AMC7150 Reference Design AMC7150 – 1.5A Power LED Driver Content 1. AMC7150 EVM User Guide 2. Application of AMC7150 @ VIN=12VDC 3. Application of AMC7150 @ VIN=24VDC 4. Application of AMC7150 for MR16 5. PWM Dimming Function of AMC7150 6. Thermal Issue of AMC7150: Temperature vs. Current 7. Relationship between VIN and the LED Driving Current Copyright © 2006, ADDtek Corp. DA011 － September 1, 2006 www.micro-bridge.com AMC7150 1. AMC7150 EVM User Guide 1.1. Circuit Scheme: DC-IN Jack VCC VIN L Rsen D1 CS CIN + J1 OUT 1 DF AMC7150 J2 LED1 OSC LED2 4 GND CT 1.2. Picture: (Rsen) Set LED Peak Current Test Point DC-IN Jack (D1) Reverse Protection Diode (J1) Mode Selection Copyright © 2006, ADDtek Corp. 1-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 1.3. Description: 【1】 DC-IN: DC power jack. It is designed to provide convenience for demo. Simply one adapter is needed for supplying the EVM board to light up the Power LEDs. 【2】 D1: Reverse protection diode. It is located between input port of the EVM, VIN, and Vcc pin of the IC. The function is to provide protection when input source is reverse connected. 【3】 J1: Lighting mode selection connector. Four lighting modes of the 2 LEDs can be accomplished through jumper. The 2 LEDs can be connected in series or parallel, or either of the 2 LEDs can be selected. The method of selecting one of these modes is shown in the following table. Table Method of using jumper to select 1 of the 4 lighting modes for the 2 LEDs. Mode Lighting condition of LED1 and LED2 J1 1 LED1&LED2 connected in serial 1 2 3 4 2 LED1&LED2 connected in parallel 1 2 3 4 3 LED1 1 2 3 4 4 LED2 1 2 3 4 【4】 J2: Test point. It is reserved for current measurement to make sure that the LED driving current matches the value calculated by the formula below (Please refer to the datasheet for the calculated method of the average current): I PK = 330mV ± 10% Rsense 1.4. Reference PCB Layout: Top Layer Bottom Layer Large PCB area is reserved for GND plane and is connected to the heat pad of AMC7150. The GND plane can be a part of heat sink for AMC7150. Copyright © 2006, ADDtek Corp. DA011 － September 1, 2006 1-2 www.micro-bridge.com AMC7150 2. Application of AMC7150 @ VIN=12VDC 2.1. V IN =12V DC for 1pcs of Power LED: A. Circuit Diagram: B. Bill of Material: Component Value Package AMC7150 - TO-252-5L CIN 47uF / 16V E. C. Cap. CT DIP / SMD 0603 RSENSE 680~820pF 0.87Ω DF 1SS15C1 SOD-123 L 220uH - Copyright © 2006, ADDtek Corp. DIP / SMD 1206 2-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 2.2. V IN =12V DC for 2pcs of Power LED in Series: A. Circuit Diagram: B. Bill of Material: Component Value Package AMC7150 - TO-252-5L CIN 47uF / 16V E. C. Cap. CT DIP / SMD 0603 RSENSE 680~820pF 0.83Ω DF 1SS15C1 SOD-123 L 220μH - Copyright © 2006, ADDtek Corp. DIP / SMD 1206 2-2 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 2.3. V IN =12V DC for 3pcs of Power LED in Parallel: A. Circuit Diagram: B. Bill of Material: Component Value Package AMC7150 - TO-252-5L CIN 47uF / 16V E. C. Cap. CT DIP / SMD 0603 RSENSE 680~820pF 0.92Ω DF 1SS15C1 SOD-123 L 220uH - Copyright © 2006, ADDtek Corp. DIP / SMD 1206 2-3 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 3. Application of AMC7150 @ VIN=24VDC 3.1. V IN =24V DC for 2pcs of Power LED in Series: A. Circuit Diagram: B. Bill of Material: Component Value Package AMC7150 - TO-252-5L CIN 47uF / 35V E. C. Cap. CT DIP / SMD 0603 RSENSE 680~820pF 0.83Ω DF 1SS15C1 L 220uH SOD-123 - Copyright © 2006, ADDtek Corp. DIP / SMD 1206 3-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 3.2 V IN =24V DC for 3pcs of Power LED in Series: A. Circuit Diagram: B. Bill of Material: Component Value Package AMC7150 - TO-252-5L CIN 47uF / 35V E. C. Cap. CT DIP / SMD 0603 RSENSE 680~820pF 0.8Ω DF 1SS15C1 SOD-123 L 220uH - Copyright © 2006, ADDtek Corp. DIP / SMD 1206 3-2 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 4. Application of AMC7150 for MR16 4.1. Application Circuit of AMC7150 for MR16 (VIN=12VAC): L Rsense D1 D2 VCC 12Vac OSC CIN D4 CS Power LED OUT AMC7150 DF GND CT D3 4.2. Bill of Material: C. R. No. Q’TY Value PCB 1 - PCB－12V Ballast Solution 7150 for MR-16 IC 1 - AMC7150 CIN 1 47~100uF/25V D1~D4 4 1SS15C1 Schottky Diode【40V/1A】 DF 1 1SS15C1 Schottky Diode【40V/1A】 RSENSE 1 0.22Ω~3Ω SMD 0603 L1 1 220uH CT 1 680~820pF Copyright © 2006, ADDtek Corp. Description Tantalum Chip Cap. IDC=0.4 ~ 1.2A SMD 0603 4-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 5. PWM Dimming Function of AMC7150 5.1 Application Circuit： L Rsense 4V~40V VCC CS Power LED OUT 1N4148 OSC Enable CIN AMC7150 DF GND CT 5.2 Description of Enable Control： One diode (1N4148) is added between the inward PWM control signal and the OSC pin. Parameter Description Symbol Min Max Unit 2 5.5 V Enable voltage “High” Turn OFF the driver VEN,H Enable voltage “Low” Turn ON the driver VEN,L 0.4 V Enable voltage sink current Turn OFF the driver IEN 300 uA Apply Pin Enable 5.3 Measured Waveform： When ON duty=100%, iLED,Mean =369mA ON duty = 9.3%, iLED,Mean =30.2mA ON duty = 91.7%, iLED,Mean =342mA Ch1: iLED, Ch3: Enable Ch1: iLED, Ch3: Enable Copyright © 2006, ADDtek Corp. 5-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 6. Thermal Issue of AMC7150: Temperature vs. Current AMC7150 can work well under ambient temperature from -40℃ to +125℃. Put the AMC7150 EVM board into the programmable chamber to simulate the extreme temperature environment, the AMC7150 EVM board can work well, as the measured waveforms of LED current and the oscillating waveform of CT shown in the following table: Table AMC7150 EVM can work well under ambient temperature from -40℃ to +125℃. Ambient Temperature Measured waveforms Test condition CH1：iL CH2：CT Vcc=12V Rsen=0.5Ω Room Temperature L=180uH LED=1pcs CT=820pF Vf,LED=3.34V CH1：iL CH2：CT Vcc=12V Low Rsen=0.5Ω Temperature L=180uH -40℃ LED=1pcs CT=820pF Vf,LED=3.626V CH1：iL CH2：CT Vcc=12V High Rsen=0.5Ω Temperature L=180uH +125℃ LED=1pcs CT=820pF Vf,LED =3.2V Copyright © 2006, ADDtek Corp. 6-1 DA011 － September 1, 2006 www.micro-bridge.com AMC7150 7. Relationship between VIN and the LED Driving Current When VIN changes, the RMS value of LED driving current will change slightly. Vin vs I(LED,RMS) LED Driving Current (mA) 420 400 380 360 340 320 300 6 8 10 12 14 16 18 20 Vin (V) di 381 mA − 357 mA = 6 mA = V dv 12 V − 8V VIN=8~12V % V = 6 mA V = 1.57 % V 381mA 396 mA − 381 mA di = = 3 . 75 mA V 16 V − 12 V dv VIN=12~16V % Copyright © 2006, ADDtek Corp. V = 3 . 75 mA 381 mA 7-1 V = 0 . 98 % V DA011 － September 1, 2006 www.micro-bridge.com