POWER RD2 Datasheet

RD2

TOPSwitch

Reference Design Board

85 to 132 VAC or 170 to 265 VAC Input, 8W(10W Peak) Output

Product Highlights

Low Cost Production Worthy Reference Design

• Only 21 components!

• Single sided board

• Low cost thru-hole components

• Fully assembled and tested

• Easy to evaluate and modify

• Extensive performance data

• Up to 77% efficiency

• Light weight - no heat sink required for TOPSwitch

®

1.4 in.

2.6 in.

Fully Protected by

• Primary safety current limit

• Output short circuit protection

• Thermal shutdown protects entire power supply

Designed for World Wide Operation

• Designed for IEC/UL safety requirements

• Meets VDE Class B EMI specifications

Typical Applications

• Replacement for low power linear adapters

• Auxiliary power supply for appliance, motor control, utility meters, smart building, UPS, etc.

TOPSwitch

Description

The RD2 reference design board is an example of a very low cost production worthy power supply design using the TOPSwitch family of Three-terminal Off-line Switchers from Power Integrations. It is intended to help TOPSwitch users to quickly develop their products by providing a basic design that can be easily modified to fit a particular application. In most cases, a minor change to the transformer for a different output voltage or voltages is all that is needed. A complete set of performance curves, the parts list, the board layout and details on transformer design are provided to speed up the TOPSwitch based switcher design.

0.8 in.

Figure 1. RD2 Board Overall Physical Dimensions.

PARAMETER LIMITS

Input Voltage Range Input Frequency Range 47 to 440 Hz Temperature Range 0 to 70°C Output Voltage (I = 0.67A) 12 V ± 10% Output Power (continuous) 8 W Output Power (peak) 10 W Line Regulation ± 0.7% Load Regulation (10%-100%) ± 5% Efficiency (115 V input, 8 W out) 75% Output Ripple Voltage ± 50 mV MAX

(85-132 VAC) (170-265 VAC)

85 to 132 VAC

or 170 to 265 VAC

PI-1768-020596

Safety IEC 950 / UL1950 EMI

Figure 2. Table of Key Electrical Parameters.

VDE B (VFG243 B)

CISPR22

May 1996

RD2

47nF

250VAC

F1 2A

BR1

DF06M

JUMPER

8 mH

0.2A

470 KΩ

JP1*

470 KΩ

C9 10 µF 200 V

VR1

BZY97-C200

10 µF 200 V

UF4005

6.8 Ω

47 µF

TOP

210

10 V

* JPI CLOSED FOR 115 VAC INPUT

JPI OPEN FOR 230 VAC INPUT

1N4148

250 VAC

1nF

T1RD2

MBR360

330 µF

16 V

3.3 µH C3

120 µF

16 V

12 V

390 Ω

RTN

PI-1783-020596

Figure 3. Schematic Diagram of the RD2 Power Supply.

CAUTION

The RD2 features a 115/230 VAC selectable input, and is shipped configured for 230 VAC operation (JP1 open). If JP1 is used for 115 VAC operation, it must be removed before applying 230 VAC.

F1 C1

TOPSwitch

BR1

RD2

JP1

C9 8

VR1

D3 T1

L1+

PI-1817-040296

Figure 4. Component Legend of the RD2.

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Component Listing

Reference Value Part Number Manufacturer

U1 TOP210PFI Power Integrations D1 600V, 1A, UFR UF4005 General Instruments D2 Schottky, 3A, 60V MBR360 Motorola D3 75 V Switching 1N4148 Rohm BR1 1 A, 600 V DF06M General Instruments VR1 200 V Zener, 1.5 W BZY97-C200 SGS/Thomson, Fagor L1 3.3 µH, 4A Custom L2 8 mH, 0.2A SU9V-02080 Tokin C1, C9 10 µF, 200V KMG200VB10RM10X16 United Chemicon C2 330 µF, 16V LXF16VB331M8X15 United Chemicon C3 120 µF, 16V LXF16VB121M6.3X11.5 United Chemicon C5 47 µF, 10V KME10VB47RM5X12.5 United Chemicon C6 47 nF, 250 VAC, X 2 F1772-347-2000 Roederstein C7 1 nF, 250 VAC, Y1 RA, RB 470 K, 1/4 W 5043CX470K0J Philips R1 6.8 Ω, 1/4 W 5043CX6R800J Philips R2 390 ohms, 1 W MO-1 391J Koa/Speer T1 Custom T1RD2 F1 2A, 250 VAC 19372, 2A Wickman

DE1110 E 102M ACT4K-KD

RD2

Murata

Figure 5. Parts List for the RD2.

General Circuit Description

The RD2 is a low-cost, isolated Buck-Boost or flyback switching power supply using the TOP210 integrated circuit. The circuit shown in Figure 3 produces a 12 V, 8 W power supply that operates from 85 to 132 VAC or 170 to 264 VAC input voltage. The 12 V output voltage is determined by the TOPSwitch control pin shunt regulator voltage, the voltage drop of D3, and the turns ratio between the bias and output windings of T1. Other output voltages are also possible by adjusting the transformer turns ratios. R1 and C5 provide filtering of the bias winding to improve line and load regulation.

AC power is rectified and filtered by BR1, C1 and C9 to create the high voltage DC bus applied to the primary winding of T1. The other side of the transformer primary is driven by the integrated high-voltage MOSFET inside the TOP210. JP1 is a jumper used to select 115 V or 230 V operation. Adding JP1 selects 115 V operation. Leaving JP1 open selects 230 V operation. RD2 is supplied with JP1 open. RA and RB equalize leakage currents between C1 and C9. D1 and VR1 clamp the leading-edge voltage spike caused by transformer leakage inductance to a safe value and reduce ringing. The power secondary winding is rectified and filtered by D2, C2, L1, and

C3 to create the 12 V output voltage. R2 provides a pre-load on the 12 V output to improve load regulation at light loads. The bias winding is rectified and filtered by D3, R1, and C5 to create a bias voltage to the TOP210. Common-mode EMI currents which flow between the primary windings of the transformer and the secondary output circuitry are attenuated by L2 and C7. Differential-mode EMI currents caused by pulsating currents at the input of the power supply are attenuated by C6 and L2. C5 filters the internal MOSFET gate drive charge current spikes on the Control pin, determines the auto-restart frequency, and together with R1, compensates the control loop.

The circuit performance data shown in Figures 6-18 was measured with AC voltage applied to the RD2.

Load Regulation (Figure 6) - The amount of change in the DC output voltage for a given change in output current is referred to as load regulation. The 12 V output stays within ±5% from 10% to 100% of rated load current. The TOPSwitch on-chip overtemperature protection circuit will safely shut down the power supply under sustained overload conditions.

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RD2

General Circuit Description (cont.)

Line Regulation (Figure 7) - The amount of change in the DC output voltage for a given change in the AC input voltage is called line regulation. The maximum change in output voltage is less than ±0.7%.

Efficiency (Line Dependent) - Efficiency is the ratio of the output power to the input power. The curves in Figures 8 and 9 show how the efficiency changes with input voltage. Curves are also given to show the difference in efficiency when C1 and C9 are changed from 10 µF to 22 µF.

Efficiency (Load Dependent) - The curves in Figures 10 and 11 show how the efficiency changes with output power at 115 and 230 VAC inputs. The curves also show the increase in efficiency when C1 and C9 are changed from 10 µF to 22 µF.

Power Supply Turn On Sequence - The internal switched, highvoltage current source provides the initial bias current for TOPSwitch when power is first applied. The waveforms shown in Figure 12 illustrate the relationship between the high-voltage

DC bus and 12 V output voltage. Capacitors C1 and C9 charge to the peak of the AC input voltage before TOPSwitch turns on. The delay of 150 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 13 shows the output voltage turn on transient.

Line frequency ripple voltage is shown in Figure 14 for 115 VAC input and 8W output. Switching frequency ripple voltage is shown in Figure 15 for the same test condition.

The power supply transient response to a step load change from

0.5 A to 0.67 A (75% to 100%) is shown in Figure 16. Note that the response is quick and well damped.

The RD2 is designed to meet worldwide safety and EMI (VDE B) specifications. Measured conducted emissions are shown in Figure 17 for 115 VAC and Figure 18 for 230 VAC.

105

100

200 300

VIN = 115 VAC

PI-1769-020596

400 500 600 700

Load Current (mA)

105

100

Output Voltage (% of Nominal)

100

200 300

VIN = 230 VAC

400 500 600 700

Load Current (mA)

Figure 6. Load Regulation Figure 7. Line Regulation

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101

100.5 100

99.5 99

90 100 110 120 130

Input Voltage (VAC)

101

100.5 100

Output Voltage (% of Nominal)

99.5 99

= 0.67 A

OUT

= 0.17 A

OUT

180 200 220 240 260

Input Voltage (VAC)

OUT

= 0.67 A = 0.17 A

PI-1770-020596

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