DC/DC Controller for High Current LED Camera Flash BCT 3521Q BlueChips Technology A Premier Design Solutions Company….. DC/DC Controller for High Current LED Camera Flash BCT 3521Q Jan2005

The Features: BCT 3521Q Applications: Camera flash in mobile phone, PDAs Camera flash in low end digital camera Emergency light, Flash Light On chip DC/DC converter with current mode control Maximum continuous DC current: 350mA Maximum pulsed output current: 450mA (Duration < 200mS) Integrated thermal protection circuit O/P current adjustable by external resistor at pin CS On Chip Oscillator Low power consumption Wide operation temperature: -200C to 700C Available in QFN16L package (3mm x 3mm) Jan2005

System Advantages: High Output dc current: 350mA High Output pulsed current: 450mA Charge Pump vs. PWM controller One single configuration vs. complicate boost-buck PWM controller. Advanced Switching Capacitor Technologies  No external MOSFET/ BJT, Coil-less, no schottky diode, low EMI, in-expensive external components. Multi source of LEDs  Current regulator (irrelevant to the LED forward voltage) High efficiency and lower power consumption Extend the battery life Jan2005

Camera Phone with LED Flash Sanyo SCP5300 Motorola V690 Siemens SL65 Sony Ericsson SC003 Jan2005

The performance Without Flash With Flash Jan2005

BCT3521Q Application One Current Setting 3.6V Re-chargeable Lithium-ion Battery 1~10mF 10mF 5, 6 8, 9 10mF 10mF 12 VIN C2P C2N VOUT 2 MCU BCT3521Q CS I/O SHDNB LED Flash GND C1P C1N FLASH 1~10mF LED ON LED OFF 0.01 ~ 0.2Sec 1 ~ 3 Sec Jan2005

BCT3521Q Application Two Current Settings 3.6V Re-chargeable Lithium-ion Battery 1~10mF 10mF 5, 6 8, 9 10mF 10mF 12 VIN C2P C2N VOUT 2 MCU BCT3521Q CS M1 SHDNB I/O ON /OFF Current 1 Current 2 LED Flash GND C1P C1N FLASH M2 1~10mF LED ON LED OFF 0.01 ~ 0.2Sec 1 ~ 3 Sec M2 ON M1 OFF Jan2005

BCT 3511S Status E/S: Available NOW Demo board: Available NOW Production: Now Jan2005

LED vs Xenon Flash LED Flash Xenon Flash Minimal External Components I. 2x 0805 1uF ceramic cap ~US0.01 II. Output Filter capacitor I. External MOSFET / BJT ? ~US0.12 Volume 1.3mm3 Recycle Time No 3 ~ 4 sec Resvior capacitor No need 10uF 10V filter capacitor 0.5 ~ 1.5 mm3 8uF ~ 35uF 330V Angle of light coverage 20 ~ 25 deg Thermal Protection Yes (@110 deg C) May have EMI Interference Good, can be used in RF application Noise Efficiency 60 ~85 % 75 ~ 85% Package SOP14 SOP8 System Cost $$$ $$$$ Jan2005

Flash light Control One shot Flash Correct exposure value at 2 ~ 6 points Pre-flash Continuous Mode Jan2005

Thank You ! Questions & Answer Jan2005