AP8801M8G-13

AP8801 DIODES | Alldatasheet

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Technical content

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 1 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated

• LED driving current up to 500mA
• Operating input voltage up to 48V
• High efficiency up to 92%
• High switching frequency up to 500kHz
• PWM/DC input for dimming control
• Built-in output open-circuit protection
• SOP-8L and MSOP-8L are available in “Green” Molding Compound (No Br, Sb)
• Lead Free Finish/RoHS Compliant (Note 1) The AP8801 is a step-down DC/DC converter designed to drive LEDs with a constant current. The device can drive up to thirteen LEDs, depending on the forward voltage of the LEDs, in series from a voltage source of 8V to 48V. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The AP8801 switches at frequency up to 500kHz. This allows the use of small size external components, hence minimizing the PCB area needed. Maximum output current of AP8801 is set via an external resistor connected between the V IN and SET input pins. Dimming is achieved by applying either a DC voltage or a PWM signal at the CTRL input pin. An input voltage of 0.2V or lower at CTRL shuts down the output at SW and puts the device into a low-current standby state.
• Commercial & industrial lighting
• Small LCD panel backlight
• Appliances interior lighting
• Architecture Detail lighting AP 8801 XX G - 13 Package Packing S : SOP-8L Green 13 : Tape & ReelG : Green M8 : MSOP-8L Device Package Code Packaging (Note 2) 13” Tape and Reel Quantity Part Number Suffix AP8801SG-13 S SOP-8L 2500/Tape & Reel -13 AP8801M8G-13 M8 MSOP-8L 2500/Tape & Reel -13 Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at http://www.diodes.com/products/lead_free.html . 2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at http://www.diodes.com/datasheets/ap02001.pdf . Features General Description

Applications

Ordering Information

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 2 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated (1) SOP-8L (2) MSOP-8L ( Top View ) NC SW CTRLSET SWVIN GND GNDAP8801 ( Top View ) NC SW CTRLSET SWVIN GND GNDAP8801 Pin Name Description SW Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to reduce EMI. GND GND pin SET Set Nominal Output Current Pin. Configure the output current of the device. CTRL Dimming and On/Off Control Input. Input voltage of 0.2V or lower forces the device into low current standby mode and shut off the output. A PWM signal allows the output current to be adjusted above or below the level set by the resistor connected to SET input pin. The input impedance is about 50kΩ, and if the pin is left open VCTRL = VREF VIN Input Supply Pin. Must be locally bypassed. NC No connection Pin Assignments Pin Descriptions

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 3 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated Block Diagram Voltage Regulator 5V R CTRL VIN GND SET SW Comparator Sensing Block VREF 1.25V AP8801 PWM/DC Control Figure 1: AP8801 block diagram Absolute Maximum Ratings Symbol Parameter Rating Unit VIN VIN pin voltage -0.3~50 V VSW SW voltage -0.3~50 V TJ Junction Temperature 150 oC TLEAD Lead Temperature Soldering 300 oC TST Storage Temperature Range -65 to +150 oC Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values m ust therefore not be exceeded under any condition. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices Recommended Operating Conditions Symbol Parameter Min Max Unit TA Ambient Temperature Range -40 105 ºC

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 4 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated Electrical Characteristics (VIN =24V, TA=25oC, unless otherwise specified) Symbol Parameter Conditions Min. Typ. Max. Unit VIN Operating Input Voltage 8.0 - 48 V IOUT Continuous switch current (Note 3) 500 mA IQ Quiescent Current - 78 120 μA FOSC Switching Frequency - - 0.5 MHz VTHD Internal Threshold Voltage 184 200 216 mV VREF Internal Reference Voltage - 1.25 - V SET SET pin input current VSET=VIN-0.2 - 7 - μA Rds(on) On Resistance of MOSFET I SW=0.4A 0.7 1.15 Ω ISW Leaka ge Switch leakage current - - 8 μA EN Voltage High ON 1.25 - - V EN Voltage Low OFF - - 0.2 V θJA Thermal Resistance Junction-to-Ambient SOP-8L (Note 4) - 88 - °C/W MSOP-8L (Note 4) - 128 - °C/W θJC Thermal Resistance Junction-to-Case SOP-8L (Note 4) - 58 - °C/W MSOP-8L (Note 4) - 90 - °C/W Notes: 3. Refer to figure 6 for the device derating curve. 4. Test condition for SOP-8L and MSOP-8L: Device mounted on FR-4 PCB, 2”x2”, 2oz copper, minimum recommended pad layout on top layer and thermal vias to bottom layer ground plane. For better thermal performance, larger copper pad for heat-sink is ne eded. Typical Application Circuit

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 5 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated LED Current Control The LED current is controlled by the resistor RSET in Figure 2. Connected between V IN and SET the nominal average output current in the LED(s) is defined as: SET THD LED R VI = If the CTRL pin is driven by an external voltage (lower than 2.5V), the average LED current is: SET THD REF CTRL LED R V V VI = LED current Versus RSET and VCTRL 0.4 0.47 0.56 0.82 0.47 0.68 0.82 1 1.2 1.5 2 3 1.2 1.5 0.82 0.68 1.5 1.2 100 200 300 400 500 600 RSE T value [Ohms ] LED Current [mA] LED current @ VCTRL = 1.25V LED current @ VCTRL = 2.5V LED current @ VCTRL = 0.625V Figure 3: LED Current setting Vs RSET and VCTRL

Application Information

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 6 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated Inductor Selection This section highlights how to select the inductor suitable for the application requirements, in terms of switching frequency, LED current accuracy and temperature. Switching Frequency @ ILED = 500mA 100 470 100 100 150 470 150 220 470 150 220 220 100 200 300 400 500 600 0 50 100 150 200 250 300 350 400 450 500 Inductor Value [uH] Frequency [kHz] 12V - 1 LED 24V - 3 LEDs 48V - 6 LEDs Figure 4: Switching Frequency Vs Inductor Value Application Information (Continued)

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 7 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated The inductor influences the LED current accuracy that the system is able to provide. The following section highlights how to select the inductor in relation to the device packages and the LED current, while maintaining the chip temperature below 70˚C. AP8801 Minimum Recommended Inductor - LED Current 500mA 8% Accuracy, <70°C Case Temperature 12Number of LEDs Supply Voltage (V) Legend 47µH 68µH 100µH 150µH 220µH 470µH 47uH 68uH 100uH 150uH 220uH 470uH Figure 5: Minimum recommended inductor with 500mA LED current Capacitor Selection The small size of ceramic capacitors makes them ideal for AP8801 applications. X5R and X7R types are recommended because they retain their capacitance over wider voltage and temperature ranges than other types such as Z5U. A 2.2μF input capacitor is sufficient for most intended applications of AP8801. A 4.7μF input capacitor is suggested for application with an input voltage equal or higher than 40V. Diode Selection Schottky diodes, e.g. B1100, with their low forward voltage drop and fast reverse recovery, are the ideal choice for AP8801 applications. PWM Dimming A Pulse Width Modulated (PWM) signal with a max resolution of 8bit, can be applied to the CTRL pin to change the output current to a value above or below the nominal average value set by resistor RSET. To achieve this resolution the PWM frequency has to be lower than 500Hz. Application Information (Continued)

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 9 of 11 M A R C H 2 0 0 9 www.diodes.com © Diodes Incorporated Marking Information (1) SOP-8L ( Top View ) AP8801 YY WW X X Logo Part Number WW : Week : 01~52; 52 YY : Year : 08, 09,10~ G : Green X : Internal Code represents 52 and 53 week (2) MSOP-8L AP8801 ( Top View ) Y W X Part Number Logo Y : Year : 0~9 A~Z : Green 87 65 1 234 a~z : 27~52 week; z represents W : Week : A~Z : 1~26 week; 52 and 53 week

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 10 of 11 MARCH 2009 www.diodes.com © Diodes Incorporated Package Information (All Dimensions in mm) (1) Package Type: SOP-8L 1.27typ 0.3/0.5 7°~9° 4.85/4.95 3.85/3.95 5.90/6.10 0.15/0.25 7°~9° 0.62/0.82 0.10/0.20 Gauge Plane 0.254 Seating Plane 0.35max. 45° Detail "A" Detail "A" 1.30/1.50 1.75max. Land Pattern Recommendation (Unit: mm) 6x-1.27 8x-1.55 8x-0.60 5.4 0°/8° (2) Package Type: MSOP-8L 2.9/3.1 4.7/5.1 0.65Bsc. 0.22/0.38 0.05 0.15Typ. 0.4/0.8 0.25 0.95Ref. Gauge plane 0°/8° "A" DETAIL "A" 6x-0.65 Land Pattern Recommendation (Unit:mm) 8x-1.4 4.4 8x-0.45 0.05/0.15

500mA LED Step-Down Converter A P 8 8 0 1 R e v . 1 11 of 11 MARCH 2009 www.diodes.com © Diodes Incorporated IMPORTANT NOTICE LIFE SUPPORT Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to any product herein. Diodes Incorporated does not assume any liability arising out of the application or use of any product described herein; neither does it convey any license under its patent rights, nor the rights of others. The user of products in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on our website, harmless against all damages. Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the President of Diodes Incorporated.