PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter General Description Features The AAT1149B SwitchReg is a 2.2MHz step-down converter with an input voltage range of 2.2V to 5.5V. It is optimized to react quickly to load variations and operate with a tiny 0603 inductor that is only 1mm tall. • • • • • • • • • • • • • • • The AAT1149B can deliver 400mA of load current while maintaining a low 45μA no load quiescent current. The 2.2MHz switching frequency minimizes the size of external components while keeping switching losses low. The AAT1149B maintains high efficiency throughout the operating range, which is critical for portable applications. The AAT1149B is available in a Pb-free, space-saving 5-pin wafer-level chip scale (WLCSP) package and is rated over the -40°C to +85°C temperature range. Ultra-Small 0603 Inductor (Height = 1mm) VIN Range: 2.2V to 5.5V VOUT Fixed 1.8V 400mA Max Output Current Up to 98% Efficiency 45μA No Load Quiescent Current 2.2MHz Switching Frequency 70μs Soft Start Fast Load Transient Over-Temperature Protection Current Limit Protection 100% Duty Cycle Low-Dropout Operation <1μA Shutdown Current 0.9x1.2mm WLCSP Package Temperature Range: -40°C to +85°C Applications • • • • • • Cellular Phones Digital Cameras Handheld Instruments Microprocessor / DSP Core / IO Power PDAs and Handheld Computers USB Devices Typical Application VIN = 3.6V C2 4.7µF 1149B.2008.07.1.0 U1 AAT1149B IN LX EN FB AGND PGND PGND PGND www.analogictech.com VOUT = 1.8V L1 2.2µH C1 4.7µF 1 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Pin Descriptions Pin # Symbol 1 2 4 FB EN AGND PGND IN 5 LX 3 Function Feedback input pin. Connect this pin ito the converted output voltage node. Enable pin. Non-power signal ground pin. Main power ground return pins. Connect to the output and input capacitor return. Input supply voltage for the converter. Switching node. Connect the inductor to this pin. It is internally connected to the drain of both high- and low-side MOSFETs. Pin Configuration WLCSP-5 (Top View) FB AGND/PGND IN 2 1 2 EN 5 LX 3 4 www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Absolute Maximum Ratings1 Symbol VIN VLX VFB VEN TJ TLEAD Description Input Voltage to GND LX to GND FB to GND EN to GND Operating Junction Temperature Range Maximum Soldering Temperature (at leads, 10 sec) Value Units 6.0 -0.3 to VIN + 0.3 -0.3 to VIN + 0.3 -0.3 to 6.0 -40 to 150 300 V V V V °C °C Value Units 352 284 mW °C/W Thermal Information Symbol PD θJA Description Maximum Power Dissipation Thermal Resistance2 2, 3 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 board; use the NSMD (none-solder mask defined) pad style for tighter control on the copper etch process. 3. Derate 3.52 mW/°C above 25°C. 1149B.2008.07.1.0 www.analogictech.com 3 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Electrical Characteristics1 VIN = 3.6V, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Conditions Step-Down Converter Input Voltage VIN VOUT Output Voltage Tolerance Quiescent Current IQ ISHDN Shutdown Current P-Channel Current Limit ILIM High Side Switch On Resistance RDS(ON)H RDS(ON)L Low Side Switch On Resistance LX Leakage Current ILXLEAK Line Regulation ΔVLinereg TS Start-Up Time FOSC Oscillator Frequency TSD Over-Temperature Shutdown Threshold THYS Over-Temperature Shutdown Hysteresis EN Enable Threshold Low VEN(L) VEN(H) Enable Threshold High IEN Input Low Current IOUT = 0 to 400mA, VIN = 2.7V to 5.5V No Load VEN = GND Min Typ 2.2 -3.0 45 Max Units 5.5 3.0 70 1.0 V % mA μA mA Ω Ω μA %/V μs MHz °C °C 600 0.40 0.35 VIN = 5.5V, VLX = 0 to VIN, VEN = GND VIN = 2.7V to 5.5V From Enable to Output Regulation TA = 25°C 1 0.1 70 2.2 140 15 0.6 VIN = VOUT = 5.5V 1.4 -1.0 1.0 V V μA 1. The AAT1149B 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 www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Typical Characteristics Efficiency vs. Output Current Load Regulation (VOUT = 1.8V; L = 1.5µH) (VOUT = 1.8V; L = 1.5µH) 100 2 90 1.5 Output Error (%) Efficiency (%) 80 70 60 VIN = 5.5V VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 3V VIN = 2.7V VIN = 2.3V 50 40 30 20 10 0 0.1 1 10 100 VIN = 5.5V VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 3V VIN = 2.7V VIN = 2.3V 1 0.5 0 -0.5 -1 -1.5 -2 1000 0.1 10 1 Output Current (mA) 100 1000 10000 Output Current (A) No Load Quiescent Current vs. Input Voltage Frequency Variation vs. Input Voltage (VOUT = 1.8V) 2 Frequency Variation (%) Supply Current (µA) 5 4.5 4 3.5 3 2.5 2 T = 85°C T = 25°C T = -40°C 1.5 1 2.5 3 3.5 4 4.5 5 5.5 6 1 0 -1 -2 -3 -4 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Input Voltage (V) Switching Frequency Variation vs. Temperature Output Voltage Error vs. Temperature (VIN = 3.6V; VO = 1.8V; IOUT = 400mA) 2.0 10 8 Output Error (%) Variation (%) 6 4 2 0 -2 -4 -6 1.0 0.0 -1.0 -8 -10 -40 -20 0 20 40 60 80 100 120 -2.0 -40 Temperature (°°C) 1149B.2008.07.1.0 -20 0 20 40 60 80 100 Temperature (°°C) www.analogictech.com 5 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Typical Characteristics Line Regulation Line Transient (VOUT = 1.8V) (VOUT = 1.8V; VIN = 3.6V to 4.2V) Accuracy (%) 0.6 400mA 0.4 0mA 0.2 100mA 0 -0.2 -0.4 600mA -0.6 -0.8 -1 2.5 3 3.5 4 4.5 5 5.5 5 4 3 2 1 0.04 0 0.02 0 -0.02 6 Input Voltage (V) Time (200µs/div) N-Channel RDS(ON) vs. Input Voltage Line Transient (WLCSP-5) 1.94 4.25 1.92 4.00 1.90 3.75 1.88 3.50 1.86 3.25 1.84 3.00 1.82 2.75 1.80 2.50 1.78 750 700 650 RDS(ON) (mΩ Ω) 4.50 Output Voltage (bottom) (V) Input Voltage (top) (V) (VOUT = 1.8V; No Load) 550 500 450 85°C 400 350 25°C 300 250 2.5 3 Output Voltage (AC Coupled) (bottom) (V) RDS(ON) (mΩ Ω) 100°C 600 550 85°C 400 25°C 300 250 2.5 3 3.5 4 4.5 5 5.5 5.5 6 0.6 400mA 0.4 0.2 40mA 0.0 2.2 2.0 1.8 1.6 1.4 6 Input Voltage (V) 6 5 Output Current (top) (A) 700 350 4.5 (VIN = 3.6V; VOUT = 1.8V; IOUT = 40mA to 400mA; COUT = 4.7µF) 750 450 4 Step-Down Converter Load Transient Response (WLCSP-5) 500 3.5 Input Voltage (V) P-Channel RDS(ON) vs. Input Voltage 120°C 100°C 120°C 600 Time (50µs/div) 650 Output Voltage (bottom) (20mV/div) Input Voltage (top) (1V/div) 1 0.8 Time (100µs/div) www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Typical Characteristics Soft Start 4.00 2.00 3.00 1.75 2.00 1.50 1.00 1.25 0.00 1.00 -1.00 0.75 -2.00 0.50 -3.00 0.25 -4.00 0.00 Inductor Current (bottom) (250mA/div) Enable and Output Voltage (top) (V) (VOUT = 1.8V) Time (50µs/div) 1149B.2008.07.1.0 www.analogictech.com 7 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Functional Block Diagram IN FB Err Amp . DH Voltage Reference EN LX Logic DL INPUT PGND AGND Functional Description The AAT1149B is a high performance 400mA 2.2MHz monolithic step-down converter. It minimizes external component size, enabling the use of a tiny 0603 inductor that is only 1mm tall, and is optimized for low noise. Apart from the small bypass input capacitor, only a small L-C filter is required at the output. Typically, a 1.8μH inductor and a 4.7μF ceramic capacitor are recommended (see table of values). Only three external power components (CIN, COUT, and L) are required. Output voltage is fixed internally. 8 At dropout, the converter duty cycle increases to 100% and the output voltage tracks the input voltage minus the RDS(ON) drop of the P-channel high-side MOSFET. The input voltage range is 2.2V to 5.5V. The converter efficiency has been optimized for all load conditions, ranging from no load to 400mA. The internal error amplifier and compensation provides excellent transient response, load, and line regulation. Soft start eliminates any output voltage overshoot when the enable or the input voltage is applied. www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Applications Information Control Loop The AAT1149B is a peak current mode step-down converter. The current through the P-channel MOSFET (high side) is sensed for current loop control, as well as short circuit and overload protection. A fixed slope compensation signal is added to the sensed current to maintain stability for duty cycles greater than 50%. The peak current mode loop appears as a voltage-programmed current source in parallel with the output capacitor. The output of the voltage error amplifier programs the current mode loop for the necessary peak switch current to force a constant output voltage for all load and line conditions. Internal loop compensation terminates the transconductance voltage error amplifier output. For the adjustable output, the error amplifier reference is fixed at 0.6V. Soft Start / Enable Soft start limits the current surge seen at the input and eliminates output voltage overshoot. When pulled low, the enable input forces the AAT1149B into a low-power, non-switching state. The total input current during shutdown is less than 1μA. Current Limit and Over-Temperature Protection Inductor Selection The step-down converter uses peak current mode control with slope compensation to maintain stability for duty cycles greater than 50%. The output inductor value must be selected so the inductor current down slope meets the internal slope compensation requirements. A 2.2μH inductor is recommended for a 1.875V output. Manufacturer’s specifications list both the inductor DC current rating, which is a thermal limitation, and the peak current rating, which is determined by the saturation characteristics. The inductor should not show any appreciable saturation under normal load conditions. Some inductors may meet the peak and average current ratings yet result in excessive losses due to a high DCR. Always consider the losses associated with the DCR and its effect on the total converter efficiency when selecting an inductor. The 2.2μH CBC2518 series inductor selected from Taiyo Yuden has a 130mW DCR and a 890mA saturation current rating. At full load, the inductor DC loss is 21mW which gives a 2.8% loss in efficiency for a 400mA, 1.875V output. Input Capacitor For overload conditions, the peak input current is limited. To minimize power dissipation and stresses under current limit and short-circuit conditions, switching is terminated after entering current limit for a series of pulses. Switching is terminated for seven consecutive clock cycles after a current limit has been sensed for a series of four consecutive clock cycles. Thermal protection completely disables switching when internal dissipation becomes excessive. The junction over-temperature threshold is 140°C with 15°C of hysteresis. Once an over-temperature or over-current fault conditions is removed, the output voltage automatically recovers. Select a 4.7μF to 10μF X7R or X5R ceramic capacitor for the input. To estimate the required input capacitor size, determine the acceptable input ripple level (VPP) and solve for C. The calculated value varies with input voltage and is a maximum when VIN is double the output voltage. CIN = V ⎞ VO ⎛ · 1- O VIN ⎝ VIN ⎠ ⎛ VPP ⎞ - ESR · FS ⎝ IO ⎠ VO ⎛ V ⎞ 1 · 1 - O = for VIN = 2 · VO VIN ⎝ VIN ⎠ 4 1 CIN(MIN) = ⎛ VPP ⎞ - ESR · 4 · FS ⎝ IO ⎠ Always examine the ceramic capacitor DC voltage coefficient characteristics when selecting the proper value. For example, the capacitance of a 10μF, 6.3V, X5R ceramic capacitor with 5.0V DC applied is actually about 6μF. 1149B.2008.07.1.0 www.analogictech.com 9 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter The maximum input capacitor RMS current is: IRMS = IO · the converter performance, a high ESR tantalum or aluminum electrolytic should be placed in parallel with the low ESR, ESL bypass ceramic. This dampens the high Q network and stabilizes the system. VO ⎛ V ⎞ · 1- O VIN ⎝ VIN ⎠ The input capacitor RMS ripple current varies with the input and output voltage and will always be less than or equal to half of the total DC load current. VO ⎛ V ⎞ · 1- O = VIN ⎝ VIN ⎠ D · (1 - D) = 0.52 = 1 2 for VIN = 2 · VO IRMS(MAX) = VO IO 2 ⎛ V ⎞ · 1- O The term V ⎝ V ⎠ appears in both the input voltage ripple and input capacitor RMS current equations and is a maximum when VO is twice VIN. This is why the input voltage ripple and the input capacitor RMS current ripple are a maximum at 50% duty cycle. IN IN The input capacitor provides a low impedance loop for the edges of pulsed current drawn by the AAT1149B. Low ESR/ESL X7R and X5R ceramic capacitors are ideal for this function. To minimize stray inductance, the capacitor should be placed as closely as possible to the IC. This keeps the high frequency content of the input current localized, minimizing EMI and input voltage ripple. The proper placement of the input capacitor (C2) can be seen in the evaluation board layout in Figure 1. A laboratory test set-up typically consists of two long wires running from the bench power supply to the evaluation board input voltage pins. The inductance of these wires, along with the low-ESR ceramic input capacitor, can create a high Q network that may affect converter performance. This problem often becomes apparent in the form of excessive ringing in the output voltage during load transients. Errors in the loop phase and gain measurements can also result. Since the inductance of a short PCB trace feeding the input voltage is significantly lower than the power leads from the bench power supply, most applications do not exhibit this problem. In applications where the input power source lead inductance cannot be reduced to a level that does not affect 10 Output Capacitor The output capacitor limits the output ripple and provides holdup during large load transitions. A 4.7μF to 10μF X5R or X7R ceramic capacitor typically provides sufficient bulk capacitance to stabilize the output during large load transitions and has the ESR and ESL characteristics necessary for low output ripple. The output voltage droop due to a load transient is dominated by the capacitance of the ceramic output capacitor. During a step increase in load current, the ceramic output capacitor alone supplies the load current until the loop responds. Within two or three switching cycles, the loop responds and the inductor current increases to match the load current demand. The relationship of the output voltage droop during the three switching cycles to the output capacitance can be estimated by: COUT = 3 · ΔILOAD VDROOP · FS Once the average inductor current increases to the DC load level, the output voltage recovers. The above equation establishes a limit on the minimum value for the output capacitor with respect to load transients. The internal voltage loop compensation also limits the minimum output capacitor value to 4.7μF. This is due to its effect on the loop crossover frequency (bandwidth), phase margin, and gain margin. Increased output capacitance will reduce the crossover frequency with greater phase margin. The maximum output capacitor RMS ripple current is given by: IRMS(MAX) = 1 VOUT · (VIN(MAX) - VOUT) L · FS · VIN(MAX) 2· 3 · Dissipation due to the RMS current in the ceramic output capacitor ESR is typically minimal, resulting in less than a few degrees rise in hot-spot temperature. www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Figure 1: AAT1149BIUV Evaluation Board Top Side. Figure 2: AAT1149BIUV Evaluation Board Bottom Side. VIN U1 4 5 IN AAT1149BIUV EN 2 L1 LX EN FB VOUT C3 open R1 0 1 R2 open C1 4.7μF C2 4.7μF GND 3 WLCSP-5 Figure 3: AAT1149BIUV Evaluation Board Schematic. Thermal Calculations There are three types of losses associated with the AAT1149B step-down converter: switching losses, conduction losses, and quiescent current losses. Conduction losses are associated with the RDS(ON) characteristics of the power output switching devices. Switching losses are dominated by the gate charge of the power output switching devices. At full load, assuming continuous conduction mode (CCM), a simplified form of the losses is given by: 1149B.2008.07.1.0 PTOTAL = IO2 · (RDS(ON)H · VO + RDS(ON)L · [VIN - VO]) VIN + (tsw · FS · IO + IQ) · VIN IQ is the step-down converter quiescent current. The term tsw is used to estimate the full load step-down converter switching losses. www.analogictech.com 11 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter For the condition where the step-down converter is in dropout at 100% duty cycle, the total device dissipation reduces to: PTOTAL = IO2 · RDS(ON)H + IQ · VIN Layout The suggested PCB layout for the AAT1149B is shown in Figures 1 and 2. The following guidelines should be used to help ensure a proper layout. 1. Since RDS(ON), quiescent current, and switching losses all vary with input voltage, the total losses should be investigated over the complete input voltage range. 2. Given the total losses, the maximum junction temperature can be derived from the θJA for the WLCSP-8 package which is 284°C/W. 3. TJ(MAX) = PTOTAL · ΘJA + TAMB 4. WLCSP Package Light Sensitivity The electrical performance of the WLCSP package can be adversely affected by exposing the device to certain light sources such as direct sunlight or a halogen lamp whose wavelengths are red and infra-reds. However, fluorescent lighting has very little effect on the electrical performance of the WLCSP package. 12 5. The input capacitor (C2) should connect as closely as possible to IN (Pin 4) and PGND (Pin 3). C1 and L1 should be connected as closely as possible. The connection of L1 to the LX pin should be as short as possible. The feedback trace or FB pin (Pin 1) should be separate from any power trace and connect as closely as possible to the load point. Sensing along a highcurrent load trace will degrade DC load regulation. The resistance of the trace from the load return to the PGND (Pin 3) should be kept to a minimum. This will help to minimize any error in DC regulation due to differences in the potential of the internal signal ground and the power ground. The pad on the PCB for the WLCSP-5 package should use NSMD (non-solder mask defined) configuration due to its tighter control on the copper etch process. A pad thickness of less than 1oz is recommended to achieve higher stand-off. www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Step-Down Converter Design Example Specifications VO = 1.8V @ 400mA (adjustable using 0.6V version), Pulsed Load ΔILOAD = 300mA VIN = 2.7V to 4.2V (3.6V nominal) FS = 2.2MHz TAMB = 85°C 1.8V Output Inductor L1 = 1 µs µs · VO = 1 · 1.8V = 1.8µH (use 2.2μH) A A For Taiyo Yuden inductor CBC2518T2R2M, 2.2μH, DCR = 130mΩ. ΔIL1 = VO V 1.8V 1.8V · 1- O = · 1= 214mA L1 · FS VIN 2.2µH · 2.2MHz 4.2V IPKL1 = IO + ΔIL1 = 0.4A + 0.107A = 0.507A 2 PL1 = IO2 · DCR = 0.4A2 · 130mΩ = 21mW 1.8V Output Capacitor VDROOP = 0.1V COUT = 3 · ΔILOAD 3 · 0.3A = = 4.1µF; use 4.7µF 0.1V · 2.2MHz VDROOP · FS IRMS = (VO) · (VIN(MAX) - VO) 1 1.8V · (4.2V - 1.8V) · = 62mArms = L1 · FS · VIN(MAX) 2 · 3 2.2µH · 2.2MHz · 4.2V 2· 3 1 · Pesr = esr · IRMS2 = 5mΩ · (62mA)2 = 19µW 1149B.2008.07.1.0 www.analogictech.com 13 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Input Capacitor Input Ripple VPP = 10mV CIN = IRMS = 1 VPP - ESR · 4 · FS IO 1 = 10mV - 5mΩ · 4 · 2.2MHz 0.4A = 5.7µF; use 4.7µF IO = 0.2Arms 2 P = esr · IRMS2 = 5mΩ · (0.2A)2 = 0.2mW AAT1149B Losses (WLCSP-5 Package) PTOTAL = IO2 · (RDS(ON)H · VO + RDS(ON)L · [VIN -VO]) VIN + (tsw · FS · IO + IQ) · VIN = 0.42 · (0.725Ω · 1.8V + 0.7Ω · [4.2V - 1.8V]) 4.2V + (5ns · 2.2MHz · 0.4A + 3mA) · 4.2V = 149mW TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (284°C/W) · 149mW = 127°C 14 www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Part Number/Type Inductance (μH) Rated Current (mA) DCR (mΩ) BRL2012 2.2 550 250 0805 (HMAX = 1mm) CBC2518 Wire Wound Chip 2.2 890 130 2.5x1.8x1.8 Sumida CDRH2D09 Shielded 2.5 440 150 3.2x3.2x1.0 Murata LQM2MPN2R2NGOL Unshielded 2.2 1200 110 2.0x1.6x0.95 Coiltronics SD3118 Shielded 2.2 510 116 3.15x3.15x1.2 Manufacturer Taiyo Yuden Size (mm) LxWxH Table 1: Typical Surface Mount Inductors. Manufacturer Part Number Value Voltage Temp. Co. Case Murata Murata Murata GRM219R61A475KE19 GRM21BR60J106KE19 GRM185R60J475M 4.7μF 10μF 4.7μF 10V 6.3V 6.3V X5R X5R X58 0805 0805 0603 Table 2: Surface Mount Capacitors. 1. For reduced quiescent current, R2 = 221kΩ. 1149B.2008.07.1.0 www.analogictech.com 15 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter Ordering Information Output Voltage1 Package Marking Part Number (Tape and Reel)2 1.875 WLCSP-5 ZZYW AAT1149BIUV-1.8-T1 3 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 WLCSP-5 0.910 ± 0.035 0.400 BSC 0.180 + 0.030 - 0.025 0.300 0.380 Line_1: Part Code Line_2: Year Code + Date Code 0.300 0.070 1.235 ± 0.035 Line_2 0.4 00 BS C 60° 0.693 BSC Line_1 0.140 0.200 ± 0.030 Top View Side View + 0.030 0.580 -0.070 Bottom View ø 0.2 (Ref.) Pin 1 indication End View All dimensions in millimeters. 1. Contact Sales for other voltage options. 3. Sample stock is generally held on part numbers listed in BOLD. 3. YW = date code (year, week) for WLCSP-5 package. 16 www.analogictech.com 1149B.2008.07.1.0 PRODUCT DATASHEET AAT1149B SwitchRegTM 2.2MHz Fast Transient 400mA Step-Down Converter 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. 1149B.2008.07.1.0 www.analogictech.com 17