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CRD1615A-8W-125V Schematic

AN402

Design Example of CS1615A

for 8.5W Dimmer-Compatible SSL Circuit

Features

• Supports Cirrus Logic CS1615A

• Quasi-resonant Buck-Boost Topology with Constant-

current Output

• Flicker-free Dimming

• Line Voltage: 108VAC -132VAC

• Rated Input Power: 8.5W

• Rated Output Power: 7.83W

• Efficiency: ~88% at 58mA for 42xLEDs in Series

• Low Component Count

General Description

This application note provides an example of a Solid State

Lighting (SSL) LED lamp circuit designed using Cirrus

Logic’s CS1615A, the CRD1615A-8W-125V. The

CRD1615A-8W-125V reference design demonstrates the

performance of the CS1615A resonant mode AC/DC LED

driver IC with a 58mA output driving

42xLEDs in series

. It

offers best-in-class dimmer compatibility and minimum

dimming performance with leading-edge, trailing-edge, and

digital dimmers. The form factor is targeted to fit into many

LED bulb applications (A19-type, PAR).

AUG‘14

AN402

Summary of content (14 pages)

PAGE 1
AN402 Design Example of CS1615A for 8.5W Dimmer-Compatible SSL Circuit Features General Description • Supports Cirrus Logic CS1615A This application note provides an example of a Solid State Lighting (SSL) LED lamp circuit designed using Cirrus Logic’s CS1615A, the CRD1615A-8W-125V. The CRD1615A-8W-125V reference design demonstrates the performance of the CS1615A resonant mode AC/DC LED driver IC with a 58mA output driving 42xLEDs in series.
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AN402 IMPORTANT SAFETY INSTRUCTIONS Read and follow all safety instructions prior to using this demonstration board. This Engineering Evaluation Unit or Demonstration Board must only be used for assessing IC performance in a laboratory setting. This product is not intended for any other use or incorporation into products for sale. This product must only be used by qualified technicians or professionals who are trained in the safety procedures associated with the use of demonstration boards.
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AN402 1. INTRODUCTION The CS1615A is a 120VAC quasi-resonant buck-boost mode dimmable LED controller IC. The CS1615A uses a digital control algorithm that is optimized for high efficiency and > 0.90 power factor over an input voltage range (108VAC -132VAC). The CS1615A integrates a dimmer compatibilty circuit with a constant output current, quasiresonant flyback stage.
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2. SCHEMATIC AN402 Figure 1.
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AN402 3. BILL OF MATERIALS Ref BR1 C1 C2 C3 C4 C5 C6 C7 C8 C12 D1, D2, D4, D8 D6 D7 F1 L1 NTC Q1 Q2 Q3 R1 R2, R3 R5 R6 R8 R9 R10 R12 R13 R14 R15 R16 TR1 U1 VZ Descript DIODE RECT 200V 0.8A NPB MINIDIP CAP FILM 0.047UF 250VDC RADIAL CAP FILM 0.068UF 250VDC RADIAL CAP FILM 0.15UF 250VDC RADIAL CAP CER 1UF 25V 10% X7R 0805 CAP CER 0.
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4. BOARD LAYOUT Figure 2.
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Figure 3.
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Figure 4.
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Figure 5.
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AN402 5. DIMMER COMPATIBILITY A19 Lamp with a CS1615A (120V/60Hz) Date 11/20/2013 Power Factor1,4 Vendor Cirrus Logic EN55015 Compliant (Y/N) Input Voltage 1,4 Maximum Input Power (W) CRD1615A-8W-125V IC CS1615A Topology N Efficiency (%) 87.5% Dimmer 5 Manufacture Type Output Voltage (V) 11 1,2 Output Current (mA) 36V 1,2 250 Output Current Ripple  120Hz Buck-Boost Isolation (Y/N) 10.57 Nominal Input Power (W) N/A Model # N 1,4 120V/60Hz Form Factor 0.
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AN402 Dimmer 5 Manufacture Type Flicker Free Steady-State Monotonic Dimming Max Iout (mA) Min Iout (mA) # of lamps # of lamps # of lamps # of lamps 1 1 1 1 Lutron AD-600M Leading Edge Y Y 58 1 Lutron AY-600P Leading Edge Y Y 58 1 Lutron CT-600P Leading Edge N Y 58 1 Lutron CT-603PG Leading Edge N Y 46 1 Lutron CTCL-153P Leading Edge Y Y 58 1 Lutron DVCL-153P Leading Edge Y Y 58 1 Lutron DVELV-300P Trailing Edge Y N 52 1 Lutron DVW-603PG Leading Edge
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AN402 6. PERFORMANCE PLOTS 0.06 LED Current (A) 0.055 0.05 0.045 0.04 108 110 112 114 116 118 120 122 124 126 128 130 132 Link Voltage (V) Figure 6. Output Current vs. Line Voltage 100 98 96 Efficiency(%) 94 92 90 88 86 84 82 80 108 110 112 114 116 118 120 122 124 126 128 130 132 Link Voltage (V) Figure 7. Typical Efficiency vs.
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AN402 1 0.995 0.99 0.985 Power Factor 0.98 0.975 0.97 0.965 0.96 0.955 0.95 108 110 112 114 116 118 120 122 124 126 128 130 132 Line Voltage (V) Figure 8. Power Factor vs.
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AN402 7.