DATA SHEET AAT3176 500mA LED Flash Driver General Description Features The AAT3176 is a high output current, high efficiency, low noise, low profile charge pump converter IC, ideal for multi-function LED photo-flash applications where solution cost, size, and efficiency are critical. The charge pump is capable of delivering up to 500mA of output current and can be easily programmed in 16 steps with a single GPIO output through Skyworks' S2Cwire™ (Simple Serial Control) interface. This allows smooth transitions and flexible adjustment of brightness in flash or other lighting modes. Operating at a fast 1MHz switching frequency, the dual-mode (1x/2x) operation of the internal charge pump offers excellent power efficiency for both flash and movie modes and combined with a low external parts count (one 1μF flying capacitors and small bypass capacitors at VIN and OUT), the AAT3176 is ideally suited for small, battery-powered applications. • 2.7V to 5.5V Supply Voltage Range • Up to 500mA Output Drive Capability at 3.6V VIN • Flexible Brightness Control ▪ 16 Step Output Current by S2Cwire • Separate External Resistors to Set Maximum Flash and Movie-Mode Current • Dual Mode 1x/2x Charge Pump • < 1.0μA in Shutdown • Small Application Circuit • Automatic Soft-Start Limits Inrush Current • Open- and Short-Circuit Protection • Thermal Shutdown Protection • -40 to +85°C Temperature Range • 10-pin TDFN2.2x2.2 Package Applications The maximum current for both Flash and Movie mode is set by two independent external resistors. The MODE pin is adopted to select the LED current between Movie (Torch) and Flash mode. • • • • Digital Still Cameras (DSC) LED Photo Flash/Torch Mobile Handsets PDAs and Notebook PCs The AAT3176 has a thermal management system to protect the device in the event of short-circuit, open-circuit, and over-temperature condition. Built-in soft-start circuitry prevents excessive in-rush current during startup. The shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1.0μA. The AAT3176 is available in the 2.2 x 2.2mm Pb-free 10-pin TDFN package. Typical Application C1 1µF C1+ 2.7V to 5.5V CIN 4.7µF EN Flash Movie C1VOUT VIN COUT 2.2µF AAT3176 FL RSETF RSETM EN/SET MODE GND Flash LED RM RF Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 1 DATA SHEET AAT3176 500mA LED Flash Driver Pin Descriptions Pin # Symbol 1 2 3 4 5 C1+ VOUT FL RSETF RSETM 6 MODE 7 EN/SET 8 9 10 EP GND C1VIN Description Flying capacitor C1 positive terminal. Connect a 1.0 μF capacitor between C1+ and C1-. Charge-pump output. Requires 2.2uF bypass capacitor to ground. Output current source. Connect the flash LED anode to this pin. Connect a resistor to GND to set maximum FLASH output current. Connect a resistor to GND to set maximum MOVIE-MODE output current. Selects between Flash and Movie Mode: When MODE is HIGH, it is in Flash Mode with RSETF for maximum current. When MODE is LOW, it is in Movie Mode with RSETM for maximum current . Charge Pump enable / set input control pin. When in the low state, the AAT3176 is shut down, and consumes less than 1μA. When connected logic high level, the AAT3176 is active. This pin must be connected. Ground connection and flash LED cathode. Flying capacitor C1 negative terminal. Input power supply pin. Requires 4.7μF bypass capacitor to ground. Exposed pad. Connect directly to ground beneath the package. Pin Configuration TDFN2.2x2.2-10 (Top View) C1+ VOUT FL RSETF RSETM 2 1 10 2 8 3 8 4 7 5 6 VIN C1GND EN/SET MODE Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Absolute Maximum Ratings1 TA = 25°C unless otherwise noted. Symbol VIN VEN Description Input Voltage EN to GND Voltage Maximum EN to Input Voltage Maximum DC Output Current2 Maximum Peak Output Current (lasting 1 second) Maximum Junction Operating Temperature Storage Temperature Range Maximum Soldering Temperature (at leads, 10 sec) VEN(MAX) IOUT TJ TS TLEAD Value Units -0.3 to 6.0 -0.3 to 6.0 VIN + 0.3 150 550 -40 to 150 -65 to 150 300 V V V mA mA Value Units 71.4 1.4 °C/W W °C Thermal Information3 Symbol JA PD Description Thermal Resistance Maximum Power Dissipation (TA = 25°C) 4 1. 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. 2. Based on long-term current density limitation. 3. Mounted on an FR4 board. 4. Derate 71.4mW/°C above 25°C. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 3 DATA SHEET AAT3176 500mA LED Flash Driver Electrical Characteristics1 VIN = 3.6V; CIN = 4.7μF; COUT = 2.2μF; CFLY = 1μF; RSETF = 21kΩ; RSETM = 105kΩ; TA = -40°C to 85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Conditions Power Supply VIN Input Voltage Range VOUT (max) Maximum Output Voltage IINQ ISHDN(MAX) IIN_Short IDM IDF Input Operating Current VIN Pin Shutdown Current Input Current at Short Circuit Movie Output Current Flash Output Current IOUT(MAX) Maximum Output Current ILED/ISET LED Current Ratio FCLK Charge Pump Clock Frequency in 2X Mode Soft-Start Time TSS EN/SET, MODE VRSET RSETF and RSETM Pin Voltage VEN/MODE(L) EN/MODE Threshold Low EN/MODE Threshold High VEN/MODE(H) ILEAK EN/SET, MODE input leakage S2C Control TEN/SET LO EN/SET Low Time TEN/SET HI(MIN) Minimum EN/SET High Time TEN/SET HI(MAX) Maximum EN/SET High Time TOFF EN/SET Off Timeout TLAT EN/SET Latch Timeout Thermal Protection Thermal Shutdown Threshold TSD Thermal Shutdown Hysteresis THYS Min Typ 2.7 EN/SET = IN, 1x mode, IF = 100mA EN/SET = IN, 2x mode, IF = 100mA EN = GND VF = 0V RSETM = 105kΩ RSETF = 21kΩ, TA = 25°C RSETF = 21kΩ, VIN = 3.0V VF = 3.6V Max Units 5.5 V V 5.5 0.5 3.0 mA 1.0 450 25 100 500 350 550 500 0.5 8652 1 100 1.5 1.22 0.4 1.4 -1 1 0.3 75 50 75 500 500 140 15 μA mA mA mA mA mA MHz μs V V V μA μs ns μs μs μs O C 1. The AAT3176 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. 4 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Typical Characteristics Quiescent Current vs. Input Voltage Shutdown Current vs. Input Voltage (VF = 3.6V; RSET = 105kΩ) (VF = 3.6V; EN = 0V) Quiescent Current (mA) -40°C 25°C 85°C 0°C 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 Shutdown Current (μA) 1 5.0 -40°C 0°C 25°C 85°C 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0.0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 2.7 3.1 3.5 Input Voltage (V) Efficiency vs. Input Voltage 100% Efficiency (%) 5.1 5.5 80% 70% 60% 50% VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90% Efficiency (%) VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90% 40% 80% 70% 60% 50% 40% 3.1 3.5 3.9 4.3 4.7 5.1 30% 2.7 5.5 3.1 3.5 Input Voltage (V) 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Efficiency vs. Input Voltage Efficiency vs. Input Voltage (RSETF = 35.7kΩ; IF = 300mA) (RSETF = 21kΩ; IF = 500mA) VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90% 80% 70% 60% 50% 40% 100% VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90% Efficiency (%) 100% Efficiency (%) 4.7 (RSETF = 52.3kΩ; IF = 200mA) 100% 30% 2.7 4.3 Efficiency vs. Input Voltage (RSET = 105kΩ; IF = 100mA) 30% 2.7 3.9 Input Voltage (V) 80% 70% 60% 50% 40% 3.1 3.5 3.9 4.3 Input Voltage (V) 4.7 5.1 5.5 30% 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 5 DATA SHEET AAT3176 500mA LED Flash Driver LED Current vs. Input Voltage LED Current vs. Input Voltage (RSET = 105kΩ; IF = 100mA) (RSET = 52.3kΩ; IF = 200mA) 120 120 115 115 110 110 105 105 IF (mA) IF (mA) Typical Characteristics 100 95 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90 85 3.1 3.5 3.9 4.3 4.7 5.1 95 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 90 85 80 2.7 100 80 2.7 5.5 3.1 3.5 Input Voltage (V) 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) LED Current vs. Input Voltage LED Current vs. Input Voltage (RSET = 35.7kΩ; IF = 300mA) (RSET = 21kΩ; IF = 500mA) 400 600 550 350 500 IF (mA) IF (mA) 300 250 200 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 150 100 2.7 3.2 3.7 4.2 4.7 450 400 350 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 300 250 200 2.7 5.2 3.1 3.5 Input Voltage (V) 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Maximum Output Current vs. Input Voltage Maximum Output Current vs. Input Voltage (RSETM = 105kΩ; VF = 3.6V) (RSETF = 21kΩ; VF = 3.6V) 140 550 130 500 IF_MAX (mA) IF_MAX (mA) 120 110 100 90 80 -40°C 25°C 85°C 70 60 2.7 3.1 3.5 3.9 4.3 Input Voltage (V) 6 4.7 5.1 5.5 450 400 -40°C 25°C 85°C 350 300 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 Input Voltage (V) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 5.2 5.4 DATA SHEET AAT3176 500mA LED Flash Driver Typical Characteristics EN/MODE Threshold High vs. Temperature EN/MODE Threshold Low vs. Temperature 1.4 1.4 1.3 1.2 1.2 1.0 VIL (V) VIH (V) 1.1 1.0 0.9 0.8 0.7 0.5 0.4 -40 -15 10 35 60 0.6 0.4 VIN = 2.7V VIN = 3.6V VIN = 4.2V 0.6 0.8 VIN = 2.7V VIN = 3.6V VIN = 4.2V 0.2 0.0 -40 85 -15 10 Temperature (°C) 35 60 85 Temperature (°C) LED Current vs. RSET EN Leakage Current vs. Input Voltage (VF = 3.6V; VEN = 5.5V; RSET = 21kΩ) 0.8 EN Leakage Current (μA) LED Current (mA) 600 RSETF RSETM 500 400 300 200 100 0.7 0.6 0.5 0.4 0.3 -40°C 0°C 25°C 85°C 0.2 0.1 0.0 0 0 50 100 150 200 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) RSET (kΩ) Oscillator Frequency vs. Input Voltage Frequency (MHz) 1.10 1.05 1.00 -40°C 0°C 25°C 85°C 0.95 0.90 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 7 DATA SHEET AAT3176 500mA LED Flash Driver Typical Characteristics LED Current 7.5mA to 100mA Transient LED Current 100mA to 7.5mA Transient (VIN = 5.0V; VF = 3.6V; RSET = 105kΩ) (VIN = 5.0V; VF = 3.6V; RSET = 105kΩ) VEN (2V/div) VEN (2V/div) 100mA 100mA IF (50mA/div) IF (50mA/div) Time (40μs/div) Time (40μs/div) LED Current 40mA to 500mA Transient LED Current 500mA to 40mA Transient (VIN = 5.0V; VF = 3.6V; RSET = 21kΩ) (VIN = 5.0V; VF = 3.6V; RSET = 21kΩ) VEN (2V/div) VEN (2V/div) 500mA 500mA IF (200mA/div) IF (200mA/div) Time (40μs/div) 8 Time (40μs/div) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Functional Block Diagram C+ C- VIN 1MHz Oscillator Charge Pump OUT Soft Start Control FL EN/SET System Control; S2CWire; Timing GND RSETF MODE RSETM Functional Description The AAT3176 is a high efficiency, low noise, 1x/2x regulating charge pump device is intended for photo flash LED applications. The AAT3176 requires only 3 external components: one 1.0μF ceramic capacitor for the charge pump flying capacitor, one 4.7μF ceramic capacitor for CIN, and one 2.2μF to 4.7 μF ceramic capacitor for COUT filtering. The charge pump is designed to deliver up to 500mA load current at VIN = 3.6V. The dual mode charge pump section contains soft start circuitry to prohibit an excessive in rush current during start up. System efficiency is maximized with a 1x/2x mode, dual mode charge-pump topology. The internal clock oscillator frequency of 1MHz allows the use of small external components. Depending upon the variation of load current (at different modes), input voltage, and LED forward voltage, the charge pump will operate in 1x or 2x mode to generate the output voltage required to power the load for the required current. This results in significant power savings over pure voltage doubling architectures, especially when the LEDs are operated at lower current levels in movie, viewing, or flash modes. The AAT3176 also includes open- and short-circuit protection to deal with fault situations. When the flash LED is not connected (an open fault occurs), the VOUT will be limited to 6V; When a flash LED short fault occurs, the total input current is limited to typical 25mA. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 9 DATA SHEET AAT3176 500mA LED Flash Driver S2Cwire Serial Interface The AAT3176 utilizes Skyworks’ single-wire S Cwire interface to enable/disable the charge pump and adjust the output current level to one of sixteen different current levels. Each DATA defines the output current as a percentage of the maximum current set by the resistor at the RSET pin, as detailed in Table 1. 2 The S2Cwire interface records rising edges of the EN/SET pin and decodes them into 16 individual current level settings, with DATA 1 reserved for maximum current. Once EN/SET has been held in the logic high state for time TLAT, the programmed current is set at the current source outputs. For subsequent current level programming, the number of rising edges corresponding to the desired DATA must be entered on the EN/SET pin. Figure 1 shows the S2CwireTM interface timing. DATA Output Current (% of IMAX) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 100.0% 89.1% 79.4% 70.8% 63.1% 56.2% 50.1% 44.7% 39.8% 35.5% 31.6% 28.2% 25.1% 22.4% 20.0% 7.5% Table 1: Output Current at Different S2Cwire DATA.1 When EN/SET is held low for an amount of time greater than TOFF, the AAT3176 enters shutdown mode and draws less than 1μA from VIN. Data and Address registers are reset to 0 during shutdown. S2Cwire Serial Interface Timing THI TLO TOFF T LAT EN/SET 1 2 n-1 0 Data Reg n ≤ 16 n 0 Figure 1: S2Cwire Interface Timing. 1. The flash LED accuracy is compromised at high DATA settings. 10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Application Information VIN (5V/div) Flash and Movie Mode LED Current Setting The AAT3176 has two independent LED current setting pins for LED current in flash and movie mode: RSETF and RSETM. The MODE pin is designed to select which current set flows through the LED. When MODE is high, the current set by RSETF is the maximum LED current; when MODE is low, the maximum current is set by RSETM. The calculation method of the LED current set resistor value RSET is the same for either mode and can be calculated using the following formula: RSETF = RSETM = 1.22 · 8652 ILED Table 2 shows some examples of 1% standard metal film resistor values for different maximum LED currents (DATA = 1) in movie and flash mode. RSETM (kΩ) Maximum LED Current (mA) RSETF (kΩ) Maximum LED Current (mA) 210.0 174.0 150.0 130.0 118.0 105.0 50 60 70 80 90 100 105.0 69.8 52.3 42.2 35.7 30.1 26.1 23.7 21.0 100 150 200 250 300 350 400 450 500 Table 2: Maximum LED Current RSETM and RSETF Example. LED current can be set to levels lower than maximum via S2C DATA transferred through the EN/SET pin, corresponding to percentage of the maximum setting value. In movie mode, continuous high level of EN/SET lights the LED light continuously at the programmed current. In flash mode, EN/SET high level duration controls flash time; the maximum flash time is 1 second for 500mA LED current limited by the thermal characteristics of the package. Figure 2 shows the operating waveform of the AAT3176 driving an LED for 500ms flash time in flash mode with 500mA LED current at 3.6V VIN (2x mode). IIN (1A/div) VF (2V/div) ILED (1A/div) VC1 (5V/div) VRSETF (2V/div) Time (100ms/div) Figure 2: AAT3176 Operating Waveform at 500mA LED Current with 500ms Flash Time (RSETF = 21kΩ). Thermal Considerations The AAT3176 is designed to deliver continuous LED current in movie mode. The limiting characteristic for maximum safe operating output LED current is package power dissipation. In order to obtain high operating currents, careful device layout and circuit operating conditions must be taken into account. The following discussions assume that the AAT3176 is mounted on a printed circuit board utilizing the minimum recommended footprint as stated in the “Printed Circuit Board Layout Recommendations” section of this datasheet. At any given ambient temperature (TA), the maximum package power dissipation can be determined by the following equation: PD(MAX) = (TJ(MAX) - TA) θJA The AAT3176 is available in the TDFN2.2x2.2-10 package, which has 71.4°C/W of thermal resistance (θJA). With 125°C TJ(MAX), its PD(MAX) is 1.4W. The maximum power dissipation occurs when the mode transfers from 1x to 2x. If the die temperature rises above the thermal limit of 140°C, the internal thermal protection circuit activates to shut down the charge pump and recovers when the die temperature drops below 125°C. To avoid entering thermal protection in flash mode at the 500mA high flash LED current setting, the flash time should not exceed 1 second at 25°C ambient temperature. Longer flash time causes the junction temperature to increase quickly, causing thermal shutdown. The LED current recovers automatically when the junction temperature decreases. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 11 DATA SHEET AAT3176 500mA LED Flash Driver In movie mode, maximum continuous current value is not limited by the package thermal resistance but by the integrated metal current density. The maximum value should not exceed 150mA. ing forward voltage VF in the range of 4.2V to 1.5V. Low forward voltage (VF) flash LED may make the 1x/2x mode automatically transfer voltage point lower and get higher efficiency at the mode transfer input voltage. Charge Pump Efficiency Capacitor Selection The power conversion efficiency of the AAT3176 depends on the charge pump mode. By definition, device efficiency is expressed as the output power delivered to the LED divided by the total input power consumed. Careful selection of the three external capacitors CIN, C1, and COUT is important because they will affect turn-on time, output ripple and transient performance. Optimum performance is obtained when low ESR ceramic capacitors are used; in general, low ESR may be defined as less than 100mΩ. A capacitor value of 1μF for all three capacitors is a good starting point when choosing capacitors; a 2.2μF to 4.7μF value is suitable for input and output capacitance. η= POUT PIN When the input voltage is sufficiently greater than the LED forward voltage, the device optimizes efficiency by operating in 1x mode. In 1x mode, the device is working as a bypass switch and passing the input supply directly to the output. Due to the very low 1x mode quiescent current, the input current nearly equals the current delivered to the LED. Further, the low-impedance bypass switch introduces negligible voltage drop from input to output. The power conversion efficiency can be approximated by: η= VF · ILED VF ≈ VIN · IIN VIN The AAT3176 maintains optimized performance and efficiency by detecting. When the input voltage is not sufficient to sustain LED current, the device automatically switches to 2x mode. For ideal conversion, the 2x mode efficiency is given by: η= VF VF · ILED VF · ILED = ≈ VIN · IIN VIN · 2 · ILED 2 · VIN LED Selection A good LED lighting application circuit not only determined by the LED driver but also the LED selected. A higher luminous efficacy LED emits a higher amount of luminous flux (lumens) for a given power. Most LED manufacturers' datasheets provide the luminous efficacy by the luminous flux curve (LED forward current vs luminous flux). From the luminous flux curve, increasing the LED forward current may increase the LED light; increased LED forward current also increases LED forward voltage with higher rating. The AAT3176 is designed to drive high-intensity white LEDs. It is particularly suitable for LEDs with an operat- 12 Ceramic composition capacitors are highly recommended over all other types of capacitors for use with the AAT3176. Ceramic capacitors offer many advantages over their tantalum and aluminum electrolytic counterparts. A ceramic capacitor typically has very low ESR, is lowest cost, has a smaller PCB footprint and is nonpolarized. Low ESR ceramic capacitors help to maximize charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage. Equivalent Series Resistance (ESR) ESR is an important characteristic to consider when selecting a capacitor. ESR is resistance internal to a capacitor, which is caused by the leads, internal connections, size or area, material composition, and ambient temperature. Capacitor ESR is typically measured in milliohms for ceramic capacitors and can range to more than several ohms for tantalum or aluminum electrolytic capacitors. Printed Circuit Board Layout Recommendations When designing a PCB for the AAT3176, the key requirements are: 1. Place the flying capacitor CP as close to the chip as possible; otherwise 2x mode performance will be compromised. 2. Place input and output decoupling capacitors as close to the chip as possible to reduce switching noise and output ripple. 3. Connect the exposed pad to the GND plane to achieve the best power dissipation. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Schematic and Layout J1 CP 1μF U1 AAT3176 1 C1+ 2 VOUT 3 FL 4 RSETF 5 RSETM R7 0 DC+ AAT3176 White LED Driver VIN C1GND EN/SET MODE 10 9 8 7 6 MODE MODE VIN 0 D1 DC- C OUT 2.2μF EP RSETF 21k RSETM 105K JP1 C IN 4.7μF S2Cwire Microcontroller EN/SET R6 20K S2C R1 1K R2 1K R3 1K 1 2 3 DOWN 4 U2 PIC12F675 VDD VSS GP0 GP5 GP4 GP1 GP3 GP2 8 7 MODE R5 C1 0.1uF 1K LED2 Red 6 5 R4 1K UP LED1 Green CYCLE Figure 3: AAT3176 Evaluation Board Schematic. Figure 4: AAT3176 Evaluation Board Layout Top Layer. Figure 5: AAT3176 Evaluation Board Layout Bottom Layer. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 13 DATA SHEET AAT3176 500mA LED Flash Driver Component Part Number Description Manufacturer U1 U2 C1 CIN COUT CP CYCLE, UP, DOWN AAT3176IDH PIC12F675 GRM188R71C104K GRM188R60J475K GRM188R61A225K GRM188R71C105K 6*6*5 Skyworks Microchip D1 FCW401Z4 LED1 LED2 R1 - R5 R6 R7 RSETF RSETM 0805KGCT 0805KRCT RC0603FR-071KL RC0603FR-0720KL RC0603FR-070RL RC0603FR-0721KL RC0603FR-07105KL 500mA LED Flash Driver with Flash and Movie Mode 8-Pin Flash-Based 8-Bit CMOS Microcontrollers Cap Ceramic 0.1μF 0603 X7R 16V 10% Cap Ceramic 4.7μF 0603 X5R 6.3V 10% Cap Ceramic 2.2μF 0603 X5R 10V 10% Cap Ceramic 1μF 0603 X7R 16V 10% 12V 50mA Pushbutton Max 300mA Forward Current, Max 1500mA/300ms Peak Forward Current Green LED 0805 Red LED 0805 Res 1KΩ 1/10W 1% 0603 SMD Res 20KΩ 1/10W 1% 0603 SMD Res 0Ω 1/10W 1% 0603 SMD Res 21KΩ 1/10W 1% 0603 SMD Res 105KΩ 1/10W 1% 0603 SMD Murata E-LT Seoul HB Yageo Table 3: AAT3176 Evaluation Board Bill of Materials (BOM). 14 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 DATA SHEET AAT3176 500mA LED Flash Driver Ordering Information Package Part Marking1 Part Number (Tape and Reel)2 TDFN2.2x2.2-10 8HXXY AAT3176IDH-T1 Skyworks Green™ products are compliant with all applicable legislation and are halogen-free. For additional information, refer to Skyworks Definition of Green™, document number SQ04-0074. Package Information TDFN2.2x2.2-10 2.200 ± 0.050 Detail "A" 0.400 ± 0.050 0.180 ± 0.050 1.700 ± 0.050 2.200 ± 0.050 Index Area 0.900 ± 0.050 Top View 0.400 BSC Bottom View 0.500 ± 0.050 0.203 REF 0.750 ± 0.050 Pin 1 Indicator (optional) Detail "A" Side View All dimensions in millimeters. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. 3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection. Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved. Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes. No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. 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Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters. Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202102A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012 15