DI-147 PKS607YN CISPR-22/EN55022B P6KE200A 1N4007 UF4005 1N4148 EER28 1N5254B

PeakSwitch ® Multiple Output Power Supply for Audio Amplifiers Application Device Power Output Input Voltage Output Voltage

DI-147 DI-147 Design Idea PeakSwitch ® Multiple Output Power Supply for Audio Amplifiers Application Device Power Output Input Voltage Output Voltage Topology Audio PKS607YN PKS607YN 60 W, 200 W pk 195 265 VAC ±26 V, -15 V, 10 V, 5 V Flyback Design Highlights · Effectively replaces linear transformer-based power supplies in home audio applications · Low component count, compact and lightweight · Energy efficiency · >75% efficiency at full load (60 W) · 25 A flows into the EN/UV pin. Two independent feedback loops are used to control the voltages on the ±26 V outputs. This ensures that both outputs are tightly regulated and also ensures better cross-regulation between all outputs over line and load. Key Design Points · The high crest factor of the music source allows for smaller heatsinks. · The auxiliary -15 V, 5 V and 10 V outputs are obtained from a linear regulator. To limit the power dissipation in the (5 V and 10 V) linear regulators, a second 17 V output was added to T1. · As the value of X capacitor C1 is above 0.1 F, safety agency requirements specify that R1 and R2 should be used to discharge C1 such that C1 × (R1 + R2) 1S. · To reduce group pulsing of switching cycles, a high gain optocoupler U2 (U3) was used. Capacitor C34 (C35) adds high frequency gain to the feedback signal. · In a three wire system, placing Y capacitors (C17, C18) between line/neutral and earth helps reduce common mode EMI. · The core size and the winding wire diameter sizes (see Table 1) were chosen based on the average of the peak and the continuous output power. · A drain to source snubber (R25, C40 and R26, C41) was added to reduce radiated EMI. PI-4889-111207 PI-4889-111207 Common mode choke, L1, and the four Y-capacitors, C9, C17, C18 and C25, form the common mode EMI filter. Common mode choke L1 also works in conjunction with X-capacitor C1 to provide differential mode EMI filtering. 70 QP 60 AV dB V 40 30 20 10 0 -10 -20 0.15 1.0 10.0 100.0 MHz Figure 2. Conducted EMI at 230 VAC With Output Grounded (CISPR-22 CISPR-22 Limit Lines Shown). Transformer Parameters Core Material EER28 EER28 NC-2H or equivalent, gapped for ALG of 100 nH/t² Bobbin EER28 EER28, 12 pin, Vertical Winding Details Add 3 mm margins on both sides of bobbin Primary: 18T × 2, AWG31 AWG31, tape Shield: 1T × 1, Foil 2 mils thickness, 3 layers tape 17 V: 6T × 2, AWG26 AWG26, tape 26 V: 8T × 4, AWG23 AWG23, 3 layers tape Bias: 5T × 2, AWG28 AWG28, tape Primary: 18T x 2, AWG31 AWG31, 2 layers tape Winding Order Primary (3-2), Shield (NC-1),17 V (12-11), 26 V (9,10-7,8), Bias(4-5), Primary (2-1) Primary Inductance 129 H, ±12% Primary Resonant Frequency 2 MHz (minimum) Leakage Inductance 5 H (maximum) Table 1. Transformer Parameters. (NC = No Connection) Power Integrations 5245 Hellyer Avenue San Jose, CA 95138, USA. Main: +1 408-414-9200 Customer Service Phone: +1-408-414-9665 Fax: +1-408-414-9765 Email: usasales@powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES NO WARRANTY HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS. The products and applications illustrated herein (transformer construction and circuits external to the products) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations' patents may be found at www.powerint.com. Power Integrations grants its customers a license under certain patent rights as set forth at http://www.powerint.com/ip.htm. On the Web www.powerint.com The PI logo, TOPSwitch, TinySwitch, LinkSwitch, DPA-Switch, PeakSwitch, EcoSmart, Clampless, E-Shield, Filterfuse, StackFET, PI Expert and PI FACTS are trademarks of Power Integrations, Inc. Other trademarks are property of their respective companies. ©2007, Power Integrations, Inc. A 11/07 DI-147 DI-147