PAM2808EV1 User Guide 5W HIGH POWER HBLED DRIVER General Description The PAM2808 is a 5W high power HBLED Driver. The PAM2808 supports a range of input voltages from 2.5V to 6.0V. It features high efficiency (~90%) and low quiescent current, making it ideal for battery powered applications. This evaluation board contains a high current 1.5A WLED onboard for quick turn on demonstration. If users required to use any specific types of LEDs, just desolder the LED onboard and connect their required LEDs (Anode to the Vout pin, and Cathode to the FB pin). A bill of materials, schematics, and layout are included that describes the parts used on this demonstration board along with measured performance characteristics. These materials can be used as a reference design. Key Features High Output Current Up to 1.5A Low Feedback Voltage 0.1V Stable with a Ceramic Output Capacitor Low Quiescent Current Open Load °C Protection Over Temperature Shutdown Low Temperature Coefficient PAM2808EV1 Specifications Parameter Value Input Voltage LED Current Number of LEDs XYZ Dimension 2.8 to 5.5VDC 330mA (Adjustable) 1 2” x 1.5” x 0.7” Evaluation Board Figure 1: Top View Applications High Bright LED Driver White LED Torch (Flashlight) PAM2808EV1 Rev1 February 2015 www.diodes.com Figure 2: Bottom View Connection Instructions Input Voltage: 2.8 to 6.0VDC (VIN, GND) Onboard high current 1.5A LED Page 1 of 5 PAM2808EV1 User Guide 5W HIGH POWER HBLED DRIVER Evaluation Board Schematic Figure 3: Evaluation Board Schematic Evaluation Board Layout Figure 4: PCB Layout Top View Figure 5: PCB Layout Bottom View Quick Start Guide 1. 2. 3. 4. By default, the evaluation board is preset at 300mA LED Current by RS1 (0.3 Ohm). Ensure that the DC source is switched OFF or disconnected. Connect the 2.8 to 6.0VDC DC line wires of power supply to VIN and GND on the board. Turn on the main switch. LED should light up underneath the board. PAM2808EV1 Rev1 February 2015 www.diodes.com Page 2 of 5 PAM2808EV1 User Guide 5W HIGH POWER HBLED DRIVER Bill of Material # 1 Quantity 1 Part number PAM2808BLBR Manufacturer Diodes Inc Description LED Driver SOP‐8(EP) 2 3 4 5 Name IC1 Cin, Cout CEN RS1 REN 2 1 1 1 Taiyo Yuden Taiyo Yuden Yageo Yageo CREE 4.7µF Cer Cap 10V 10% X5R 0805 1µF Cer Cap 10V 10% X5R 0805 6 LED1 1 LMK212BJ475KD‐T LMK212SD104JG‐T RL1218FK‐070R3L RMCF0805FT10R0CT‐ND XPGWHT‐L1‐0000‐ 00BE8CT‐ND 0.3Ω Resistor 1W 1% 1218 SMD 10Ω Resistor 1/8W 1% 0805 SMD White color, Vf=2.9V, and max current 1.5A Functional Performance (1 LED @330mA) Vin (DC) 2.8 3 3.5 4 4.5 5 5.5 6 Pin (W) 0.325 0.789 0.921 1.052 1.184 1.310 1.441 1.560 V_out (V) 2.70 2.79 2.77 2.77 2.77 2.77 2.76 2.76 I_out (mA) 110 260 260 260 260 260 260 250 I_out(mA) vs Input Voltage Efficiency (%) 91.44 91.87 78.24 68.41 60.79 54.88 49.83 44.23 # of LEDs 1(onboard) Efficiency(%) vs Input Voltage PAM2808EV1 Vin=2.8‐6.0VDC; OUT=1 LED PAM2808EV1 Vin=2.8‐6.0VDC; OUT=1 LED 300 100 260 80 Efficiency (%) I_out(mA) P_out (W) 0.297 0.725 0.720 0.720 0.719 0.719 0.718 0.690 220 180 140 60 40 20 0 100 2 3 4 5 6 Input Voltage (VDC) Figure 6 Vin (DC) vs. Iout (mA) PAM2808EV1 Rev1 February 2015 www.diodes.com 7 2 3 4 5 6 Input Voltage (VDC) Figure 7 Vin (DC) vs. Efficiency (%) Page 3 of 5 7 PAM2808EV1 User Guide 5W HIGH POWER HBLED DRIVER Application Information Setting the Output Current: The internal feedback (FB) voltage is 0.1V (Typical). The output current is calculated as below: ILED = 0.1/RS1 The output Current is given by the following table. RS1(Ω) ILED (mA) 0.3 0.14 0.1 0.067 330 700 1000 1500 Thermal Shutdown When the die temperature exceeds +150°C, a reset occurs and the reset remains until the temperature decrease to +110°C, at which time the circuit can be restarted. PAM2808EV1 Rev1 February 2015 www.diodes.com Page 4 of 5 PAM2808EV1 User Guide 5W HIGH POWER HBLED DRIVER IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. 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