1.5 A LED Flash Driver with 2 I C-Compatible Interface ADP1650 FEATURES FUNCTIONAL BLOCK DIAGRAM INPUT VOLTAGE = 2.7V TO 5.0V Ultracompact solution Small, 2 mm 1.5 mm, 12-ball WLCSP package 10F 1.0H Thin, 3 mm 3 mm 0.75 mm, 10-lead LFCSP package Smallest footprint, 1 mm height, 1 H power inductor LED current source for local LED grounding SW VIN TX1/TORCH GPIO1 Simplified routing to/from LED VOUT TX2/ILED/ADC GPIO2 10F Improved LED thermals Synchronous 3 MHz PWM boost converter, no external diode ADP1650 High efficiency: 90% peak STROBE LED OUT Reduces high levels of input battery current during flash MAX 1.5A SCL Limits battery current drain in torch mode SDA 2 I C programmable EN SGND PGND Currents up to 1500 mA in flash mode for 1 LED with 7% accuracy over all conditions Figure 1. Currents up to 200 mA in torch mode Programmable dc battery current limit (4 settings) Programmable flash timer up to 1600 ms Li-ION + Low VBAT mode to reduce LED current automatically 4-bit ADC for LED V , die/LED temperature readback F L1 PGND Control 2 I C-compatible control registers Li-ION + External STROBE and torch input pins C2 2 transmitter mask (TxMASK) inputs INDUCTOR Safety DIGITAL INPUT/ Thermal overload protection OUTPUT Inductor fault detection LED short-/open-circuit protection 2 AREA = 16.4mm LED ANODE APPLICATIONS Camera-enabled cellular phones and smart phones Figure 2. PCB Layout (WLCSP) Digital still cameras, camcorders, and PDAs GENERAL DESCRIPTION The ADP1650 is a very compact, highly efficient, single white events. A programmable dc battery current limit safely maximizes LED flash driver for high resolution camera phones that LED current for all LED VF and battery voltage conditions. improves picture and video quality in low light environments. Two independent TxMASK inputs permit the flash LED current The device integrates a programmable 1.5 MHz or 3 MHz and battery current to reduce quickly during a power amplifier 2 synchronous inductive boost converter, an I C-compatible 2 current burst. The I C-compatible interface enables the pro- interface, and a 1500 mA current source. The high switching grammability of timers, currents, and status bit readback for frequency enables the use of a tiny, 1 mm high, low cost, 1 H operation monitoring and safety control. power inductor, and the current source permits LED cathode The ADP1650 is available in a compact 12-ball, 0.5 mm pitch grounding for thermally enhanced, low EMI, and compact WLCSP package and a 10-lead LFCSP package, and operates layouts. within specification over the full 40C to +125C junction The LED driver maximizes efficiency over the entire battery temperature range. voltage range to maximize the input-power-to-LED-power conversion and to minimize battery current draw during flash Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20102011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C1 08837-002 08837-001ADP1650 TABLE OF CONTENTS Features .............................................................................................. 1 Indicator LED Driver................................................................. 14 Applications....................................................................................... 1 Low Battery LED Current Foldback ........................................ 14 Functional Block Diagram .............................................................. 1 Programmable Battery DC Current Limit.............................. 15 General Description ......................................................................... 1 Analog-to-Digital Converter Operation ................................. 15 Revision History ............................................................................... 2 5 V Output Operation ............................................................... 16 Specifications..................................................................................... 3 Safety Features................................................................................. 18 Recommended Specifications: Input and Output Capacitance Short-Circuit Fault ..................................................................... 18 and Inductance ............................................................................. 5 Overvoltage Fault ....................................................................... 18 2 I C-Compatible Interface Timing Specifications ..................... 5 Dynamic Overvoltage Mode (DOVP) .................................... 18 Absolute Maximum Ratings............................................................ 6 Timeout Fault.............................................................................. 18 Thermal Data ................................................................................ 6 Overtemperature Fault .............................................................. 18 Thermal Resistance ...................................................................... 6 Indicator LED Fault ................................................................... 18 ESD Caution.................................................................................. 6 Current Limit.............................................................................. 18 Pin Configurations and Function Descriptions ........................... 7 Input Undervoltage .................................................................... 18 Typical Performance Characteristics ............................................. 8 Soft Start ...................................................................................... 18 Theory of Operation ...................................................................... 12 Reset Using the Enable (EN) Pin ............................................. 18 White LED Driver ...................................................................... 12 Clearing Faults............................................................................ 18 Modes of Operation ................................................................... 12 2 I C Interface ................................................................................ 19 Assist Light .................................................................................. 13 2 I C Register Map............................................................................. 20 Flash Mode .................................................................................. 13 Applications Information .............................................................. 26 Assist-to-Flash Operation ......................................................... 13 External Component Selection ................................................ 26 Torch Mode ................................................................................. 13 PCB Layout...................................................................................... 28 Torch-to-Flash Mode ................................................................. 14 Outline Dimensions....................................................................... 29 TxMASK Operation................................................................... 14 Ordering Guide .......................................................................... 29 Frequency Foldback ................................................................... 14 REVISION HISTORY 4/11Rev. B to Rev. C Changed GND to Power Ground Throughout .............................6 Added 10-Lead LFCSP Package........................................Universal Changed IL to IL, ILED to ILED, LED OUT to LED OUT, and Changes to Features Section, General Description Section, and IBAT to IBAT Throughout ..................................................................8 Figure 2 Caption ............................................................................... 1 Change to Figure 10 Caption ...........................................................8 Changes to Table 1............................................................................ 3 Change to Figure 11 Caption ...........................................................9 Changes to Table 5............................................................................ 6 Changed LED MOD = 10 to LED MOD = 11 in Figure 32 ... 14 Added Figure 5 Renumbered Sequentially .................................. 7 Changes to Analog-to-Digital Converter Operation Section and Changes to Table 6............................................................................ 7 Figure 37 .......................................................................................... 15 Changes to PCB Layout Section and Figure 45 Caption........... 28 Changes to Selecting the Output Capacitor Section.................. 26 Added Figure 46.............................................................................. 28 Updated Outline Dimensions ....................................................... 29 6/10Rev. 0 to Rev. A Changes to Ordering Guide .......................................................... 29 Changes to Contact Information.....................................................1 2/11Rev. A to Rev. B 5/10Revision 0: Initial Version Changes to Features Section and General Description Section . 1 Changes to Switching Regulator, Voltage Output Mode, VOUT Voltage Parameter and Digital Inputs/GPIO, Torch Glitch Filtering Delay Parameter, Table 1.................................................. 3 Rev. C Page 2 of 32