UM10406

UM10406 NXP | Alldatasheet

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SSL1523 high power factor 5 W LED driver for universal mains Rev. 01 — 3 August 2010 User manual Document information Info Content Keywords SSL1523, SSL152x family, LED driver, mains supply, AC/DC conversion Abstract This user manual describes a demonstration (demo) board for a mains operated non-dimmable 5 W LED driver using the SSL1523 SMPS controller IC.

User manual Rev. 01 — 3 August 2010 2 of 21 Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com NXP Semiconductors UM10406 SSL1523 5 W LED driver

Revision history

1.1 General description

Table 1 shows the specification for the SSL1523 5 W LED driver. risk of electric shock, personal injury, death and/or ignition of fire. Table 1. Specification

120 V (AC) ± 10 % variation

130 V (AC) ± 1

210 V (AC) to 254 V (AC)

see graphs Figure 9 and Figure 10.

Table 1. Specification …continued

User manual Rev. 01 — 3 August 2010 5 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver 4. Demo board connections The demo board can be operated from mains voltages of 120 V (AC) (60 Hz) up to 230 V (AC) (50 Hz). The board is designed to work with multiple high power LEDs with a total working voltage of 12 V to 25 V. The output current can be set by resistor R18, see Section 7 . A dedicated LED load connected to K3 can be supplied on request. The connector K2 can be used to attach other LED loads. The output voltage is limited to a maximum of 33 V. When attaching a LED load to an operational board (hot plugging), an inrush peak current will occur due to discharge of capacitor C10. After (some) discharge(s), the LEDs may deteriorate and/or become damaged.

4.1 Connecting the demo board:

• If a galvanic isolated transformer is used, this should be placed between the AC source and the demo board.
• Connect a user-defined LED (string) to the connector K2 as shown in Figure 3. Make sure that the anode of the LED (string) is connected to + (bottom side of this connector). 5. Functional description The SSL1523 IC (Ref. 3) has several internal functions which include the following:
• The SSL1523 controls and drives the flyback converter.
• Over Current Protection (OCP) of the internal FET at 0.5 V on the SOURCE pin.
• The converter frequency is set with an internal oscillator, the timing of which is controlled by external RC components on pin RC.
• The REG pin controls the on-time of the internal switch between 0 % and 75 %. This board is optimized to operate at a power factor of 0.9 in the nominal application with six LEDs on the output. In order to achieve this, the converter operates dominantly at a constant ton mode. The output power of the converter is buffered by capacitor C10, and therefore the circuit exhibits resistive input current behavior (see Figure 4). Fig 3. Demo board connection diagram K3 J1 J2 pin 1: LED + pin 6: LED − pin 5: LED − pin 4: LED − pin 3: LED + pin 2: LED + pin 1: LED + pin 2: LED − 019aaa134 pin 2: − pin 1: + pin 3: N pin 1: L pin 2: control input from external opto coupler

User manual Rev. 01 — 3 August 2010 6 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver The input circuit of the converter must be equipped with a filter that is partially capacitive, in order to address the EMC requirements (see Figure 5). The combination of C1, L1 and C2 make a filter that blocks most of the disturbance generated by the converter input current. This filter is designed to have a limited capacitive load, so a good power factor can be achieved. For this design, two 150 nF capacitors are incorporated, resulting in a power factor of at least 0.9 for the nominal condition with six LEDs connected at 5 W output power. The board is equipped with a feedback loop to regulate the output current. This feedback loop senses the LED current over sense resistor R10, and a current mirror is made from transistors Q10a/Q10b. Using R18, the current level can then be set. The same feedback loop is also used to provide overvoltage protection. If the LED voltage exceeds 33 V, a current through R17 and D11, D12 and D13 will start running. The current through the opto coupler IC2 will pull up the REG pin. At values above 2.7 V, the ‘on time’ of the internal MOSFET is zero. The feedback loop has a proportional, and partially integrated action. The gain is critical due to the phase shift caused by the converter and the output capacitor C10. Increased gain will make the feedback loop intrinsically unstable. The accuracy of the resulting output current will satisfy the requirements of the majority of the 5 W LED applications with four to eight LEDs connected in series. The demo board can be controlled by connecting the floating output of an external opto coupler (TCDT1124 or equivalent) to K4. The demo board can be switched on and off by switching the external opto coupler. Controlling the LED current is another option. The LED current can be regulated by applying a PWM signal to the external input with a frequency up to 1 kHz. The PWM frequency can be synchronized with the ripple frequency on the buffer capacitor C1 for an optimal mains input current shape. Fig 4. Mains current (C2), V CC (C1), bulk capacitor input voltage (C3) and the mains voltage (C4) 019aaa135

User manual Rev. 01 — 3 August 2010 7 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver 6. Board system optimization To meet specific customer application requirements, the modifications described in the following sections are possible.

6.1 Changing the output current and LED current

One of the major advantages of a flyback converter over other topologies, is its suitability for driving LED configurations with a broad range of voltages. Essentially, changing the winding ratio whilst maintaining the value of the primary inductance, will shift the output working voltage accordingly. Part of the efficiency of the driver is linked to the output voltage. A lower output voltage will require increased transformation ratio, and will cause higher secondary losses. In practice, a mains operated flyback converter will have an efficiency > 80 % for high output voltages (like 40 V) down to 50 % for very low output voltages < 3 V. At low voltages, synchronous rectification becomes advisable to reduce rectification losses. The NXP TEA 1761/TEA1762 can be used for this purpose, see Ref. 1 . For exact calculations of transformer properties and peak current, refer to Ref. 2 application note AN10754, “How to design an LED driver using the SSL2101”, see Ref. 2.

6.2 Changing the output ripple current

The output ripple current is mostly determined by the LED voltage, the LED dynamic resistance and the output capacitor. The present value of C10 has been chosen to optimize the capacitor size under typical load. The resulting ripple of ± 30 % will result in an expected deterioration of light output < 1 %. The size for the buffer capacitor (C10) can be estimated from Equation 1: (1) Using a series of LEDs, the dynamic resistance of each LED can be multiplied by the number of LEDs. The current sense resistor (R10) should also be included in this calculation. Example: For a ripple current of ± 30 %, and a mains frequency of 50 Hz, and a total dynamic resistance of 7 Ω, the resulting capacitance value will be 3.3333 / (314*7) = 1500 μF. The capacitor must be specified for the HF switching related ripple current of about 0.35 times the average effective LED current (I LED(AV)). For high lifetime applications, the ripple current specification of the electrolytic capacitor must be increased. For details, please contact the capacitor supplier.

6.3 Changing the load curve

The current load curve can be divided into the following two regions:

• Where the current control loop regulates the output current, the constant current output
• Where the IC limits the peak input current of the converter, the constant power output C10 I

User manual Rev. 01 — 3 August 2010 8 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver The constant power output occurs at output voltages above 23 V combined with an output power exceeding 5 W, see also Section 9, Figure 9. In this area, constant output power becomes the dominant control mechanism. At very low output voltages, the feedback loop will become non-functional, resulting again in constant output power mode. An output short-circuit will cause an output current of about 1 A, resulting in increased stress on the transformer TX1, shunt resistor R10, the output diode D10, and the snubber diode D3.

xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx User manual Rev. 01 — 3 August 2010 9 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver 7. Board schematic Fig 5. Demo board schematic 019aaa136 SSL152X DRAIN HGND HGND HGND HGND HGND HGND SGND SGND C15 Y -Type D10 TX1 760871038-E13 L10 R10 C12 1 μF , 35 V R11 220 Ω R12 220 Ω R13 1 kΩ R14 10 kΩ R15 10 kΩ R20 10 kΩ 47 kΩ 100 Ω 33 Ω, 2 W FUSE TIME-LAG, 1A 1 mH 13R105C HER107 P6KE400A RMB6S 150 nF 400 V 150 nF

400 V D3

10 kΩ R18 4.7 kΩ R17 1 kΩ C13 6.8 μF R16 6.2 kΩ D11 BZV55-C22 Q10 BCM857DS,115 Q11 BC857 D12 1N4148W-V-GS08 D13 BZV55-C6v2 IC2 TCDT1124 1 Ω, 1 W K3-1 K3-2 K3-3 K3-4 K3-5 K3-6

12 V(DC)

25 V(DC)

10 μH, 2.6 A 744772100 C11 1 μF 35 V C10 1500 μF 35 V 2.4 Ω 20 kΩ 1 μF 35 V BZV55-C30 220 kΩ 330 pF 6.8 kΩ R8 2.4 Ω 120 kΩ SB1H100 1 nF , 250 V AC VCC 1 IC1 GND RC REG n.c. 8RC AUX CONTROL INPUT

120 V(AC)

230 V(AC)

7.1 Bill of materials (BOM)

Table 2. Bill of materials Description Value PCB footprint Supplier Art no. Manufacturer Manufacturer part no.

250 V (AC)

1. Transformer specification

Table 2. Bill of materials …continued

8.1 Winding specification

8.2 Electrical characteristics

• Nominal frequency = 100 kHz
• Vbreakdown N1, N2 = 4 kV and N3, N2 = 4 kV
• Leakage inductance = 20 μH (short N2)

8.3 Core and bobbin

• Core: EE13/6/6 (3C90 or better)
• Air gap in centre leg
• Bobbin: for EE13/6/6 core; bobbin must be suitable for Class II isolation requirements.

8.4 Physical dimensions

Table 3. Winding specification Table 4. Inductance

User manual Rev. 01 — 3 August 2010 13 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver 9. Appendix

9.1 Load curves

(1) LED current = 250 mA. (2) LED current = 200 mA. (3) LED current = 150 mA. Fig 9. 120 V (AC) load curve at V LED = 19.5 V (1) LED current = 250 mA. (2) LED current = 200 mA. (3) LED current = 150 mA. Fig 10. 230 V (AC) load curve at V LED = 19.5 V (1) (2) (3) 019aaa140 LED voltage (V) 12 28242016 175 225 275 LED current (mA) 125 019aaa141 LED voltage (V) 12 28242016 175 225 275 LED current (mA) 125 (3) (1) (2)

User manual Rev. 01 — 3 August 2010 14 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver

9.2 Efficiency curves

(1) LED current = 250 mA. (2) LED current = 200 mA. (3) LED current = 150 mA. Fig 11. 120 V (AC) efficiency curve (1) LED current = 250 mA. (2) LED current = 200 mA. (3) LED current = 150 mA. Fig 12. 230 V (AC) efficiency curve 019aaa142 LED voltage (V) 12 28242016 0.76 0.80 0.84 η (%) 0.72 (1) (2) (3) 019aaa143 LED voltage (V) 12 28242016 0.76 0.80 0.84 η (%) 0.72 (1) (3) (2)

User manual Rev. 01 — 3 August 2010 15 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver

9.3 Input voltage dependency

9.4 EMC requirements

(1) LED current set at 250 mA nominal with a load of six LEDs in series (19.5 V). Fig 13. Input voltage versus output current Umains (V) 70 270230150 190110 019aaa144 250 248 252 254 lout (mA) 246 (1) Fig 14. EMC measurements at a mains voltage of 120 V (AC) NXP Semiconductors 1P K MAXH 2 AV CLRWR SGL 6DB 9 kHz 30 MHz dBVdBV MT 1 ms RBW 9 kHz PREAMP OFFAtt 10 dB 04.Dec 09 17:52 100 kHz 1 MHz 10 MHz 100 Marker 1 [T2 ] 48.64 dBV 9.000000000 kHz FCC15AVQ FCC15BVQ 019aaa145

9.5 Mains conducted harmonics

Table 5. Mains conducted harmonics

for synchronous rectification. [2] AN10754 — How to design an LED driver using the SSL2101 or SSL2102. [3] SSL152x — Datasheet - SMPS ICs for mains LED drivers. Table 6. Total Harmonic Distortion and Power Factor

User manual Rev. 01 — 3 August 2010 18 of 21 NXP Semiconductors UM10406 SSL1523 5 W LED driver 11. Legal information

11.1 Definitions

Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information.

11.2 Disclaimers

Limited warranty and liability — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. In no event shall NXP Semiconductors be liable for any indirect, incidental, punitive, special or consequential damages (including - without limitation - lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory. Notwithstanding any damages that customer might incur for any reason whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms and conditions of commercial sale of NXP Semiconductors. Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof. Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical systems or equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Customers are responsible for the design and operation of their applications and products using NXP Semiconductors products, and NXP Semiconductors accepts no liability for any assistance with applications or customer product design. It is customer’s sole responsibility to determine whether the NXP Semiconductors product is suitable and fit for the customer’s applications and products planned, as well as for the planned application and use of customer’s third party customer(s). Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products. NXP Semiconductors does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer’s applications or products, or the application or use by customer’s third party customer(s). Customer is responsible for doing all necessary testing for the customer’s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer’s third party customer(s). NXP does not accept any liability in this respect. Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from national authorities. Evaluation products — This product is provided on an “as is” and “with all faults” basis for evaluation purposes only. NXP Semiconductors, its affiliates and their suppliers expressly disclaim all warranties, whether express, implied or statutory, including but not limited to the implied warranties of non-infringement, merchantability and fitness for a particular purpose. The entire risk as to the quality, or arising out of the use or performance, of this product remains with customer. In no event shall NXP Semiconductors, its affiliates or their suppliers be liable to customer for any special, indirect, consequential, punitive or incidental damages (including without limitation damages for loss of business, business interruption, loss of use, loss of data or information, and the like) arising out the use of or inability to use the product, whether or not based on tort (including negligence), strict liability, breach of contract, breach of warranty or any other theory, even if advised of the possibility of such damages. Notwithstanding any damages that customer might incur for any reason whatsoever (including without limitation, all damages referenced above and all direct or general damages), the entire liability of NXP Semiconductors, its affiliates and their suppliers and customer’s exclusive remedy for all of the foregoing shall be limited to actual damages incurred by customer based on reasonable reliance up to the greater of the amount actually paid by customer for the product or five dollars (US$5.00). The foregoing limitations, exclusions and disclaimers shall apply to the maximum extent permitted by applicable law, even if any remedy fails of its essential purpose.

11.3 Trademarks

Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners.

Table 6. Total Harmonic Distortion and Power Factor . .17

User manual Rev. 01 — 3 August 2010 20 of 21 continued >> NXP Semiconductors UM10406 SSL1523 5 W LED driver 13. Figures Fig 4. Mains current (C2), V CC (C1), bulk capacitor input voltage (C3) and the mains voltage (C4) . . .6 Fig 9. 120 V (AC) load curve at V Fig 14. EMC measurements at a mains voltage Fig 15. EMC measurements at a mains voltage

NXP Semiconductors UM10406 SSL1523 5 W LED driver © NXP B.V. 2010. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com Date of release: 3 August 2010 Document identifier: UM10406 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. 14. Contents 6.1 Changing the output current and LED current . 7