DATA SHEET AAT2848 High Current Charge Pump For Backlight Display and Flash Applications General Description Features The AAT2848 is a tri-mode charge pump optimized for Tri-Mode (1x/1.5x/2x) Charge Pump systems operating with lithium-ion/polymer batteries. The Four 30mA Backlight LED Channels 2 charge pump provides power for both white LED backlight Independent S Cwire Control for Backlight and flash, with an integrated four channel backlight LED 32-Level Programmable Backlight Current Control current sink plus two channel flash LED current sinks. Linear, Inverting Two 300mA Flash LED Channels Each backlight channel can drive up to 30mA, while each 2 Independent S Cwire Control for Flash flash current sink/channel can drive up to 300mA (600mA 16-Level Programmable Flash Current Control 2 total). Two independent S Cwire (Skyworks Simple Linear, Inverting Serial Control) serial digital interface inputs enable, User-Programmable Full Scale Current for Backlight disable, and set LED current to one of 32 levels for the and Flash backlight and to one of 16 levels for the flash, with full- User-Programmable Fade-In/Fade-Out Function for scale current independently set for backlight and flash Backlight using external resistors. User-Programmable Safety Timer for Flash LED The AAT2848 offers a built-in fade-in/out function for Protection linear control of the backlight current during ON/OFF Built-In Thermal Protection transitions. The fade time is programmable by an exter- Automatic Soft-Start nal capacitor. -40C to +85C Temperature Range Available in TQFN33-20 Package The AAT2848 also offers a built-in flash timeout function as a safety feature associated with the high power flash driver. The safety timer is also programmable via an Applications external capacitor. Camera Enabled Mobile Devices The AAT2848 is equipped with built-in short-circuit and Digital Still Cameras over-temperature protection. The soft-start circuitry pre- Multimedia Mobile Phones vents excessive inrush current at start-up and mode transitions. The AAT2848 is available in a Pb-free, space saving TQFN33-20 package and operates over the -40C to +85C ambient temperature range. Typical Application C1 C2 1F 1F WLEDs OSRAM LW M673 C1- C1+ C2- C2+ or equivalent IN OUT Flash LEDs Lumileds PWF1 C V OUT BAT C IN or equivalent 2.2F 4.7F AAT2848 BL1 2 BL2 S Cwire BENS BL3 Backlight Control 2 BL4 S Cwire FENS Flash Control FL1 BSET FL2 FSET RBSET RFSET 15k 14.3k FLTMR FADE C FLTMR C FADE 330nF AGND PGND 47nF Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 202069A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. June 15, 2012 16 10 PGND BL1 17 9 C2- BSET 18 8 C1- FSET IN 19 7 FENS 20 6 C1+ BENS DATA SHEET AAT2848 High Current Charge Pump For Backlight Display and Flash Applications Pin Descriptions Pin Symbol Description Charge pump output supplies current to the backlight and ash LEDs. Connect the backlight and ash LED an- 1 OUT odes to OUT. Bypass OUT to PGND with a 2.2F or larger ceramic capacitor as close to the AAT2848 as possible. 2 C2+ Positive terminal of charge pump capacitor 2. Connect a 1F charge pump capacitor 1 from C2+ to C2-. 3 AGND Analog ground. Connect AGND to PGND at a single point as close to the AAT2848 as possible. Fade-In/Fade-Out timing control capacitor input. Connect a capacitor from FADE to AGND to set the auto- 4 FADE matic backlight current fade-in/fade-out response time. A 47nF capacitor sets the fade-in/fade-out backlight response time to 2.7 seconds. Connect to the IN pin to disable fade functionality. Flash timer control capacitor input. Connect a capacitor from FLTMR to AGND to set the ash timer. A 330nF 5 FLTMR capacitor sets the ash timer to 1.3 seconds. Connect to the AGND pin to disable timer functionality. 2 Backlight enable and serial control input. BENS is the on/off control for the backlight and the S Cwire input to 6 BENS serially control the backlight LED brightness relative to the maximum current set by the resistor at BSET. 2 Flash enable and serial control input. FENS is the on/off control for the ash and the S Cwire input to serially 7 FENS control the ash LED brightness relative to the maximum current set by the resistor at FSET. Flash current setting input. A 9.53k resistor from FSET to AGND sets the maximum ash LED current to 8 FSET 300mA per ash output. Backlight current setting input. A 10k resistor from BSET to AGND sets the maximum backlight LED current 9 BSET to 30mA per backlight output. Backlight LED 1 current sink/channel. BL1 controls the current through backlight LED 1. Connect the cathode 10 BL1 of backlight LED 1 to BL1. If not used, connect BL1 to OUT. Backlight LED 2 current sink/channel. BL2 controls the current through backlight LED 2. Connect the cathode 11 BL2 of backlight LED 2 to BL2. If not used, connect BL2 to OUT. Backlight LED 3 current sink/channel. BL3 controls the current through backlight LED 3. Connect the cathode 12 BL3 of backlight LED 3 to BL3. If not used, connect BL3 to OUT. Backlight LED 4 current sink/channel. BL4 controls the current through backlight LED 4. Connect the cathode 13 BL4 of backlight LED 4 to BL4. If not used, connect BL4 to OUT. Flash LED 1 current sink/channel. FL1 controls the current through ash LED 1. Connect the cathode of ash 14 FL1 LED 1 to FL1. If not used, connect FL1 to OUT. Flash LED 2 current sink/channel. FL2 controls the current through ash LED 2. Connect the cathode of ash 15 FL2 LED 2 to FL2. If not used, connect FL2 to OUT. 16 PGND Power ground. Connect PGND to AGND at a single point as close to the AAT2848 as possible. 17 C2- Negative terminal of charge pump capacitor 2. 18 C1- Negative terminal of charge pump capacitor 1. Power input. Connect IN to the input source voltage. Bypass IN to PGND with a 4.7F or larger ceramic 19 IN capacitor as close to the AAT2848 as possible. 20 C1+ Positive terminal of charge pump capacitor 1. Connect a 1F charge pump capacitor 1 from C1+ to C1-. EP Exposed paddle (bottom). Connect to ground as close as possible to the device. Pin Configuration 1 15 OUT FL2 2 14 C2+ FL1 3 13 EP AGND BL4 4 12 FADE BL3 5 11 FLTMR BL2 Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 202069A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. June 15, 2012