AAT2866IMK-3-T1

DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit General Description Features The AAT2866 is a highly integrated charge pump-based lighting management unit (LMU) offering eight LED channels with three linear regulators optimized for single-cell lithium-ion/polymer systems. The charge pump provides power for all LED outputs and multiple backlight and flash LED configurations are available. The backlight LED channel outputs are programmable up to 31mA and the total flash LED output current can be programmed up to 600mA. • Input Voltage Range: 2.7V to 5.5V • AS2Cwire Serial Interface • Tri-Mode Charge Pump ▪ Drives up to Eight LEDs • Programmable Backlight Current by: ▪ AS2Cwire Interface • 31mA Maximum Current per Channel • 32 Linear Current Settings • Independent Main/Sub Settings ▪ PWM Control • All Channels BL1-BL6 (default) • Main Backlight BL1-BL4 (optional) • All Channels BL1-BL7 (AAT2866-3) • 60Hz to 100kHz ▪ Programmable Flash Current • 600mA Total Flash Current • 16 Linear Current Settings • 2 Channel Configuration • 1MHz Switching Frequency • Automatic Soft Start • Three Linear Regulators ▪ 300mA Output Current ▪ 150mV Dropout ▪ Programmable Control from 1.2V to 3.3V ▪ Output Auto-Discharge for Fast Shutdown • Built-In Thermal Protection • Automatic Soft Start • -40°C to +85°C Temperature Range • TQFN34-24 Package Skyworks' AS2Cwire™ single-wire interface is used to enable, disable, and set the current to one of 32 levels for the backlight and one of 16 levels for the flash. A separate flash enable and programmable safety timer are included for easy flash control. Backlight current matching is better than 3% for uniform display brightness, and flash current matching is better than 5% for uniform power dissipation. As an alternative, the main backlight LED's output current can be controlled via pulse width modulation (PWM). The AAT2866 also offers three high-performance lownoise MicroPower™ low dropout (LDO) linear regulators. The regulators output voltages are set through the AS2Cwire serial interface. Each LDO can supply up to 300mA load current and ground-pin current is only 80µA making the AAT2866 ideal for battery-operated applications. The AAT2866 is available in a Pb-free, space-saving TQFN34-24 package and operates over the -40°C to +85°C ambient temperature range. Applications • Camera Enabled Mobile Devices • Digital Still Cameras • Multimedia Mobile Phones Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 1 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Typical Application CF1 1µF C1+ CF2 1µF C1- C2+ IN VBAT 3.6V CIN 2.2µF PWMM C2OUT VOUT COUT 2.2µF AAT2866 IN PWMM BL1 BL2 BL3 BL4 EN/SET EN/SET BL5 BL6 BL7/FL2 FL_EN FL_EN FL1 LDOA EN_LDOA/B/C EN_LDOA/B/C LDOB 2 COUTA 2.2µF VLDOB at 300mA COUTB 2.2µF LDOC AGND VLDOA at 300mA PGND VLDOC at 300mA COUTC 2.2µF Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Pin Descriptions Pin # Symbol Function 1 OUT O 2 C2+ I 3 EN/SET I 4 FL_EN I 5 PWMM I 6 EN_LDOA/B/C I 7 AGND GND 8 LDOC O 9 IN I 10 LDOB O 11 LDOA O 12 BL1 O 13 BL2 O 14 BL3 O 15 BL4 O 16 BL5 O 17 BL6 O 18 BL7/FL2 O 19 FL1 O 20 21 22 PGND C2C1- GND I I 23 IN I 24 C1+ I EP GND Description Charge-pump output. OUT is the output of the charge pump and supplies current to the backlight and flash LEDs. Connect the backlight and flash LED anodes to OUT. Bypass OUT to PGND with a 2.2μF or larger ceramic capacitor as close to the AAT2866 as possible. Positive terminal of charge pump capacitor 2. Connect the 1μF charge pump capacitor 2 from C2+ to C2-. AS2Cwire serial input. EN/SET is the address and data input of the AS2Cwire serial interface. AS2Cwire is used to control backlight, flash and LDO functions. Flash enable. FL_EN is the enable control for the Flash LEDs. For the FL_EN pin to enable the flash current the EN/SET pin must also be pulled high. PWM input pin. Apply a PWM signal of varying duty cycle to modulate the LED current on BL1, BL2, BL3, BL4, BL5 & BL6 (Default). PWM frequency can vary up to 100kHz. The LED current maximum will be set at the default setting if no programming is applied. If not used, connect PWMM to IN. LDOA, LDOB and LDOC enable pin. EN_LDOA/B/C enables all LDO regulators A. The EN/SET pin must also be pulled high for the LDO regulators to be enabled. The EN_LDOA/B/C input can be overwritten via the AS2Cwire interface to disable either LDOA or LDOB or LDOC. Analog ground. Connect AGND to PGND at a single point as close to the AAT2866 as possible. LDOC is the voltage output of LDOC. Bypass LDOC to AGND with a 2.2μF or greater capacitor as close to the AAT2866 as possible. Input power pin for all three LDOs. Connect Pin 11 to Pin 23 with as short a PCB trace as practical. LDOB is the voltage output of LDOB. Bypass LDOB to AGND with a 2.2μF or greater capacitor as close to the AAT2866 as possible. LDOA is the voltage output of LDOA. Bypass LDOA to AGND with a 2.2μF or larger ceramic capacitor as close to the AAT2866 as possible. Backlight LED 1 current sink. BL1 controls the current through backlight LED 1. Connect the cathode of backlight LED 1 to BL1. If not used, connect BL1 to OUT. Backlight LED 2 current sink. BL2 controls the current through backlight LED 2. Connect the cathode of backlight LED 2 to BL2. If not used, connect BL2 to OUT. Backlight LED 3 current sink. BL3 controls the current through backlight LED 3. Connect the cathode of backlight LED 3 to BL3. If not used, connect BL3 to OUT. Backlight LED 4 current sink. BL4 controls the current through backlight LED 4. Connect the cathode of backlight LED 4 to BL4. If not used, connect BL4 to OUT. Backlight LED 5 current sink. BL5 controls the current through backlight LED 5. Connect the cathode of backlight LED 5 to BL5. If not used, connect BL5 to OUT. Backlight LED 6 current sink. BL6 controls the current through backlight LED 6. Connect the cathode of backlight LED 6 to BL6. If not used, connect BL6 to OUT. AAT2866: Flash LED 2 current sink. FL2 controls the current through Flash LED 2. Connect the cathode of Flash LED 2 to FL2. If not used, connect FL2 to OUT. AAT2866-3: Backlight LED 7 current sink. BL7 controls the current through backlight LED 7. Connect the cathode of backlight LED 7 to BL7. If not used, connect BL7 to OUT. Flash LED 1 current sink. FL1 controls the current through Flash LED 1. Connect the cathode of Flash LED 1 to FL1. If not used, connect FL1 to OUT. Power ground. Connect PGND to AGND at a single point as close to the AAT2866 as possible. Negative terminal of charge pump capacitor 2. Negative terminal of charge pump capacitor 1. Power input. Connect IN to the input source voltage. Bypass IN to PGND with a 2.2μF or larger ceramic capacitor as close to the AAT2866 as possible. Positive terminal of charge pump capacitor 1. Connect the 1μF charge pump capacitor 1 from C1+ to C1-. Exposed paddle (bottom) Connect to PGND/AGND as close to the AAT2866 as possible. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 3 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Pin Configuration TQFN34-24 (Top View) PGND C2C1IN C1+ 24 OUT C2+ EN/SET FL_EN PWMM EN_LDOA/B/C AGND 23 22 21 20 1 19 2 18 3 17 4 16 5 15 6 14 7 13 8 9 10 11 FL1 BL7/FL2 BL6 BL5 BL4 BL3 BL2 12 BL1 LDOA LDOB IN LDOC Part Number Description1 Backlight LED Outputs Part Number Main Sub Flash LED Output AAT2866IMK-T1 AAT2866IMK-3-T1 6/4 5 0/2 2 2 1 Absolute Maximum Ratings2 TA = 25°C unless otherwise noted. Symbol Description IN, OUT, BL1, BL2, BL3, BL4, BL5, BL6, FL1, BL7/FL2 Voltage to AGND C1+, C2+ Voltage to AGND C1-, C2-, LDOA, LDOB, LDOC, EN/SET, FL_EN, EN_LDOA/B/C, PWMM Voltage to AGND PGND Voltage to AGND Value Units -0.3 to 6.0 -0.3 to VOUT + 0.3 -0.3 to VIN + 0.3 -0.3 to 0.3 V Thermal Information3, 4 Symbol ΘJA PD TJ TLEAD Description Thermal Resistance Maximum Power Dissipation Operating Junction Temperature Range Maximum Soldering Temperature (at Leads) Value Units 50 2 -40 to 150 300 OC/W W °C 1. Backlight Main and Sub are configured to be equal by default. Main and Sub can be programmed via AS2Cwire to be 4 Main and 2 Sub . For more information, see the Applications Information section of this datasheet. 2. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 3. Derate 20mW/°C above 25°C ambient temperature. 4. Mounted on a FR4 circuit board. 4 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Electrical Characteristics1 VIN = 3.6V; CIN = COUT = 2.2μF; C1 = C2 = 1µF; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Conditions VIN IN Operating Voltage Range IN Operating Current (1x mode, Main Channels enabled, IBLX not included) IN Operating Current (2x mode, IIN Main Channels enabled, IBLX not included) IN Operating Current (LDOA, LDOB and LDOC enabled) IIN(SHDN) IN Shutdown Current Over-Temperature Shutdown TSD Threshold Over-Temperature Shutdown TSD(HYS) Hysteresis Charge Pump Section VOUT OUT Output Voltage IOUT(MAX) OUT Maximum Output Current BL1-BL7 Charge Pump Mode VIN(TH_H, BL) Transition Hysteresis FL1-FL2 Charge Pump Mode VIN(TH_H, FL) Transition Hysteresis fOSC Charge Pump Oscillator Frequency tCP(SS) Charge Pump Soft-Start Time BL1-BL7, FL1, FL2 LED Drivers IBLx BL1-BL7 Current Accuracy IBL_x BL1-BL7 Current Accuracy IBL_(10%) ΔI(BLx)/ IBL(AVG) VBL_(TH) BL1-BL7 PWM Current Accuracy BL1-BL7 Current Matching 2 BL1-BL7 Charge Pump Transition Threshold IFL[1] FL1,FL2 Current Accuracy IFL[1](DATA13) FL1, FL2 Current Accuracy ΔI(FLx)/ IFL(AVG) FL1-FL2 Current Matching VFL[1/2](TH) FL1,FL2 Charge Pump Transition Threshold ΔtFL/tFL_SET Flash Safety Timer Period Min Typ Max Units 5.5 V 600 µA 5.5 mA 225 µA 1.0 µA 2.7 EN/SET = PWMM = BL1-BL7 = IN, FL_EN = EN_LDOA/B/C = AGND; 2x Mode; EN/SET= PWMM = IN, FL_EN = EN_LDOA/B/C = AGND; BL1-BL7 = OPEN; ADDR=12, DATA=15; ADDR=13, DATA=16 EN/SET = PWMM = EN_LDOA/B/C = IN; FL_EN = AGND; ADDR = 0; DATA = 6; No Load EN/SET, FL_EN, EN_LDOA/B/C, PWMM = AGND VIN = 3.0V, VOUT = 4.0V EN/SET = IN; VIN – VF = 1V; ADDR=3, DATA=2; ADDR=2, DATA=12 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=10, DATA=1 TA = 25°C TA = 25°C EN/SET = IN; VIN – VF = 1V; ADDR=3, DATA=3; ADDR=2, DATA=12 EN/SET = IN; VIN – VF = 1V; ADDR=3, DATA=4; ADDR=2, DATA=14 DC=10%; fPWM=10kHz; VIN-VF=1.5V EN/SET = IN; VIN – VF = 1V; ADDR=3, DATA=3; ADDR=2, DATA=12 EN/SET = IN; VIN – VF = 1V; ADDR=3, DATA=3; ADDR=2, DATA=12 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=10, DATA=1 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=10, DATA=13 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=10, DATA=1 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=10, DATA=1 EN/SET = FL_EN = IN; VIN – VF = 1V; ADDR=11, DATA=1 140 °C 15 °C 5.2 800 V mA 0.3 V 1 V 1 100 MHz µs 18 20 22 mA 1.6 2 2.4 mA 2.5 mA 3 % 0.2 V 270 300 330 mA 54 60 66 mA 1.5 5 % 0.45 V 2 2.5 s 1. The AAT2866 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls. 2. Current matching is defined as the deviation of any sink current from the average of all active channels. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 5 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Electrical Characteristics1 VIN = 3.6V; CIN = COUT = 2.2μF; C1 = C2 = 1µF; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Linear Regulators ΔVLDO[A/B/C]/ LDOA, LDOB, LDOC Output Voltage VLDO[A/B/C] Tolerance LDOA, LDOB, LDOC Maximum Load ILDO[A/B/C](MAX) Current VLDO[A/B/C](DO) LDOA, LDOB, LDOC Dropout Voltage2 ∆VLDO/ LDOA, LDOB, LDOC Line Regulation VLDO*∆VIN LDOA, LDOB, LDOC Power Supply PSRR[A/B/C] Rejection Ratio LDOA, LDOB, LDOC Auto-Discharge RLDO_(DCHG) Resistance AS2Cwire and Logic Control EN/SET, FL_EN, PWMM, EN_LDOA/ VIH B/C Input High Threshold Voltage EN/SET, FL_EN, PWMM, EN_LDOA/ VIL B/C Input Low Threshold Voltage IIN(LKG) EN Input Leakage Current tEN/SET(OFF) EN/SET Input OFF Timeout tEN/SET(LAT) EN/SET Input Latch Timeout tEN/SET(LOW) EN/SET Input LOW Time tENSET(H-MIN) EN/SET Minimum High Time tENSET(H-MAX) EN/SET Maximum High Time Conditions Min ILDO = 1mA to 200mA; TA = 25°C ILDO = 1mA to 200mA; TA = -40°C to +85°C -1.5 -3.0 Typ Max Units 1.5 3.0 % 200 VLDO[A/B/C] ≥ 3.0V; ILDO = 150mA 75 VIN = (VLDO[A/B/C] + 1V) to 5V ILDO[A/B/C] =10mA, 1kHz 2.7V ≤ VIN ≤ 5.5V mA mV 0.09 %/V 50 dB 1.5 kΩ 1.4 V 2.7V ≤ VIN ≤ 5.5V EN/SET = PWMM = EN_LDOA/B/C = IN = 5V 150 -1 0.3 0.4 V 1 500 500 75 μA µs µs µs ns µs 50 75 1. The AAT2866 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls. 2. VDO[A/B/C] is defined as VIN – LDO[A/B/C] when LDO[A/B/C] is 98% of nominal. 6 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Typical Characteristics Flash Efficiency vs. Input Voltage 100 100 90 90 80 80 Efficiency (%) Efficiency (%) Backlight Efficiency vs. Input Voltage 70 60 50 30mA/ch, VF = 3.95V 15mA/ch, VF = 3.5V 4.2mA/ch, VF = 3.4V 40 30 2.7 3.1 3.5 60 50 320mA/ch, VF = 3.25V 160mA/ch, VF = 3.15V 40 3.9 4.3 4.7 5.1 30 2.7 5.5 Input Voltage (V) 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Backlight Current Matching vs. Temperature Charge Pump Output Turn On Characteristic (VIN = 3.6V; 20mA/ch) (VIN = 3.6V; 0mA/ch; COUT = 2.2µF) 22 4.0 VEN/SET (top) (V) 21 20 19 Channel 1 - Channel 6/7 18 2.0 4.0 0.0 3.0 2.0 1.0 17 0.0 16 -40 -15 10 35 60 85 Temperature (°C) Time (50µs/div) Turn On to 1x Mode Flash Turn On to 1.5x Mode Flash (VIN = 4.2V; 300mA/ch) VOUT (2V/div) VFLX (2V/div) (VIN = 3.6V; 300mA/ch) 4 VFL_EN (2V/div) 4 VFL_EN (2V/div) 2 0 VOUT (2V/div) VFLX (2V/div) 4 2 600 0 2 0 4 2 0 600 400 IIN (200mA/div) 400 IIN (200mA/div) 200 0 Time (50µs/div) Output Voltage (bottom) (V) Backlight Output Current (mA) 70 200 0 Time (50µs/div) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 7 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Typical Characteristics Turn On to 2x Mode Flash Turn On to 1x Mode Backlight (VIN = 2.8V; 300mA/ch) 4 VFL_EN (2V/div) VOUT (2V/div) VFLX (2V/div) (VIN = 4.2V; 20mA/ch) 2 0 4 2 0 600 400 IIN (200mA/div) 200 0 Time (50µs/div) EN/SET (2V/div) 0V VCP (2V/div) 0V VBLx (2V/div) 0V IIN (100mA/div) 0A Time (100µs/div) Turn On to 1.5x Mode Backlight Turn On to 2x Mode Backlight (VIN = 3.2V; 20mA/ch) EN/SET (2V/div) VCP (2V/div) VBLx (2V/div) IIN (100mA/div) (VIN = 2.7V; 20mA/ch) EN/SET (2V/div) 0V VCP (2V/div) VBLx (2V/div) 0V 0V 0V 0V IIN (200mA/div) 0A Time (100µs/div) Operating Characteristic (VIN = 3.2V; 20mA/ch Backlight; 1.5x Mode; COUT = 2.2µF) VEN/SET (2V/div) VDIODE (2V/div) IIN (200mA/div) 20 10 0 50 0 Charge Pump Output Voltage (AC coupled) (bottom) (mV) Input Voltage (AC coupled) (top) (mV) (VIN = 3.2V; 20mA/ch) Time (200µs/div) 0A Time (200µs/div) Turn Off from 1.5x Mode Backlight 8 0V -50 Time (500ns/div) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Typical Characteristics Operating Characteristic LDO Load Regulation vs. Output Current 10 0 20 10 0 -10 -20 Time (500ns/div) 1.8 Output Error (%) 20 (VOUT = 1.2V) Charge Pump Output Voltage (AC coupled) (bottom) (mV) Input Voltage (AC coupled) (top) (mV) (VIN = 3.0V; 20mA/ch Backlight; 2x Mode; COUT = 2.2µF) -1.0 60 85 Temperature (°C) 0 -100 2.00 -200 1.90 -300 1.80 -400 1.70 -500 1.60 Time (20µs/div) LDO A/B/C Line Transient Response LDO A/B/C Turn On Characteristic 1.80 1.79 VENLDOX (top) (V) Input Voltage (top) (V) 1.81 4.0 2.0 0.0 1.5 1.0 0.5 0.0 1.78 Time (1ms/div) LDO Output (bottom) (V) 1.82 (VLDO = 1.8V; VIN = 3.6V; CLDO = 2.2µF) LDO Output Voltage (bottom) (V) 3.6 1000 100 (VIN = 3.6V to 4.2V; ILDO = 10mA; VOUT = 1.8V; CLDO = 2.2µF) 4.0 100 200 4.4 10 Load Current (mA) LDO Output Current (top) (mA) LDO Output Voltage Deviatoin (%) -0.5 35 1 LDO Output Voltage (bottom) (V) 0.0 10 -1.2 LDO A/B/C Load Transient Response 0.5 -15 -0.6 (ILDO = 10mA to 200mA; VIN = 3.6V; VLDO = 1.8V; CLDO = 2.2µF) VOUT = 1.8V VOUT = 3.3V -1.5 -40 0.0 (VIN = 3.6V; ILDO = 0mA) 1.0 0.6 -1.8 0.1 LDO A/B/C Output Voltage vs. Temperature 1.5 85°C 25°C -40°C 1.2 Time (20µs/div) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 9 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Typical Characteristics EN/SET, FL_EN, PWMM, EN_LDOA/B/C High Threshold Voltage vs. Input Voltage EN/SET, FL_EN, PWMM, EN_LDOA/B/C Low Threshold Voltage vs. Input Voltage 1.2 VEN/SET(L), VFL_EN(L), VPWMM(L), VEN_LDOA/B/C(L) (V) VEN/SET(H), VFL_EN(H), VPWMM(H), VEN_LDOA/B/C(H) (V) 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 -40°C 25°C 85°C 0.6 0.5 0.8 0.7 0.6 0.5 -40°C 25°C 85°C 0.4 0.3 Input Voltage (V) EN/SET Input Off Timeout vs. Input Voltage 400 500 450 350 400 300 TOFF (µs) TLAT (µs) 0.9 EN/SET Input Latch Timeout vs. Input Voltage 250 200 -40°C 25°C 85°C 150 100 2.7 1.0 0.2 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 0.4 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 Input Voltage (V) 1.1 3.1 3.5 3.9 4.3 Input Voltage (V) 4.7 5.1 350 300 250 200 -40°C 25°C 85°C 150 100 2.7 5.5 3.1 3.5 3.9 4.3 4.7 Input Voltage (V) 10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 5.1 5.5 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Functional Block Diagram IN IN C1C1+ C2- LDOA 1x/1.5x/2x Tri -mode Charge Pump C2+ LDOB OUT LDOC 8 REF BL1 EN/SET 5 FL_EN EN_LDO A/B/C Main Backlight Current Control BL2 BL3 BL4 Control Logic 5 PWMM 4 PGND Sub Backlight Current Control Flash Control BL5 BL6 BL7/FL2 FL1 AGND Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 11 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit Functional Description The AAT2866 is a highly integrated backlight and photoflash driver family with three LDO regulators. The charge pump LED driver powers the backlight and flash LEDs from the 2.7V to 5.5V input voltage. The LDO regulators get their power from the same input and produce regulated output voltages between 1.2V and 3.3V. Control of the LEDs and the LDO output voltages are through an AS2Cwire serial interface for easy programming. In addition, BL1-BL6 (AAT2866) or BL1-BL7 (AAT2866-3) LED current can be controlled via an external PWM signal. LED Drivers The AAT2866 drives six backlight LEDs up to 31mA each and a total of 600mA flash current through two channels. The LEDs are driven from a charge pump to insure that constant current is maintained for all possible LED forward voltages over the entire battery voltage range. The charge pump automatically switches from 1x, to 1.5x, to 2x modes and back to maintain the LED current while minimizing power loss for high efficiency. The charge pump operates at the high 1MHz switching frequency allowing the use of small 1μF ceramic capacitors. Each individual LED is driven by a current sink to GND, allowing individual current control with high accuracy over a wide range of input voltages and LED forward voltages while maintaining high efficiency. The charge pump is controlled by the voltage across the LED current sinks. When any one of the active backlight current sink voltages drops below 200mV or the flash current sink drops below 450mV, the charge pump goes to the next higher mode (from 1x to 1.5x or from 1.5x to 2x mode) to maintain sufficient LED voltage for constant LED current. The AAT2866 continuously monitors the LED forward voltages and uses the input voltage to determine when to reduce the charge pump mode for better efficiency. There is also a 300mV mode-transition hysteresis that prevents the charge pump from oscillating between modes. LED Current Control Both the backlight and flash LED currents are controlled through the AS2Cwire serial interface. The backlight LED current can be set between 0.5mA and 31mA in approximately 1mA steps while the flash LED current can be set between 0 to 300mA in 20mA steps for each channel. 12 The backlight LED currents match to within 3% while the flash LED currents match to within 5%. To eliminate the latency of the AS2Cwire serial interface, the flash LED is enabled through a dedicated input, FL_ EN. The AAT2866 also includes a safety timer that prevents overstress of the flash LEDs. This is important because many flash LEDs operate for a brief period beyond their steady-state operating limitations. If the flash driving hardware and/or software fails to turn the LED off, the safety timer insures that the LED or other circuitry is not damaged. Both the backlight and flash LED currents are programmed through the AS2Cwire serial interface including the flash safety timer. See the “AS2Cwire Serial Interface Programming” section for more information on setting the LED currents. PWM Controlled Dimming As an alternative to digital dimming via the AS2Cwire serial interface, the AAT2866 also provides an additional pin, PWMM, which allows the user to control BL1-BL6 (AAT2866) or BL1-BL7 (AAT2866-3) or the Main BL1-BL4 (AAT2866) or BL1-BL5 (AAT2866-3) (optional, when MEQS is deactivated) backlight LEDs with a PWM signal. The Sub backlight channels BL5-BL6 (AAT2866) or BL6BL7 (AAT2866-3) current is set by AS2Cwire interface. The PWM signal will modulate the LED current set by AS2Cwire programming or the AAT2866 default current. In this mode the minimum PWM frequency is 60Hz. PWM frequencies as high as 100kHz can be used. LDO Regulators The AAT2866 family includes three low dropout (LDO) linear regulators. These regulators are powered from the battery and produce fixed output voltages set through the AS2Cwire serial interface. The output voltage can be set to one of 16 output voltages between 1.2V and 3.3V. The LDO regulators can be turned on/off with the external enable pin EN_LDOA/B/C. Additionally, the AS2Cwire interface allows the LDO regulators to be enabled independently when the EN_LDOA/B/C pin is pulled high. All LDO regulators require only small 2.2μF ceramic output capacitors for stability. If improved load transient response is required, larger-valued capacitors can be used without stability degradation. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202262A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 10, 2012 DATA SHEET AAT2866 Backlight/Flash LED Driver and Triple LDO Lighting Management Unit AS2Cwire Serial Interface Protocol changing the address, or writing to an address other than the default after shutdown. Address 0 is the default address after shutdown. If the part is enabled with only data edges and no address, then Address 0 will be programmed and LED Backlight channels BL1-BL6 (AAT2866) or BL1-BL7 (AAT2866-3) will be enabled according to the number of data edges applied. The AAT2866 is dynamically programmable by the AS2Cwire single-wire interface. AS2Cwire records rising edges detected at the EN/SET pin to address and load the data registers. The timing diagram in Figure 1 shows the typical transmission protocol. AS2Cwire latches data or address after the EN/SET input has been held high for time tLAT (500µs). Address or data is differentiated by the number of EN/SET rising edges. Since the data registers are 4 bits each, the differentiating number of pulses is 24 or 16, so that Address 0 is identified by 17 rising edges, Address 1 by 18 rising edges, Address 2 by 19 rising edges, etc. Data is set to any number of rising edges between 1 and 16. A typical write protocol is a burst of EN/SET rising edges identifying a particular address, followed by a pause with EN/SET held high for the tLAT time-out period, then a burst of rising edges signifying data, and another tLAT timeout after the data has been sent. Once an address is set, multiple writes to that address are allowed since the address is not reset after each write. Address edges are needed when When EN/SET is held low for a time longer than tOFF (500µs), the AAT2866 enters shutdown mode and draws less than 1µA of current from IN. At shutdown, the data and address registers are reset to 0. AS2Cwire Serial Interface Programming The AAT2866’s AS2C programming Address registers are listed in Table 1. There are 13 active Address registers; four control the three LDOs, four control the backlight LED configuration/control, two control the flash current and timer control, two are used to individually disable each backlight or flash channel, and one is reserved for test purposes. Address Data THI TLO TLAT TLAT EN/SET 1 Address 2 17 18 1 0 2... n