austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams sales ams.com Please visit our website at www.ams.com Datasheet AS3642 Ultra Small 500mA Inductive White LED Flash Driver 1 General Description 2 Key Features 2 Total flash driver solution only 11mm The AS3642 is an inductive high efficient DCDC step up converter driving a current source. The DCDC step up High efficiency 4MHz fixed frequency DCDC Boost converter operates at a fixed frequency of 4MHz and converter with soft start allows small coils includes soft startup to allow easy integration into noise LED currents sensitive RF systems. The current source operates in Up to 500mA flash current (15.6mA steps) flash/torch/assist (video/autofocus) and indicator mode. Up to 320mA torch current (10mA steps) The AS3642 includes flash timer, overvoltage, overtem- 1.35mA,2.9mA,4.4mA or 6mA indicator light current perature, undervoltage and LED short circuit protection (PWM with 1...4/32 duty cycle) functions. Flash LED(s) cathode connected to ground: The AS3642 is able to detect a broken coil. Together Improved thermal performance (ground = heat sink) with the LED short and open detection the AS3642 can Simplified PCB layout be used to verify the connection to its external compo- nents and allowing in-circuit test. This reduces test time Adjustable Flash Timer and simplifies production test procedures. 30ms to 480ms in 30ms steps 2 Flash, Torch, Assist and Indicator Mode The AS3642 is controlled by an I C interface to allow sophisticated control of all settings like currents and tim- Protection functions: ings. Automatic Flash timer to protect the LED Overvoltage and undervoltage Protection The complete flash driver solution measures only Overtemperature Protection 2 11mm PCB area. LED short circuit protection Available in tiny WL-CSP Packages The AS3642 is available in a space-saving WL-CSP 2x3 balls 0.5mm pitch, 1.5x1.1x0.6mm package size package measuring only 1.5x1.1x0.6mm and operates over the -30C to +85C temperature range. 3 Applications Figure 1. Typical Operating Circuit Flash/Torch for mobile phones, digital cameras and PDA %% & ., %%, /,/ 0 ( ) & * ) )* / 1 AS3642 AS3642 www.austriamicrosystems.com/AS3642 1.2-2 1 - 26 (ptr)500mA ams AG Technical content still valid +, -