View DI35_1232647.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Design Idea DI-35 (R) TOPSwitch-GX
16 W Audio Amplifier Power Supply
Application Audio Amplifier Device TOP245P Power Output 16 W (35 W Peak) Input Voltage 85-265 VAC Output Voltage 16 V Topology Flyback
Design Highlights
No heatsinks required! 77% efficiency (min), @ 85 VAC input/35 W output Low no-load input power: < 0.7 W @ 230 VAC input Low component count: 37, excluding I/O connectors Stable operation with or without 10,000 F output buffer capacitor * Robust transformer design enables 35 W peak power * Meets CISPR22B EMI with > 10 dB of margin * Ideal for both class AB and class D audio amplifiers * * * * *
The EMI filter has been significantly simplified to three components (L1, CX1 and CY1), thanks to the built-in frequency jitter function of the TOPSwitch-GX family. The RCD network of C4, R3, R4, and D5 limits (clamps) the peak voltage that the U1-DRAIN sees. A glass-passivated normal recovery diode (D5) recycles stored leakage energy, increasing overall efficiency. DRAIN ringing is dampened by R4 (which is necessary when a normal recovery diode is used). The bias winding provides operating power and feedback current to the CONTROL pin of U1. The U2-LED, R8 and VR1 comprise the feedback circuit that senses the output voltage. The current through the U2-LED regulates the output voltage, by modulating the feedback current that flows into the CONTROL pin of U1.
Operation
Many of the built-in TOPSwitch-GX features have been used to reduce the component count, transformer size, and overall cost of this universal input flyback power supply. Designed around a TOP245P (DIP-8 package), the device uses PCB copper for its heatsink, eliminating the costs of both a heatsink and the installation labor. Output diode D7 is also cooled the same way. Resistors R1 and R2 set the nominal Under-Voltage (UV) lockout and Overvoltage (OV) shutdown limits to 84 V and 378 V, respectively. UV lockout protects the supply from overheating at low line and eliminates power-up and powerdown glitches. OV shutdown protects the power supply from line surges.
Key Design Points
* Ensure that the control loop has enough phase margin at the extremes of the rated input voltage and output load, both with and without the output buffer capacitor. * A 5% VR1 should be acceptable for an audio amplifier. Greater accuracy will require a 2% VR1. * OV and UV thresholds are determined by: VOV = 225 A x (R1+R2) and VUV = 50 A x (R1+R2).
CY1 2.2 nF (Safety) 1 9, 10 D7 SB5100 R7 10 C7 C8 470 F 470 F 25 V 25 V R8 C5 150 1 F 50 V U2 PC817A U2 U2 R10 1k RTN R6 C6 33 470 pF 1/4 W 100 V L2 3.3 uH
R3 200 k 1/2 W D1 & D2 1N4007 C1 100 F 400 V D3 & D4 1N4007 L1 6.8 mH 0.8 A CX1 220 nF 250 VAC F1 3.15 A 250 V 85-265 VAC L N
S
C4 1 nF 1 KV
C9 100 F 25 V
16 V, 1 A / 2.2 A
R1 1M
3
6, 7 4
R2 1M
R4 33 1/4 W D5 IN4007G
M
5 T1 D6 BAV20
D
CONTROL
TOPSwitch-GX U1 TOP245P
C
C2 100 nF 50 V
R5 3.3 C3 100 F 16 V VR1 IN5244B 5% C10 47 F 25 V
Figure 1. Audio Amplifier Power Supply.
DI-35
PI-3731-012604
www.powerint.com
March 2004
DI-35
* Keep power loop layouts (primary and secondary) tight to minimize noise (EMI and output ripple) and power loss. * At least 10 cm2 of PCB copper area should be used for heatsinking.
16.1 16 15.9 15.8 15.7 15.6 15.5 15.4 15.3 15.2 15.1 15 0 0.5 1 1.5 2 2.5
TRANSFORMER PARAMETERS
Core Bobbin Nippon Ceramic EF-25-NC-2H ALG of 247 nH/T2 Miles-Platts FE0100 with TBS-601 terminals Primary: 65T, 2 layers, 28 AWG Secondary: 9T, 2 x 26 AWG, Triple Insulated Bias: 8T, 2 x 28 AWG
PI-3719-093003
Winding Details
VOUT (V)
Primary: 3-1, tape Winding Order (pin numbers) Secondary: 9,10-6,7, tape, Bias: 4-5, tape 3L Primary Inductance 1059 H 10%
Primary Resonant Frequency 0.75 MHz (Min) Leakage Inductance 28 H (Max)
Table 1. Transformer Construction Information.
IOUT (A)
THERMAL TEST RESULSTS
Thermal test load current is 1 A for 30 ms, 2.2 A for 10 ms T (C) @ T (C) @ Test Case 85 VAC 265 VAC T1 (Transformer) U1 (TOP245P D7 (Op Rectifier) 57 64 58 41 59 51 59 40
Figure 2. 115 VAC V-I Curve.
PI-3730-012604
7 6 5
Current (A)
4 3 2 1 0 -1 0 50 100 1A 2.2 A
C8 (Op Capacitor)
Table 2. Thermal Test with Pulsed Load of Figure 3. 25 C Ambiant, Open Frame, 85 VAC and 265 VAC input.
Time (ms) Figure 3. Load Current for Thermal Test. (10 ms/div)
For the latest updates, visit www.powerint.com Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your use of any information, device or circuit described herein nor does it convey any license under its patent rights or the rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES 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 (including circuits external to the products and transformer construction) 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. The PI logo, TOPSwitch, TinySwitch, LinkSwitch and EcoSmart are registered trademarks of Power Integrations. PI Expert and DPA-Switch are trademarks of Power Integrations. Copyright 2004, Power Integrations
Power Integrations
MAIN PHONE NUMBER +1 408-414-9200
A 3/04
5245 Hellyer Avenue
APPLICATIONS FAX +1 408-414-9760
San Jose, California 95138
For a complete listing of worldwide sales offices, please visit www.powerint.com
APPLICATIONS HOTLINE +1 408-414-9660
www.powerint.com

▲Up To Search▲

Price & Availability of DI35

	To Download DI35 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .