View RD7_1300990.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

(R) TOPSwitch-II
RD7
(R)
PC Standby Reference Design Board
90 to 375 VDC Input, 3.5 W Output
Product Highlights
Low Cost Production Worthy Reference Design * Up to 3.5 W of output power * Meets Blue Angel requirements (5 W) * Single sided board * Low cost through-hole components * Fully assembled and tested * Easy to evaluate and modify * Extensive performance data * Light weight - no heat sink required for TOPSwitch-II * Non-isolated +12 V output option Fully Protected by TOPSwitch-II * Primary safety current limit * Output short circuit protection * Thermal shutdown protects entire supply Designed for World Wide Operation * Designed for IEC/UL safety requirements * Designed for wide range of input voltage Typical Applications * Desktop PC stand-by power supply (PS98, ATX, NLX, SFX, Micro ATX) * Consumer stand-by supply (e.g. TV, VCR, DVD)
Figure 1. RD7 Overall Physical Dimensions.
1.19 in. (29 mm)
2 in. (48 mm)
.75 in. (18 mm)
PI-2271-062998
PARAMETER Input Voltage Range Temperature Range Output Voltage (Io = 0.7 A) Output Power (continuous) Line Regulation (90-375VDC) Load Regulation (10%-100%) Efficiency (At full load) Output Ripple Voltage Safety
LIMITS 90 to 375 VDC 0 to 50 C 5 V 5% 3.5 W 1.0% 1.0% 72% 50 mV IEC950/UL1950
Description
The RD7 reference design board is an example of a very low cost production worthy DC input standby power supply design using the TOPSwitch-II family of Three-terminal Off-line PWM switchers. The reference design board is intended to help TOPSwitch-II users quickly develop their products. It provides a basic design that can be easily modified to fit a particular application. The RD7 operates from a rectified and filtered AC mains voltage and provides 3.5 W output at 5 V. Features such as a 12 V non-isolated output or tighter output voltage tolerance may be implemented by changing only a few components (See Figure 4).
Table 1. Table of Key Electrical Parameters.
April 1999
RD7
T1 C2 2.2 nF 1 KV D2 C3 1N5822 270 F 25 V L1 3.3 H
+
5 V - 5% 0.7 A
+
RF1 1
R1 47 k
* Css
VR1 IN5228C
C4 100 F 25 V
C1 10 nF 1 KV D1 UF4005 D3 1N4148 C6 0.1 F 50 V R3 100 U2 PC817A
Fusible 90-375 VDC Input
D
TOPSwitch-II
CONTROL
C
R2 10 CC* 0.1 F C5 47 F 10 V
S
TOP221P U1
* optional component, not populated
PI-2187-062998
Figure 2. Schematic diagram of the RD7.
S/N
RF1
D2
R1 J1 C1 C2 D1 JP1 U1 C5 C6 D3 U2 R3 R2
C3 L1 VR1 T1
C4 J2
COMPONENT SIDE SHOWN
PI-2269-070298
Figure 3. RD7 Pinout and Component Legend.
CAUTION
The RD7 is designed for DC input. Please observe the proper polarity when applying power to this board. Applying reverse polarity or AC power to the input terminals of the board can damage the TOPSwitch.
2
B 4/99
RD7 Component Listing
Reference C1 C2 C3 C4 C5 C6 Cc* Css* D1 D2 D3 L1 RF1 R1 R2 R3 T1** U1 U2 VR1 Value 10 nF, 1 KV, Disc 2.2 nF 1 KV, Disc 270 F 25 V 100 F 25 V 47 F, 10 V 0.1 F, 50 V 0.1 F, 50 V 600 V, 1A, UFR 40 V, 3 A, Schottky 75 V, Switching 3.3 H, 5 A 1 Fuse Resistor 1/2 W 47 K, 1/2 W 10 , 1/4 W 100 , 1/4 W Part Number 5GAS10 DD222 ECA-1EFQ271 ECE-A1EGE101 ECE-A1AGE470 ECU-S1H104MEA ECU-S1H104MEA UF4005 1N5822 1N4148 622LY-3R3M BW1/2F 1 5% 5053CX47K00J 5043CX10R00J 5043CX100R0J TRD7 TOP221P or TOP221G*** LTV817A 1N5228C Manufacturer Cera-Mite Philips Panasonic Panasonic Panasonic Panasonic Panasonic General Instrument General Instrument Liteon Toko RCD Philips Philips Philips Custom Power Integrations Liteon APD
Optocoupler, Controlled CTR 3.9 V, Zener, 2%
Table 2. Parts List For the RD7. (* Optional, for Css values see Figure 9. **T1 is available from Premier Magnetics (714) 362-4211 as P/N TDS-1185-9818, and from Coiltronics (561) 241-7876 as P/N CTX14-14193-X1. *** TOP221G can be used with layout modifications.)
General Circuit Description
The RD7 is a low-cost, flyback switching power supply using the TOP221P. The circuit shown in Figure 2 provides a nominal output power of 3.5 W at 5 VDC output. The power supply operates from a DC voltage of 90 to 375 VDC. In a typical application this DC voltage is derived from a rectified and filtered AC main voltage of 85 to 265 VAC. The 5 V output is directly sensed by optocoupler U2 and Zener diode VR1. The output voltage is determined by the Zener diode (VR1) voltage and the voltage drop across the optocoupler (U2) LED and resistor R2. Other output voltages are possible by adjusting the transformer turns ratios and the value of the Zener diode VR1. The positive rail of the high voltage DC input is connected to one side of the primary winding of T1. Capacitor C1 filters the high voltage supply, and is necessary only if the connections between the high voltage DC supply and the RD7 are long. The other side of the transformer primary is driven by the integrated, high-voltage MOSFET inside the TOP221. D1, R1, and C2 clamp voltage spikes caused by transformer leakage inductance to a safe value and reduce ringing at the DRAIN of U1. The secondary winding is rectified and filtered by D2 and C3 to generate a 5 V output. L1 and C4 provide additional filtering to reduce high frequency ripple voltage. R3 and VR1 provide a slight pre-load on the 5 V output to improve load regulation at light loads. R3 also provides bias current for Zener VR1 to improve regulation. Soft start can be added to eliminate turn-on overshoot. With Css placed across VR1, the optocoupler current is increased during turn-on time. This increased current limits the duty cycle and slows down the rising output voltage (See Figure 9). The bias winding output is rectified and filtered by D3 and C6 to provide a bias voltage for U2. C5 filters internal MOSFET gate drive charge current spikes on the CONTROL pin, determines the auto-restart frequency, and compensates the control loop. Cc is needed when the supply is operating in a noisy environment (e. g. when the power supply is sharing the same input rectifier and filter capacitor with another power supply). Cc filters high frequency noise. The schematic of Figure 4 shows an enhanced version of the RD7. The circuit comprising R2, R3, R4, R5 and U3 improves overall output regulation to 2%. Optional soft start capacitor Css is used to eliminate turn-on overshoot. The bias supply output can be used to provide a +12 V, non-isolated output by changing C6 to 100 F as shown in Figure 4. C6 is added to reduce output ripple to a primary load. The circuit performance data shown in Figures 5 to 12 was
B 4/99
3
RD7
T1 C2 2.2 nF 1 KV D2 1N5822 C3 270 F 25 V L1 3.3 H C4 100 F 25 V
+
5 V - 2% 0.6 A
+
RF1 1
R1 47 k
C1 10 nF 1 KV D1 UF4005 C6 D3 100 F 1N4148 35 V R3 75 R4 10 k
D
Fusible 90-375 VDC Input
U2 PC817A
TOPSwitch-II
CONTROL
C
R2 150
S
TOP221P U1 CC* 0.1 F C5 47 F 10 V
* CSS
U3 TL431
R5 10 k
+
12 V Non-isolated 50 mA
* optional component, not populated
PI-2189-071098
Figure 4. Schematic diagram of the RD7 with 12V Non-isolated output.
measured with DC voltage applied to RD7. Load Regulation (Figure 5(a) and 5(b)) - The amount of change in the DC output voltage for a given change in output current is referred to as load regulation. The 5 V output stay within 1.0% when the output current is between 0% to 100% of rated load current at the 5 V output. The TOPSwitch-II overtemperature protection circuit will safely shut down the power supply under prolonged overload conditions. When the output load is disconnected, R3 acts as a preload and the output stays in regulation. Line Regulation (Figure 6(a) and 6(b)) - The amount of change in DC output voltage for a given change in the DC input voltage is called line regulation. The maximum change in output voltage is within 1%. Efficiency (Line Dependent). Efficiency is the ratio of output power to the input power. The curve in Figure 7 shows how the efficiency changes with input voltage using a 3.5 W load. The efficiency is greater than 72% throughout the input range. Efficiency (Load Dependent). The curves in Figure 8 show how the efficiency changes with output power at 155 and 310 VDC inputs. The efficiency is greater than 70% for loads greater than 2.5 W.
Power Supply Turn On Sequence. An internal switched, high voltage current source provides the initial bias current for TOPSwitch when power is first applied. The waveforms shown in Figure 8 illustrates the timing relationship between the high voltage DC bus and 5 V output voltage for the RD7 circuit. Capacitor C1 charges to the DC input voltage before TOPSwitch turns on. The delay of 130 ms (typical) is caused by the time required to charge the auto-restart capacitor C5 to 5.7 V. At this point the power supply turns on as shown. Figure 10 shows the output voltage turn on transient as well as a family of curves associated with the additional soft-start capacitor Css. The soft-start capacitor is placed across VR2 and can range in value from 10 F to 47 F as shown. Switching frequency ripple voltage is shown in Figure 11 for the RD7 circuit at 155 VDC input and 3.5 W output. Peak to peak ripple is less than 50 mV at 3.5 W. The RD7 power supply transient response to a step load change from 0.52 A to 0.75 A (75% to 100%) is shown in Figure 12. The response is quick and well damped. The RD7 is designed to meet worldwide safety specifications.
4
B 4/99
RD7
Thermal Considerations The RD7 utilizes the printed circuit copper for TOPSwitch-II heatsinking. With a copper area of approximately 0.227 in2 (1.46 cm2 ) and 2 oz. (610 g/m2) copper cladding, the temperature of the TOPSwitch-II rises 6 oC at 50 oC ambient temperature and 3.5 W load. winding. The use of triple insulated wire allows the transformer to be constructed using a smaller core and bobbin than a conventional magnet wire design due to the elimination of the creepage margins required for safety spacing in a conventional design. If a conventional margin wound transformer is desired, the design of Figures 15 and 16 can be used. This design (TRD7-1) uses an EEL16 core and bobbin to accommodate the 6 mm creepage required to meet international safety standards when using magnet wire rather than triple insulated wire, and has the same pinout and printed circuit foot print as TRD7. The transformer is approximately 50% taller than the triple insulated wire design due to the inclusion of creepage margins required to meet international safety standards.
Transformer Specifications
The electrical specifications and construction details for transformer TRD7 are shown in Figures 13 and 14. Transformer TRD7 is supplied with the RD7 reference design board. This design utilizes an EE16 core and a triple insulated wire secondary
PI-2231-071098
Output Voltage (% of Nominal)
100
Output Voltage (% of Nominal)
VIN = 155 VDC
100
95
0
100
200
300
400
500
600
700
95
80
240
400
(a) 5 V Load Current (mA)
105 VIN = 310 VDC 100
(a) Input Voltage (VDC)
105
100
95
0
100
200
300
400
500
600
700
95
80
240
400
(b) 5 V Load Current (mA) Figure 5 (a). Load Regulation at 155 VDC Input Voltage. (b). Load Regulation at 310 VDC Input Voltage.
(b) Input Voltage (VDC)
Figure 6 (a). Line Regulation at 3.5 W Output. (b). Line Regulation at 0.35 W Output.
Efficiency (%)
70 60 50 40
Po = 3.5 W
30
80
240
400
Input Voltage (VDC)
Figure 7. Efficiency vs. Input Voltage, 3.5 W Output.
PI-2235-062998
80
PI-2233-071098
105
105
B 4/99
5
RD7
Efficiency (%)
60 40 20 0 VIN = 155 VDC VIN = 310 VDC 0.0 0.5 1.0 1.5 2.0 2.5 3.0
3.5
Output Power (W) Figure 8. Efficiency vs. Output Power.
PI-2239-060498
PI-2237-060398
80
DC BUS VOLTAGE
150 100 50 0 4 2 0
6 0 F
Output Voltage (V)
5 4 3 2 1 0
10 F 22 F 47 F
OUTPUT VOLTAGE
0
100
200
0
10
20
Time (ms)
Time (ms)
Figure 9. Turn on Delay.
Figure 10. Output Voltage Turn On Transient vs. Soft Start Capacitor.
Output Current (mA) Output Voltage (mV)
PI-2243-062998
150
50 0 - 50
Output Voltage (mV)
100 50 0 -50 -100 -150 -200 0 25
600 400 200 0 0 10 20
50
Time (s)
Time (ms)
Figure 11. Switching Frequency Ripple, 155 VDC Input, 3.5 W Output.
Figure 12. Transient Load Response (75% to 100% of load).
6
B 4/99
PI-2245-071098
200
100
PI-2241-060498
RD7
TRIPLE INSULATED SECONDARY TRANSFORMER (TRD1)
1 4 116 T #37 AWG 2 3 14 T #37 AWG 4 9, 10 6T #26 AWG Triple-insulated 6, 7 5
PIN
1 2 3 4 6, 7 9, 10
FUNCTION
HIGH-VOLTAGE DC BUS TOPSwitch DRAIN PRIMARY-SIDE COMMON VBIAS SECONDARY RETURN OUTPUT
1
10
CORE# - PC40 EE16-Z (TDK) GAP FOR AL OF 182 nH/T2 BOBBIN# - YW-193 (Yih Hwa Enterprises)
ELECTRICAL SPECIFICATIONS
Electrical Strength Creepage Primary Inductance Resonant Frequency Primary Leakage Inductance 60 Hz, 1 minute, from pins 1-4 to pins 5-10 Between pins 1-4 and pins 5-10 All windings open All windings open Between pins 1-2 (pins 6-10 shorted) 3000 VAC 6.00 mm (min) 2430 H -10% 500 kHz (min) 63 H (max)
NOTE: All inductance measurements should be made at 100 kHz
PI-2273-070298
Figure 13. Electrical Specification of Transformer TRD7.
B 4/99
7
RD7
TRIPLE INSULATED SECONDARY TRANSFORMER CONSTRUCTION
TAPE
{ {
TAPE
6, 7 9, 10 3 4 1 2
SECONDARY BIAS PRIMARY
WINDING INSTRUCTIONS
Primary Start at Pin 2. Wind one complete layer (about 58 turns) of 37 AWG heavy nyleze wire from left to right. Insulate first layer using 1 turn of polyester film tape, 8.3 mm wide, 0.056 mm thick. Wind remaining 58 turns from right to left for a total of 116 turns. Finish at Pin 1. Apply 1 layer of tape for basic insulation. Start at Pin 4. Wind 14 turns parallel bifilar of 37 AWG wire from left to right in a single layer. Finish at Pin 3. Apply 1 layer of tape for basic insulation. Start at Pins 9, 10. Wind 6 turns parallel bifilar of 26 AWG triple insulated wire from left to right. Finish on Pin 6, 7. Apply 3 layers of tape for basic insulation. Assemble and secure core halves. Impregnate uniformly with varnish.
Basic Insulation Bias Winding
Basic Insulation Secondary Winding
Outer Insulation Final Assembly
* Triple insulated wire sources. P/N: T27A01TXXX-3 Rubudue Wire Company 5150 E. La Palma Avenue Suite 108 Anaheim Hills, CA 92807 (714) 693-5512 (714) 693-5515 FAX P/N: order by description Furukawa Electric America, Inc. 200 Westpark Drive Suite 190 Peachtree City, GA 30269 (770) 487-1234 (770) 487-9910 FAX P/N: order by description The Furukawa Electric Co., Ltd 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 100, Japan 81-3-3286-3226 81-3-3286-3747 FAX
PI-2275-070298
Figure 14. Construction Details of Transformer TRD7.
8
B 4/99
RD7
MARGIN WOUND TRANSFORMER
1 116 T #35 AWG 2 3 14 T 35 AWG 4
10
5
9, 10 6T #26 AWG 6, 7
PIN
1 2 3 4 6, 7 9,10
FUNCTION
HIGH-VOLTAGE DC BUS TOPSwitch DRAIN PRIMARY-SIDE COMMON VBIAS RETURN OUTPUT
1 4
CORE# - PC40 EE16/24/5-Z (TDK) GAP FOR AL OF 182 nH/T2 BOBBIN# - YW-035 (Yih Hwa Enterprises)
ELECTRICAL SPECIFICATIONS
Electrical Strength Creepage Primary Inductance Resonant Frequency Primary Leakage Inductance 60 Hz, 1 minute, from pins 1-4 to pins 5-10 Between pins 1-4 and pins 5-10 All windings open All windings open Between pins 1-2 (pins 6-10 shorted) 3000 VAC 6.0 mm (min) 2430 H -10% 300 kHz (min) 70 H (max)
NOTE: All inductance measurements should be made at 100 kHz
PI-2277-062998
Figure 15. Electrical Specification of Transformer TRD7-1.
B 4/99
9
RD7
MARGIN WOUND TRANSFORMER CONSTRUCTION
TAPE MARGINS (4 PLACES) SECONDARY BIAS PRIMARY
TAPE
{
{
6, 7 9, 10 3 4
TAPE
1 2 SLEEVING
WINDING INSTRUCTIONS
Safety Margin Construct margins on each side of bobbin using 3 mm wide tape. Match height of primary plus bias winding. Start at Pin 2. Wind one complete layer (about 58 turns) of 35 AWG heavy nyleze wire from left to right between margins. Insulate first layer using 1 layer of polyester tape (polyester film 11.5 mm (0.456 in) wide and 0.056 (2.2 mil) thick) for basic insulation. Wind remaining 58 turns in second layer from right to left. Finish on Pin 1. Sleeve start and finish leads using safety approved insulating sleeving with 0.4 mm (0.016 in) minimum wall thickness. Apply 1 layer of 11.5 mm wide tape for basic insulation. Start at Pin 4. Wind 14 parallel bifilar turns of 35 AWG heavy nyleze wire from left to right in a single layer. Finish on Pin 3. Sleeve start and finish leads as above. Apply 3 layers of tape (polyester film, 17.5 mm (0.689 in) wide and 0.056 mm (2.2 mil) thick) for reinforced insulation. Construct margins on each side of bobbin using 3 mm wide tape. Match height of secondary winding. Start at Pin 9 and 10. Wind 6 parallel bifilar turns of 26 AWG heavy nyleze wire from left to right in a single layer. Finish on Pin 6 and 7. Sleeve start and finish leads as above. Apply 3 layers of 17.5 mm tape for outer insulation. Assemble and secure core halves. Impregnate uniformly with varnish.
PI-2281-062998
Primary
Basic Insulation Bias Winding
Reinforced Insulation
Safety Margin
Secondary Winding
Outer Insulation Final Assembly
Figure 16. Contruction Details of Transformer TRD7-1.
10
B 4/99
RD7
B 4/99
11
RD7
Revision Notes A B Measurement method for primary leakage inductance of TRD7 and TRD7-1 corrected. Date 9/98 4/99
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. PI Logo and TOPSwitch are registered trademarks of Power Integrations, Inc. (c)Copyright 1998, Power Integrations, Inc. 477 N. Mathilda Avenue, Sunnyvale, CA 94086 http://www.powerint.com
WORLD HEADQUARTERS NORTH AMERICA - WEST Power Integrations, Inc. 477 N. Mathilda Avenue Sunnyvale, CA 94086 USA Main: +1*408*523*9200 Customer Service: Phone: +1*408*523*9265 Fax: +1*408*523*9365 NORTH AMERICA - EAST & SOUTH AMERICA Power Integrations, Inc. Eastern Area Sales Office 1343 Canton Road, Suite C1 Marietta, GA 30066 USA Phone: +1*770*424*5152 Fax: +1*770*424*6567 EUROPE & AFRICA Power Integrations (Europe) Ltd. Centennial Court Easthampstead Road Bracknell Berkshire RG12 1YQ, United Kingdom Phone: +44*1344*462*300 Fax: +44*1344*311*732 TAIWAN Power Integrations International Holdings, Inc. 2F, #508, Chung Hsiao E. Rd., Sec. 5, Taipei 105, Taiwan Phone: +886*2*2727*1221 Fax: +886*2*2727*1223
KOREA Power Integrations International Holdings, Inc. Rm# 402, Handuk Building, 649-4 Yeoksam-Dong, Kangnam-Gu, Seoul, Korea Phone: +82*2*568*7520 Fax: +82*2*568*7474
JAPAN Power Integrations, K.K. Keihin-Tatemono 1st Bldg. 12-20 Shin-Yokohama 2-Chome, Kohoku-ku, Yokohama-shi, Kanagawa 222, Japan Phone: +81*(0)*45*471*1021 Fax: +81*(0)*45*471*3717
INDIA (Technical Support) Innovatech #1, 8th Main Road Vasanthnagar Bangalore 560052, India Phone: +91*80*226*6023 Fax: +91*80*228*2191
APPLICATIONS HOTLINE World Wide +1*408*523*9260 APPLICATIONS FAX World Wide +1*408*523*9361
12
B 4/99

▲Up To Search▲

Price & Availability of RD7

	To Download RD7 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .