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Details, datasheet, quote on part number:DI-3
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| Part: | DI-3 |
| Category: | Power Management => Power Factor Controllers |
| Description: | Topswitch Burst Mode Flyback(r) |
| Company: | Power Integrations, Inc. |
| Datasheet: | Download DI-3 datasheet File size : 366 kB |
| Request For quote: | Find where to buy DI-3
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Datasheet text preview:
Design Idea DI-3 TOPSwitch ® Burst Mode Flyback
Application Industrial Bias Device TOP221P Power Output 100 mW Input Voltage 85 - 265 VAC
INTEGRATIONS, INC.
Output Voltage 5.1 V Topology
POWER
®
Burst Mode Flyback
Design Highlights
· Low cost isolated converter (competitive with capacitive dropper) · DC/DC or AC/DC markets · Wide range AC input applications · No inductive components required in EMI filter · Extremely low average EMI · Surge protection without MOV · Small physical size (1.2 in/30.5 mm × 2.2 in/55.8 mm)
bias supplies, utility meters, and other applications requiring extremely low system cost and low output power. The circuit is designed to replace conventional linear supplies and capacitor droppers, offering universal input range and higher output power than a conventional capacitor dropper supply. The example shown below delivers 5.1 V at 20 mA. Input voltage range is 85-265 VAC. Incoming AC is half-wave rectified and averaged by R1, R2, D1, D2, and C1, providing a DC voltage to one end of the primary winding of T1. The other end of the transformer primary is driven by the integrated high voltage MOSFET inside the TOP221. C2 is charged by the TOPSwitch internal current source to initiate operation and provide enough charge to sustain the TOPSwitch for 8-9 switching cycles per autorestart period. VR1 clamps the primary leakage spike at the TOPSwitch
Operation
The TOPSwitch burst mode flyback supply generates a single isolated output voltage from an AC or DC input. It is optimized for use with the TOP221 for outputs of 0-100 mW. The basic design can be scaled up to a maximum power of 200 mW with a different transformer design. Typical applications are industrial
D1 R1 750 1N4007
+
Flame proof
1 82T 36AWG 8
D4 1N4933 5T 30AWG C4 100 µF 35 V
R3 82 5.1 V VR2 1N4733 RTN
5 4 NC 10T 30AWG 3
2 AC INPUT C1 10 µF 400 V VR1 P4KE550
S TOP221P
T1 T1
D
TOPSwitch-II
CONTROL
C
D2 R2 750 1N4007
U1
C2 100 nF
C3 330 pF Y1
Flame proof
PI-2259-080398
Figure 1. TOPSwitch Burst Mode Flyback.
DI-3
www.powerint.com
June 1998
DI-3
DRAIN to a safe level. The power secondary winding of T1 is rectified and filtered by D4 and C4 to provide 7.5-8 V. R3 and VR2 step down this voltage to provide a regulated 5.1 V output. R3 is sized to provide 20 mA of output load current and 10 mA of bias current for Zener VR2 in order to maintain output regulation. A shunt regulator is used in this circuit to provide a constant load to the converter since the TOPSwitch runs open loop. R1, R2, C1 and C3 provide EMI filtering for the power supply. R1, R2 and C1 also protect the rest of the circuit against input line transients. The T1 bias winding (Pins 3 and 4) does not provide power for TOPSwitch, but acts as a shield to reduce EMI. In this circuit, the TOP221 runs repetitively in autorestart. The amount of power delivered in this mode is determined by the TOPSwitch auto restart duty cycle, which sets the ratio of switching time to idle time during autorestart, as well as the transformer primary inductance and the TOPSwitch current limit. With a 0.1 µF CONTROL pin capacitor, the TOP221 delivers a single burst of 8-9 pulses at 100 kHz, during each autorestart period, with approximately 1.2 ms between bursts. To stabilize output power over extremes of line voltage, T1 is designed for discontinuous mode, with each switching pulse terminated by the TOPSwitch current limit. Transformer parameters are shown in following table.
Transformer Parameters
Core Material TDK PC40EI12.5-Z or equiv. Gap for AL of 208 nH/T2 TDK BE-12.5-1110CP or equiv. Primary (2-1), Tape, Bias (34), Tape, Secondary (8-5) 1.4 mH ± 10% @ 100 kHz
Bobbin Winding Order Primary Inductance (Pins 1-2, all others open) Primary Resonant Frequency (Pins 1-2, all others open) Leakage Inductance (Pins 1-2, with Pins 5-8 shorted)
700 kHz minimum
70 µH maximum
Key Design Points
· Design transformer for discontinuous mode operation, with TOPSwitch reaching current limit each cycle. · Size R1, R2, and C1 to provide at least 70 VDC bus voltage at minimum AC line voltage and maximum load. · VR1 can be sourced by General Semiconductor (P4KE550). It can be replaced by a fast recovery diode (600V PIV) and series Zener clamp (BZY97-C200 or P6KE200) from DRAIN to Pin 1 of the transformer, as in conventional TOPSwitch designs.
For the latest updates, visit our Web site: www.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, nor does it convey any license under its patent rights or the rights of others. The PI Logo, TOPSwitch, TinySwitch and EcoSmart are registered trademarks of Power Integrations, Inc. ©Copyright 2001, Power Integrations, Inc.
WORLD HEADQUARTERS AMERICAS Power Integrations, Inc. San Jose, CA 95138 USA Customer Service: Phone: +1 408-414-9665 Fax: +1 408-414-9765 e-mail: usasales@powerint.com KOREA Power Integrations International Holdings, Inc. Seoul, Korea Phone: +82-2-568-7520 Fax: +82-2-568-7474 e-mail: koreasales@powerint.com
A 6/98
EUROPE & AFRICA Power Integrations (Europe) Ltd. United Kingdom Phone: +44-1344-462-300 Fax: +44-1344-311-732 e-mail: eurosales@powerint.com
TAIWAN Power Integrations International Holdings, Inc. Taipei, Taiwan Phone: +886-2-2727-1221 Fax: +886-2-2727-1223 e-mail: taiwansales@powerint.com INDIA (Technical Support) Innovatech Bangalore, India Phone: +91-80-226-6023 Fax: +91-80-228-9727 e-mail: indiasales@powerint.com
CHINA Power Integrations International Holdings, Inc. China Phone: +86-755-367-5143 Fax: +86-755-377-9610 e-mail: chinasales@powerint.com APPLICATIONS HOTLINE World Wide +1-408-414-9660 APPLICATIONS FAX World Wide +1-408-414-9760
JAPAN Power Integrations, K.K. Keihin-Tatemono 1st Bldg. Japan Phone: +81-45-471-1021 Fax: +81-45-471-3717 e-mail: japansales@powerint.com
www.powerint.com
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