ADP1650

1.5 A LED Flash Driver with I2C-Compatible Interface ADP1650 FEATURES Ultracompact solution Small, 2 mm × 1.5 mm, 12-ball WLCSP package Smallest footprint, 1 mm height, 1 μH power inductor LED current source for local LED grounding Simplified routing to/from LED Improved LED thermals Synchronous 3 MHz PWM boost converter, no external diode High efficiency: 90% peak Reduces high levels of input battery current during flash Limits battery current drain in torch mode I2C programmable Currents up to 1500 mA in flash mode for one LED with 7% accuracy over all conditions Currents up to 200 mA in torch mode Programmable dc battery current limit (4 settings) Programmable flash timer up to 1600 ms Low VBAT mode to reduce LED current automatically 4-bit ADC for LED VF, die/LED temperature readback Control I2C-compatible control registers External STROBE and torch input pins 2 transmitter mask (TxMASK) inputs Safety Thermal overload protection Inductor fault detection LED short-/open-circuit protection FUNCTIONAL BLOCK DIAGRAM INPUT VOLTAGE = 2.7V TO 5.0V 10µF 1.0µH TX1/TORCH TX2/ILED/ADC GPIO1 GPIO2 VIN SW VOUT 10µF ADP1650 STROBE SCL SDA EN SGND PGND 08837-001 LED_OUT MAX 1.5A Figure 1. C1 Li-ION + L1 PGND Li-ION + C2 INDUCTOR DIGITAL INPUT/ OUTPUT APPLICATIONS Camera-enabled cellular phones and smart phones Digital still cameras, camcorders, and PDAs AREA = 16.4mm 2 08837-002 LED ANODE Figure 2. PCB Layout GENERAL DESCRIPTION The ADP1650 is a very compact, highly efficient, single white LED flash driver for high resolution camera phones that improves picture and video quality in low light environments. The device integrates a programmable 1.5 MHz or 3.0 MHz synchronous inductive boost converter, an I2C-compatible interface, and a 1500 mA current source. The high switching frequency enables the use of a tiny, 1 mm high, low cost, 1 µH power inductor, and the current source permits LED cathode grounding for thermally enhanced, low EMI, and compact layouts. The LED driver maximizes efficiency over the entire battery voltage range to maximize the input-power-to-LED-power conversion and minimize battery current draw during flash events. A programmable dc battery current limit safely maximizes LED current for all LED VF and battery voltage conditions. Two independent TxMASK inputs permit the flash LED current and battery current to reduce quickly during a power amplifier current burst. The I2C-compatible interface enables the programmability of timers, currents, and status bit readback for operation monitoring and safety control. The ADP1650 comes in a compact 12-ball, 0.5 mm pitch package and operates within specification over the full −40°C to +125°C junction temperature range. For more information about the ADP1650, contact Analog Devices, Inc., Sales Office, at http://www.analog.com/sales. Rev. A 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 rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. www.analog.com Tel: 781.329.4700 Fax: 781.461.3113 ©2010 Analog Devices, Inc. All rights reserved. ADP1650 OUTLINE DIMENSIONS 1.54 1.50 1.46 0.660 0.602 0.544 0.022 REF SEATING PLANE 3 2 1 A BALL A1 IDENTIFIER 2.04 2.00 1.96 0.330 0.310 0.290 1.50 REF B C D TOP VIEW (BALL SIDE DOWN) 0.380 0.352 0.324 0.04 MAX COPLANARITY 0.280 0.250 0.220 0.50 REF 1.00 REF BOTTOM VIEW (BALL SIDE UP) Figure 36. 12-Ball Wafer Level Chip Scale Package [WLCSP] (CB-12-4) Dimensions shown in millimeters REVISION HISTORY 6/10—Rev. 0 to Rev. A Changes to Contact Information .................................................... 1 5/10—Revision 0: Initial Version I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors). ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08837-0-6/10(A) Rev. A | Page 2 of 2 020409-B