PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver General Description Features The AAT3104 is a charge-pump based, current-source white LED driver capable of driving one to four LEDs up to 30mA, each. It automatically switches between 1x mode and 2x mode to maintain the highest efficiency and optimal LED current accuracy and matching. • • • • • The AAT3104 charge pump’s 1x mode (bypass mode) has very low resistance allowing LED current regulation to be maintained with input supply voltage approaching the LED forward voltage. LED brightness is controlled using AnalogicTech’s patented S2Cwire™ single wire interface. The AAT3104 is available in a 2x2mm 10-lead SC70JW-10 package. • • • • • • Drives up to 4 LEDs at up to 31mA each Automatic Switching Between 1x and 2x Modes 1MHz Switching Frequency Linear LED Output Current Control Single-wire, S2Cwire Interface AAT3104-1: 16-step AAT3104-2: 32-step ±10% LED Output Current Accuracy ±3% LED Output Current Matching Low-current Shutdown Mode Built-in Thermal Protection Automatic Soft-start Available in 2x2mm SC70JW-10 Package Applications • • • • Cordless Phone Handsets Digital Cameras Mobile Phone Handsets MP3 and PMP Players Typical Application Input Voltage 2.7V to 5.5V IN OUT C OUT 1µF C+ C IN 1µF AAT3104 CP 1µF D1 D2 CEN/SET S2Cwire Interface 3104.2008.09.1.0 D3 EN/SET D4 GND www.analogictech.com 1 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Pin Descriptions Pin# Name 1 D2 2 D1 3 OUT 4 5 6 CC+ GND 7 EN/SET 8 IN 9 D4 10 D3 Description LED2 Current Source Output. D2 is the output of LED2 current source. Connect LED2’s anode to D2 and its cathode to GND. LED1 Current Source Output. D1 is the output of LED1 current source. Connect LED1’s anode to D1 and its cathode to GND. Charge Pump Output. OUT is the output of the charge pump. Bypass OUT to GND with a 1μF or larger ceramic capacitor. Charge Pump Capacitor Negative Node. Charge Pump Capacitor Positive Node. Connect a 1μF ceramic capacitor between C+ and C-. Analog Ground. Connect this pin to the system’s analog ground plane. LED Enable and serial control input. EN/SET is the ON/OFF control for the LED and the S2Cwire digital input for the AAT3104-1/-2 to control serially the LED brightness according to the maximum current. Power source input. Connect IN to the power source, typically the battery. Bypass IN to GND with a 1μF or larger ceramic capacitor. LED4 Current Source Output. D4 is the output of LED4 current source. Connect LED4’s anode to D4 and its cathode to GND. LED3 Current Source Output. D3 is the output of LED3 current source. Connect LED3’s anode to D3 and its cathode to GND. Pin Configuration SC70JW-10 (Top View) D2 D1 OUT CC+ 2 1 10 2 9 3 8 4 7 5 6 D3 D4 IN EN/SET GND www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Absolute Maximum Ratings1 Symbol VIN, VOUT, VC+, VC-, VD1...4 VEN/SET TS TJ TLEAD Description IN, C+, C-, OUT, D1, D2, D3, and D4 Pin Voltages to GND EN/SET Pin Voltage to GND Storage Temperature Range Operating Junction Temperature Range Maximum Soldering Temperature (at leads, 10 sec) Value Units -0.3 to 6.0 V -0.3 to VIN + 0.3 -65 to 150 -40 to 150 300 V °C °C °C Value Units 625 160 mW °C/W Thermal Information Symbol PD θJA Description Maximum Power Dissipation2, 3 Maximum Thermal Resistance3 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. Mounted on an FR4 circuit board. 3. Derate 6.25mW/°C above 40°C ambient temperature. 3104.2008.09.1.0 www.analogictech.com 3 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Electrical Characteristics1 IN = EN = 3.6V, CIN = 1μF, COUT = 1μF, C1 = 1μF, TA = -40°C to 85°C unless otherwise noted. Typical values are at TA = 25°C. Symbol Description Conditions Input Power Supply VIN Input Voltage Range Iq Quiescent Current IIN Typ Max Units 5.5 6 V mA 3.5 mA 6 mA 2.7 No Load Operating Current IIN(SHDN) Input Shutdown Current Charge Pump Section IOUT OUT Maximum Output Current VOUT Charge Pump Output Voltage fOSC Charge Pump Oscillator Frequency VIN_(TH) Charge Pump Mode Hysteresis tOUT LED Output Current Start-up Time AAT3104-1/-2: LED Current Source Outputs D1 – D4 Current Accuracy ID_(MAX) (AAT3104-1 only) D1 – D4 Current Accuracy ID_(MAX) (AAT3104-2 only) ΔID_(MAX) D1 – D4 Current Matching D1 – D4 Current Accuracy ID_(DATA15) (AAT3104-1 only) D1 – D4 Current Accuracy ID_(DATA29) (AAT3104-2 only) VD_(TH) Min D1- D4 Charge Pump Mode Transition Threshold AAT3104-1/-2: EN/SET and S Cwire Control VENH EN/SET Input High Threshold Voltage VENL EN/SET Input Low Threshold Voltage IEN(LKG) EN/SET 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 IN = 5.5V, EN = IN, VD1 = VD2 = VD3 = 0V IN = 5.5V, EN = IN, ID1 = ID2 = ID3 = ID4 = FS, VD1 = VD2 = VD3 = VD4 = IN – 1.5V, Exclude IDN current, 1x mode Operating, ID1 = ID2 = ID3 = ID4 = OPEN, 2x mode EN/SET = GND 1 μA 0.6 150 5 0.8 150 190 DATA = 1, VIN – VF = 1.5V 27 30 33 mA DATA = 1, VIN – VF = 1.5V 28 31 34 mA DATA = 1, VIN – VF = 1.5V -3 +3 % DATA = 15, VIN – VF = 1.5V 1.6 2.0 2.4 mA DATA = 29, VIN – VF = 1.5V 1.6 2.0 2.4 mA When charge pump is on ID1 = ID2 = ID3 = ID4 =30mA EN/SET =IN ID1 = ID2 = ID3 = ID4 = 30mA, VIN – VD1 is measured ID1 = ID2 = ID3 = ID4 = 20mA, VIN – VD1 is measured 1.05 250 mA V MHz mV μs 380 mV 350 mV 2 1.4 EN/SET = IN = 5V 0.4 1 500 500 75 -1 0.3 50 75 V V μA μs μs μs ns μs 1. The AAT3104 is guaranteed to meet performance specification over the -40°C to 85°C operating temperature range and are assured by design, characterization and correlation with statistical process controls. 4 www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Typical Characteristics VIN = 3.6V, CIN = COUT = C1 = 1μF; TA = 25°C, unless otherwise noted. VLED (2V/div) 1X Mode Turn-On Waveform 2X Mode Turn-On Waveform (VIN = 4.2V; Load = 120mA) (VIN = 3.6V; Load = 120mA) VLED (2V/div) 0 0 IIN (200mA/div) 0 IIN (250mA/div) 0 VOUT (2V/div) 0 VOUT (2V/div) 0 EN (1V/div) 0 EN (1V/div) 0 Time (200µs/div) Time (200µs/div) 2X Mode Turn-Off Waveform 2X Mode Output Ripple (VIN = 3.6V; Load = 120mA) (VIN = 3.6V; Load = 120mA) IIN (250mA/div) VOUT (AC Coupled) (20mV/div) 0 VLED (2V/div) 0 EN (1V/div) 0 VIN (AC Coupled) (5mV/div) 0 0 Time (200µs/div) 1mA to 30mA LED Current Step 30mA to 1mA LED Current Step (VIN = 4.2V) (VIN = 4.2V) VLED 2V/div IIN 200mA/div VOUT 2V/div EN 1V/div Time (0.4µs/div) VLED (2V/div) 0 IIN (200mA/div) VOUT (2V/div) 0 0 0 0 0 EN (1V/div) 0 0 Time (80µs/div) 3104.2008.09.1.0 Time (80µs/div) www.analogictech.com 5 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Typical Characteristics VIN = 3.6V, CIN = COUT = C1 = 1μF; TA = 25°C, unless otherwise noted. Current Matching vs. Temperature Efficiency vs. Input Voltage (AAT3104-2; Code = 1) (ILED = 31mAx4; Voltage Sweep Upwards) 33.0 90 D1 D2 D3 D4 32.0 31.5 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 80 Efficiency (%) Current (mA) 32.5 31.0 30.5 30.0 70 60 50 40 29.5 30 29.0 -40 -15 10 35 60 85 2.7 3.1 3.5 Temperature (°C) 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Efficiency vs. Input Voltage Quiescent Current vs. Input Voltage (ILED = 31mAx4; Voltage Sweep Downwards) 6.5 Quiescent Current (mA) 90 Efficiency (%) 80 70 60 50 VF = 2.7V VF = 3.0V VF = 3.3V VF = 3.6V 40 30 2.7 3.1 3.5 3.9 4.3 4.7 5.1 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.0 2.7 5.5 85°C 25°C -40°C 2.5 3.1 3.5 Input Voltage (V) 4.7 5.1 5.5 Frequency vs. Temperature 25 850 VIN = 5.5V VIN = 2.7V 20 840 Frequency (KHz) ShutdownnCurrent (nA) 4.3 Input Voltage (V) Shutdown Current vs. Temperature 15 10 5 830 820 810 800 790 780 770 760 0 -40 -15 10 35 60 85 750 -40 Temperature (°C) 6 3.9 -15 10 35 60 85 Temperature (°C) www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Typical Characteristics VIN = 3.6V, CIN = COUT = C1 = 1μF; TA = 25°C, unless otherwise noted. No Load Operating Current vs. Input Voltage EN Input High Threshold Voltage vs. Input Voltage (2x Mode) 1.2 85°C 25°C -40°C 6.2 6.0 1.0 VEN(H) (V) Operating Current (mA) 6.4 5.8 5.6 0.8 0.6 5.4 85°C 25°C -40°C 0.4 5.2 5.0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 0.2 2.7 5.5 3.1 3.5 Input Voltage (V) 1.0 300 TEN/SET(LAT) (µs) VEN(L) (V) 330 0.8 0.6 85°C 25°C -40°C 0.4 3.5 3.9 4.3 4.7 5.1 5.5 EN/SET Input Latch Timeout vs. Input Voltage 1.2 3.1 4.3 Input Voltage (V) EN Input Low Threshold Voltage vs. Input Voltage 0.2 2.7 3.9 4.7 5.1 270 240 210 85°C 25°C -40°C 180 5.5 150 2.7 Input Voltage (V) 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) EN/SET Input OFF Timeout vs. Input Voltage 400 TEN/SET(OFF) (µs) 350 300 250 85°C 25°C -40°C 200 150 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) 3104.2008.09.1.0 www.analogictech.com 7 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Functional Block Diagram C+ C– OUT D1 Two-Mode CP Control D2 IN VF Monitoring 4 D3 2x D4 1x GND 5 EN/SET S2Cwire Control Functional Description The AAT3104 is a low-cost charge-pump solution designed to drive up to four white LEDs. The charge pump operates from a 2.7V to 5.5V power source and converts it to voltage levels necessary to drive the LEDs. LED current is individually controlled through integrated current sources powered from the output of the charge pump. Low 1x charge-pump output resistance and lowdrop voltage current sources allow the charge pump to remain in 1x mode with an input voltage as low as 3.8V and LED forward voltages of 3.5V. Once in 2x mode, the charge pump monitors the input supply voltage and automatically switches back to 1x mode when there is sufficient input voltage. The AAT3104 requires only three external components: one 1μF ceramic capacitor for the charge pump flying capacitor (CP), one 1μF ceramic input capacitor (CIN), one 8 IREF 5 Bits DAC 1μF ceramic output capacitor (COUT). The four constant current outputs of the AAT3104 (D1 to D4) can drive four individual LEDs with a maximum current of 30mA each. AnalogicTech’s S2Cwire serial interface enables the AAT3104-1/-2 and changes the current source magnitudes through the EN/SET pin. S2Cwire Serial Interface The LED output current of the AAT3104 is controlled by AnalogicTech’s S2Cwire serial interface. Since the LED current is programmable, no PWM or additional control circuitry is needed to control LED brightness. This feature greatly reduces the burden on a microcontroller or system IC to manage LED or display brightness, allowing the user to “set it and forget it.” With its high-speed serial interface (1MHz data rate), the LED current can be changed quickly and easily. Also, the non-pulsating LED www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver current reduces system noise and improves LED reliability. The S2Cwire interface relies on the number of rising edges to the EN/SET pin to set the register. A typical write protocol is a burst of EN/SET rising edges, followed by a pause with EN/SET held high for at least tLAT (500μs). The programmed current is then seen at the current source outputs. When EN/SET is held low for an amount of time longer than tOFF (500μs), the AAT3104 enters into shutdown mode and draws less than 1μA from the input and the internal data register is reset to zero. The AAT3104-1/2’s serial interface reduces the LED current on each rising pulse of the enable input. If the AAT3104 is in shutdown, the first rising edge of the EN/ SET input turns on the LED driver to the maximum current. Successive rising edges decrease the LED current as shown in Table 1 and Figure 2 for the AAT3104-1. For the AAT3104-2, Table 2 and Figure 3 illustrate a 32-step LED current control profile. Data EN Rising Edges D1-D4 Current (mA) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0.5 Data EN Rising Edges D1-D4 Current (mA) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0.5 Table 2: AAT3104-2 LED Current Settings. Table 1: AAT3104-1 LED Current Settings. tLO t HI OFF 1 tOFF 2 3 OFF Figure 1: EN/SET Timing Diagram. 3104.2008.09.1.0 www.analogictech.com 9 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Dx Output Current (mA) Dx Output Current (mA) 30.0 22.5 15.0 7.5 30 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 S C Wire Interface Data Code Figure 2: AAT3104-1 Current Control Profile. Applications Information 5 7 9 11 13 15 17 19 21 23 25 27 29 31 Figure 3: AAT3104-2 Current Control Profile. Shutdown LED Selection The AAT3104 is specifically designed for driving white LEDs. However, the device design will allow the AAT3104 to drive most types of LEDs with forward voltage specifications ranging from 2.2V to 4.7V. LED applications may include mixed arrangements for display backlighting, keypad display, and any other application needing a constant current source generated from a varying input voltage. Since the D1 to D4 constant current sources are matched with negligible supply voltage dependence, the constant current channels will be matched regardless of the specific LED forward voltage (VF) levels. The low dropout current sources in the AAT3104 maximize performance and make it capable of driving LEDs with high forward voltages. Multiple channels can be combined to obtain a higher LED drive current without complication. All unused LED source pins should be connected to GND or left floating. Do not connect to the OUT pin. Device Switching Noise Performance The AAT3104 operates at a fixed frequency of approximately 1MHz to control noise and limit harmonics that can interfere with the RF operation of mobile communication devices. Back-injected noise appearing on the input pin of the charge pump is 20mV peak-to peak, typically ten times less than inductor-based DC/DC boost converter white LED backlight solutions. The AAT3104 soft-start feature prevents noise transient effects associated with inrush currents during start-up of the charge pump circuit. 10 3 S2C Wire Interface Data Code 2 Since the current switches are the only power returns for all loads, there is no leakage current when all source switches are disabled. To enter shutdown operation, the EN/SET input for the AAT3104-1/2 should be strobed low. After tOFF (500μs), AAT3104 will be shut down and typically draws less than 1μA from the input. Registers are reset to 0 in shutdown. Power Efficiency and Device Evaluation The charge pump efficiency discussion in the following sections accounts only for efficiency of the charge pump section itself. Due to the unique circuit architecture and design of the AAT3104, it is very difficult to measure efficiency in terms of a percent value comparing input power over output power. Since the AAT3104 outputs are pure constant current sources and typically drive individual loads, it is difficult to measure the output voltage for a given output to derive an overall output power measurement. For any given application, white LED forward voltage levels can differ, yet the output drive current will be maintained as a constant. This makes quantifying output power a difficult task when taken in the context of comparing to other white LED driver circuit topologies. A better way to quantify total device efficiency is to observe the total input power to the device for a given LED current drive level. The best white LED driver for a given application should be based on trade-offs of size, external component count, reliability, operating range, and total energy usage, not just output power over input power efficiency. The AAT3104 efficiency may be quantified under very specific conditions and is dependent upon the input voltage versus the output voltage across the loads applied www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver to outputs D1 through for a given constant current setting. Depending on the combination of VIN and voltages sensed at the current sources, the device will operate in load switch mode. When any one of the voltages sensed at the current sources nears dropout, the device will operate in 2X charge pump mode. Each of these modes will yield different efficiency values. Refer to the following two sections for explanations for each operational mode. 1X Mode Efficiency The AAT3104 1X mode is operational at all times and functions alone to enhance device power conversion efficiency when VIN is higher than the voltage across the load. When in 1X mode, voltage conversion efficiency is defined as output power divided by input power. An expression for the ideal efficiency (η) in 1X chargepump mode can be expressed as: POUT VF · ILED VF · ILED VF ≈ η= P = V ·I =V ·I VIN IN IN IN IN OUT -or- VF η (%) = V · 100 IN For a charge pump led driver with VF of 3.2V and 4.2V input voltage, the theoretical efficiency is 76%. Due to internal switching losses and IC quiescent current consumption, the actual efficiency can be measured at 73%. 2X Charge Pump Mode Efficiency The AAT3104 contains a charge pump which will boost the input supply voltage in the event where VIN is less than the voltage required to supply the output. The efficiency (η) can be simply defined as a linear voltage regulator with an effective output voltage that is equal to one and two times the input voltage. Efficiency (η) for an ideal 2X charge pump can typically be expressed as the output power divided by the input power. η= PF PIN In addition, with an ideal 2X charge pump, the output current may be expressed as 1/3 of the input current. The expression to define the ideal efficiency (η) can be rewritten as POUT VF · ILED VF · ILED VF η= P = V ·I =V ·2·I ≈2·V IN IN IN IN OUT IN 3104.2008.09.1.0 -or- VF η (%) = 2 · V · 100 IN For a charge pump current source driver with VF of 3.2V and 2.7V input voltage, the theoretical efficiency is 59%. Due to internal switching losses and IC quiescent current consumption, the actual efficiency can be measured at 57%. Efficiency will decrease substantially as load current drops below 1mA or when the voltage level at VIN approaches the voltage level at VOUT. Additional Applications The current sources of the AAT3104 can be combined freely to drive higher current levels through one LED. As an example, a single LED can be driven at 120mA by combining together D1 through D4 outputs. For lower-cost applications, the flying capacitor can be removed; C+ and C- should be floating. This will force AAT3104 to operate in 1X mode. To maintain regulated LED current, the input supply voltage has to be higher than the charge-pump's dropout voltage in 1X mode plus the forward voltage of the LED at the preset LED current. Capacitor Selection Careful selection of the three external capacitors CIN, CP, and COUT is important because they will affect turn-on time, output ripple, and transient performance. Optimum performance will be obtained when low equivalent series resistance (ESR) ceramic capacitors are used, in general, low ESR may be defined as less than 100mΩ. A value of 1μF for all four capacitors is a good starting point when choosing capacitors. If the constant current sources are only programmed for light current levels, then the capacitor size may be decreased. Capacitor Characteristics Ceramic composition capacitors are highly recommended over all other types of capacitors for use with the AAT3104. 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 maximizing charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage. www.analogictech.com 11 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Input Voltage 2.7V to 5.5V IN OUT C OUT 1µF C+ C IN 1µF AAT3104 CP 1µF D1 D2 C- D3 EN/SET S2Cwire Interface D4 EN/SET GND Figure 4: Higher Current, Single LED Application. Input Voltage > VF + VDROP IN OUT C OUT 1µF C+ C IN 1µF AAT3104 D1 D2 CEN/SET S2Cwire Interface D3 D4 EN/SET GND Figure 5: Lower Cost 1X Mode Application. Equivalent Series Resistance ESR is an important characteristic to consider when selecting a capacitor. ESR is a resistance internal to a capacitor that 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. Evaluation Board Layout When designing a PCB for the AAT3104, the key requirements are: Ceramic Capacitor Materials Ceramic capacitors less than 0.1μF are typically made from NPO or C0G materials. NPO and C0G materials generally have tight tolerance and are very stable over temperature. Larger capacitor values are usually composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors (i.e., larger than 2.2μF) are often available in low cost Y5V and Z5U dielectrics, but capac- 12 itors larger than 1μF are not typically required for AAT3104 applications. Capacitor area is another contributor to ESR. Capacitors that are physically large will have a lower ESR when compared to an equivalent material smaller capacitor. These larger devices can improve circuit transient response when compared to an equal value capacitor in a smaller package size. 1. 2. Place two flying capacitors C1 and C2 as close to the chip as possible; otherwise 2x mode performance will be compromised. Place input and output decoupling capacitors as close to the chip as possible to reduce switching noise and output ripple. www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Evaluation Board Schematic J1 DC+ DC+ DC- VIN C 10uF 1 2 3 C2 1µF OUT JP1 D4 D3 D2 D1 JP2 JP3 JP4 U1 JP5 1 2 C1 1µF 3 CC+ IN 4 5 D2 D3 D1 D4 OUT VIN CEN/SET C+ GND 10 9 8 7 6 EN AAT3104 C3 1µF EN S2C R2 20K C6 4.7µF U2 PIC12F675 R5 R4 R3 1K 1K 1K S1 S1 UP 1 2 3 4 VDD GP5 GP4 GP3 VSS GP0 GP1 GP2 8 7 6 5 VR1 POT10K C4 0.1µF R7 330 LED2 Red MCU Power R6 330 S2 S2 DOWN LED1 Green S2C S3 S3 CYCLE Figure 6: AAT3104 Evaluation Board Schematic. Figure 6: AAT3104 Evaluation Board Top Layer. 3104.2008.09.1.0 Figure 7: AAT3104 Evaluation Board Bottom Layer. www.analogictech.com 13 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Ordering Information Package Interface Current Control, Inverting Marking1 Part Number (Tape and Reel)2 SC70JW-10 SC70JW-10 S2Cwire S2Cwire 16-step 32-step 4DXYY AAT3104IJQ-1-T1 AAT3104IJQ-2-T1 All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/about/quality.aspx. Package Information SC70JW-10 2.20 ± 0.20 1.75 ± 0.10 0.40 BSC 0.225 ± 0.075 Top View 0.100 7° ± 3° 0.45 ± 0.10 4° ± 4° 0.05 ± 0.05 0.15 ± 0.05 1.10 MAX 0.85 ± 0.15 2.00 ± 0.20 2.10 ± 0.30 Side View End View All dimensions in millimeters. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. 14 www.analogictech.com 3104.2008.09.1.0 PRODUCT DATASHEET AAT3104178 ChargePumpTM Low Cost 1x/2x 4 Channel Charge Pump WLED Driver Advanced Analogic Technologies, Inc. 3230 Scott Boulevard, Santa Clara, CA 95054 Phone (408) 737-4600 Fax (408) 737-4611 © Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Except as provided in AnalogicTech’s terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. 3104.2008.09.1.0 www.analogictech.com 15