferrite Beads When the ferrite is replaced by AMOBEADS at the secondary output diode (FRD) of the forward converter circuit, the output noise can be tremendously reduced, not only the noise peak level but also the amplitude range. Output Noise VN 20mv/div Frequency150kHz Output Voltage - Current 15-10 Ferrite Beads 4x2x4 AMOBEADS "AB4x2x4.5" Primary Surge Voltage MOS-FET Drain-Source Voltage VDS 200V/div When the ferrite is replaced by AMOBEADS at the secondary output diode (SBD) of the forward converter circuit, the output noise and harmful influence to the primary stage can be reduced. These effects are based on the inclination of the actual BH curves between amorphous and ferrite materials. Frequency250kHz Output Voltage - Current 5-15 Output Noise VN 50mv/div Output Noise B H Actual BH Curve BH characteristics of Ferrite - 11 - BH characteristics of Amobeads