AAT1143_06 ANALOGICTECH | Alldatasheet

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Technical content

Features

  • V IN Range: 2.7V to 5.5V
  • V OUT Adjustable Down to 0.6V — Fixed or Adjustable Version
  • 2 5 μA No Load Quiescent Current
  • Up to 95% Efficiency
  • 400mA Max Output Current
  • 1MHz Switching Frequency
  • Soft Start
  • Over-Temperature Protection
  • Current Limit Protection
  • 100% Duty Cycle Low-Dropout Operation
  • 0.1 μA Shutdown Current
  • SC70JW-8 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 (Fixed Output Voltage) Efficiency vs. Load Current (VOUT = 2.5V; VIN = 3.3V) Output Current (mA) Efficiency (%) 100 0.1 1 10 100 1000 4.7μH 4.7μF 4.7μF EN OUT VIN LX AGND PGND PGND PGND AAT1143 VIN VO

(Top View) OUT VIN LX PGND PGND PGND AGND EN 1 Pin # Symbol Function 1 EN Enable pin. 2 OUT Feedback input pin. This pin is connected either directly to the converter output or to an external resistive divider for an adjustable output. 3 VIN Input supply voltage for the converter. 4 LX Switching node. Connect the inductor to this pin. It is internally connected to the drain of both high- and low-side MOSFETs. 5 AGND Non-power signal ground pin. 6, 7, 8 PGND Main power ground return pin. Connect to the output and input capacitor return. AAT1143 1MHz 400mA Step-Down Converter 2 1143.2006.07.1.10

Symbol Description Value Units PD Maximum Power Dissipation (SC70JW-8) 625 mW θJA Thermal Resistance2 (SC70JW-8) 160 °C/W Symbol Description Value Units VIN Input Voltage GND 6.0 V VLX LX to GND -0.3 to V P + 0.3 V VOUT OUT to GND -0.3 to V P + 0.3 V VEN EN to GND -0.3 to 6.0 V TJ Operating Junction Temperature Range -40 to 150 °C TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300 °C AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 3 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi- tions 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.

Electrical Characteristics1 TA = -40°C to +85°C, unless otherwise noted. Typical values are T A = 25°C, VIN = 3.6V. Symbol Description Conditions Min Typ Max Units Step-Down Converter VIN Input Voltage 2.7 5.5 V VIN Rising 2.6 V VUVLO UVLO Threshold Hysteresis 100 mV VIN Falling 1.8 V VOUT Output Voltage Tolerance IOUT = 0 to 400mA, -3.0 +3.0 %VIN = 2.7V to 5.5V VOUT Output Voltage Range Fixed Output Version 0.6 4.0 VAdjustable Output Version2 0.6 2.5 IQ Quiescent Current No Load, 0.6V Adjustable 25 50 μAVersion ISHDN Shutdown Current EN = AGND = PGND 1.0 μA ILIM P-Channel Current Limit 600 mA RDS(ON)H High Side Switch On Resistance 0.45 Ω RDS(ON)L Low Side Switch On Resistance 0.40 Ω ILXLEAK LX Leakage Current VIN = 5.5V, VLX = 0 to VIN, 1 μAEN = GND ΔVLinereg Line Regulation V IN = 2.7V to 5.5V 0.2 %/V VOUT Out Threshold Voltage Accuracy 0.6V Output, No Load 597 600 615 mVTA = 25°C IOUT Out Leakage Current 0.6V Output 0.2 μA ROUT Out Impedance >0.6V Output 250 k Ω FOSC Oscillator Frequency T A = 25°C 0.7 1.0 1.5 MHz TSD Over-Temperature Shutdown Threshold 140 °C THYS Over-Temperature Shutdown Hysteresis 15 °C EN VEN(L) Enable Threshold Low 0.6 V VEN(H) Enable Threshold High 1.4 V IEN Input Low Current V IN = VFB = 5.5V -1.0 1.0 μA AAT1143 1MHz 400mA Step-Down Converter 4 1143.2006.07.1.10 1. The AAT1143 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assu red by design, characterization, and correlation with statistical process controls. 2. For adjustable version with higher than 2.5V output, please consult your AnalogicTech representative.

1MHz 400mA Step-Down Converter 1143.2006.07.1.10 5 Typical Characteristics Output Voltage Error vs. Temperature (VIN = 3.6V; VO = 1.5V) Temperature (°°C) Output Error (%) -2.0 -1.0 0.01.02.0 -40 -20 0 20 40 60 80 100 Frequency vs. Input Voltage (VOUT = 1.8V) Input Voltage (V) Frequency Variation (%) -2.0 -1.5 -1.0 -0.5 0.00.5 1.0 DC Regulation (VOUT = 1.8V; L = 4.7μμH) Output Current (mA) Output Error (%) -2.0 -1.0 0.0 1.02.0 0.1 1 10 100 1000 VIN = 2.7V VIN = 3.6V VIN = 4.2V Efficiency vs. Load (VOUT = 1.8V; L = 4.7μμH) Output Current (mA) Efficiency (%) 100 0.1 1 10 100 1000 VIN = 2.7V VIN = 3.6V VIN = 4.2V Load Regulation (VOUT = 2.5V; L = 4.7μμH) Output Current (mA) Output Error (%) -2.0 -1.0 0.0 1.0 2.0 0.1 1 10 100 1000 VIN = 3.0V VIN = 3.3V VIN = 3.6V Efficiency vs. Load (VOUT = 2.5V; L = 4.7μμH) Output Current (mA) Efficiency (%) 100 0.1 1 10 100 1000 VIN = 3.3V VIN = 3.6V VIN = 3.0V

(30mA to 300mA; VIN = 3.6V; VOUT = 1.8V; C1 = 10μμF; C4 = 100pF; see Figure 1) Output Voltage (AC Coupled) (top) (V) Load and Inductor Current (200mA/div) (bottom) Time (25μs/div) -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.1 0.0 1.2 1.4 0.8 0.6 1.0 0.2 0.4 -0.2 0.0 300mA 30mA N-Channel RDS(ON) vs. Input Voltage Input Voltage (V) RDS(ON) (mΩΩ) 300 350400 450 500 550600 650 700750 25°C 120°C 100°C 85°C Load Transient Response (30mA to 300mA; VIN = 3.6V; VOUT = 1.8V; C1 = 10μμF) Output Voltage (top) (V) Load and Inductor Current (200mA/div) (bottom) Time (25μs/div) 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -0.2 300mA 30mA P-Channel RDS(ON) vs. Input Voltage Input Voltage (V) RDS(ON) (mΩΩ) 300 350 400 450 500 550 600 650 700750 25°C 120°C 100°C 85°C Quiescent Current vs. Input Voltage (VO = 1.8V) Input Voltage (V) Supply Current (μμA) 85°C 25°C -40°C Switching Frequency vs. Temperature (VIN = 3.6V; VO = 1.5V) Temperature (°°C) Variation (%) -0.20 -0.10 0.00 0.100.20 -40 -20 0 20 40 60 80 100 AAT1143 1MHz 400mA Step-Down Converter 6 1143.2006.07.1.10

(VIN = 3.6V; VOUT = 1.8V; 400mA) Output Voltage (AC Coupled) (top) (mV) Inductor Current (bottom) (A) Time (250ns/div) -120 -100 -80 -60 -40 -20 2040 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.80.9 Soft Start (VIN = 3.6V; VOUT = 1.8V; 400mA) Enable and Output Voltage (top) (V) Inductor Current (bottom) (A) Time (250μμs/div) -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Line Regulation (VOUT = 1.8V) Input Voltage (V) Accuracy (%) -0.35 -0.3 -0.25 -0.2 -0.15 -0.1 -0.05 0.05 0.1 IOUT = 400mA IOUT = 100mA IOUT = 10mA Line Transient (VOUT = 1.8V @ 400mA) Output Voltage (top) (V) Input Voltage (bottom) (V) Time (25μμs/div) 1.50 1.55 1.601.65 1.70 1.751.801.851.90 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Load Transient Response (30mA to 300mA; VIN = 3.6V; VOUT = 1.8V; C1 = 4.7μμF) Output Voltage (top) (V) Load and Inductor Current (200mA/div) (bottom) Time (25μs/div) 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -0.2 300mA 30mA AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 7

.Amp Logic DH DL PGND VINOUT AGND Voltage Reference INPUT See note Note: For adjustable version, the internal feedback divider is omitted and the FB pin is tied directly to the internal error amplifier. AAT1143 1MHz 400mA Step-Down Converter 8 1143.2006.07.1.10 Functional Description The AAT1143 is a high performance 400mA 1MHz monolithic step-down converter. It has been designed with the goal of minimizing external com- ponent size and optimizing efficiency over the com- plete load range. Apart from the small bypass input capacitor, only a small L-C filter is required at the output. Typically, a 4.7 μH inductor and a 4.7 μF ceramic capacitor are recommended (see table of values). The fixed output version requires only three external power components (C IN, C OUT, and L). The adjustable version can be programmed with external feedback to any voltage, ranging from 0.6V to the input voltage. An additional feed-forward capacitor can also be added to the external feedback to pro- vide improved transient response (see Figure 1). At dropout, the converter duty cycle increases to 100% and the output voltage tracks the input volt- age minus the R DSON drop of the P-channel high- side MOSFET. The input voltage range is 2.7V to 5.5V. The con- verter efficiency has been optimized for all load conditions, ranging from no load to 400mA. The internal error amplifier and compensation pro- vides excellent transient response, load, and line regulation. Soft start eliminates any output voltage overshoot when the enable or the input voltage is applied.

The AAT1143 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 pro- tection. 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 compen- sation terminates the transconductance voltage error amplifier output. For fixed voltage versions, the error amplifier reference voltage is internally set to program the converter output voltage. 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 AAT1143 into a low-power, non-switching state. The total input current during shutdown is less than 1 μA. Current Limit and Over-Temperature Protection 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. Under-Voltage Lockout Internal bias of all circuits is controlled via the V IN input. Under-voltage lockout (UVLO) guarantees sufficient V IN bias and proper operation of all inter- nal circuitry prior to activation. AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 9 Figure 1: Enhanced Transient Response Schematic. L1 CDRH3D16-4R7 4.7μH 10μF 4.7μF U1 AAT1143 SC70JW-8 C2 4.7μF 10V 0805 X5R VOUT =1.8V GND VIN Enable LX EN OUT VIN LX AGND PGND PGND PGND AAT1143 GND2 118k 59k C1 10μF 6.3V 0805 X5R 100pF

1MHz 400mA Step-Down Converter 10 1143.2006.07.1.10 Applications Information 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 induc- tor value must be selected so the inductor current down slope meets the internal slope compensation requirements. The internal slope compensation for the adjustable and low-voltage fixed versions of the AAT1143 is 0.24A/ μsec. This equates to a slope compensation that is 75% of the inductor current down slope for a 1.5V output and 4.7μH inductor. This is the internal slope compensation for the adjustable (0.6V) version or low-voltage fixed ver- sions. When externally programming the 0.6V ver- sion to 2.5V, the calculated inductance is 7.5μH. In this case, a standard 10μH value is selected. For high-voltage fixed versions (2.5V and above), m = 0.48A/ μsec. Table 1 displays inductor values for the AAT1143 fixed and adjustable options. 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 loss- es 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 4.7 μH CDRH3D16 series inductor selected from Sumida has a 105mΩ DCR and a 900mA DC current rating. At full load, the inductor DC loss is 17mW which gives a 2.8% loss in efficiency for a 400mA, 1.5V output. Input Capacitor Select a 4.7μF to 10μF X7R or X5R ceramic capac- itor for the input. To estimate the required input capacitor size, determine the acceptable input rip- ple level (V PP) and solve for C. The calculated value varies with input voltage and is a maximum when V IN is double the output voltage. Always examine the ceramic capacitor DC voltage coefficient characteristics when selecting the prop- er value. For example, the capacitance of a 10 μF, 6.3V, X5R ceramic capacitor with 5.0V DC applied is actually about 6μF. CIN(MIN) = 1 VPP IO VO VIN VO VIN VO VIN CIN = VO VIN VPP IO 0.75 ⋅ VO L = = ≈ 3 ⋅ VO = 3 ⋅ 2.5V = 7.5μH m 0.75 ⋅ VO 0.24A μsec A μsec A A μsec 0.75 ⋅ VO m = = = 0.24 L 0.75 ⋅ 1.5V 4.7μH A μsec Table 1: Inductor Values. Configuration Output Voltage Inductor Slope Compensation External Resistive Divider 2.5V 10 μH 0.24A/ μsec Fixed Output 0.6V to 2.0V 4.7 μH 0.24A/ μsec 2.5V to 3.3V 4.7 μH 0.48A/ μsec

The maximum input capacitor RMS current is: 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. for V IN = 2 · VO The term appears in both the input voltage ripple and input capacitor RMS current equations and is a maximum when V O is twice VIN. This is why the input voltage ripple and the input capacitor RMS current ripple are a maximum at 50% duty cycle. The input capacitor provides a low impedance loop for the edges of pulsed current drawn by the AAT1143. 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 2. 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 induc- tance of these wires, along with the low-ESR ceramic input capacitor, can create a high Q net- work 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 meas- urements 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 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. 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 typi- cally provides sufficient bulk capacitance to stabi- lize 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 out- put capacitor. During a step increase in load cur- rent, 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 volt- age droop during the three switching cycles to the output capacitance can be estimated by: 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 4.7 μF. 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. COUT = 3 · ΔILOAD VDROOP · FS VO VIN VO VIN IO RMS(MAX)I 2= VO VIN VO VIN VO VIN VO VIN AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 11

For the condition where the step-down converter is in dropout at 100% duty cycle, the total device dis- sipation reduces to: Since R DS(ON), quiescent current, and switching losses all vary with input voltage, the total losses should be investigated over the complete input voltage range. Given the total losses, the maximum junction tem- perature can be derived from the θ JA for the SC70JW-8 package which is 160°C/W. For the condition where the buck converter is in dropout at 100% duty cycle, the total device dissi- pation reduces to: Since R DS(ON), quiescent current, and switching losses all vary with input voltage, the total losses should be investigated over the complete input voltage range. Given the total losses, the maximum junction tem- perature can be derived from the θ JA for the SC70JW-8 package which is 160°C/W. Layout The suggested PCB layout for the AAT1143 is shown in Figures 2, 3, and 4. The following guide- lines should be used to help ensure a proper layout. 1. The input capacitor (C2) should connect as closely as possible to VIN (Pin 3) and PGND (Pins 6 through 8). 2. C1 and L1 should be connected as closely as possible. The connection of L1 to the LX pin should be as short as possible. 3. The feedback trace or OUT pin (Pin 2) should be separate from any power trace and connect as closely as possible to the load point. Sensing along a high-current load trace will degrade DC load regulation. If external feed- back resistors are used, they should be placed as closely as possible to the OUT pin (Pin 2) to minimize the length of the high impedance feedback trace. 4. The resistance of the trace from the load return to PGND (Pins 6 through 8) should be kept to a minimum. This will help to minimize any error in DC regulation due to differences in the poten- tial of the internal signal ground and the power ground. TJ(MAX) = PTOTAL · ΘJA + TAMB PTOTAL = IO 2 · RDS(ON)H + IQ · VIN PTOTAL = IO 2 · RDS(ON)H + IQ · VIN AAT1143 1MHz 400mA Step-Down Converter 14 1143.2006.07.1.10

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 = 1.0MHz TAMB = 85°C 1.8V Output Inductor (see Table 1) For Sumida inductor CDRH3D16, 4.7μH, DCR = 105mΩ. 1.8V Output Capacitor VDROOP = 0.2V 4.7μH · 1.0MHz · 4.2V 23 RMSI L1 · FS · VIN(MAX) = · 3 · ΔILOAD VDROOP · FS 3 · 0.3A 0.2V · 1MHz COUT = = = 4.5 μF

  • = 63mArms (VO) · (VIN(MAX) - VO) = Pesr = esr · IRMS 2 = 5mΩ · (63mA)2 = 20μW IPKL1 = IO + ΔIL1 PL1 = IO 2 ⋅ DCR = 0.4A2 ⋅ 105mΩ = 17mW L1 = 3 ⋅ VO2 = 3 ⋅ 1.8V = 5.4μHμsec A μsec A AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 15

1MHz 400mA Step-Down Converter 16 1143.2006.07.1.10 Input Capacitor Input Ripple VPP = 25mV AAT1143 Losses TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (160°C/W) · 122mW = 104.5°C PTOTAL + (tsw · FS · IO + IQ) · VIN IO 2 · (RDS(ON)H · VO + RDS(ON)L · [VIN -VO]) VIN + (5ns · 1.0MHz · 0.4A + 50μA) · 4.2V = 122mW 4.2V IO RMSI P = esr · IRMS 2= = 0.2Arms CIN = = = 4.75 μF1 VPP IO 25mV 0.4A

Table 3: Evaluation Board Component Values. Table 4: Typical Surface Mount Inductors. Inductance Max DC DCR Size (mm) Manufacturer Part Number ( μH) Current (A) ( ΩΩ) LxWxH Type VOUT (V) R1 (k ΩΩ) R1 (k ΩΩ) L1 ( μH) Adjustable Version R2 = 59kΩΩ R2 = 221kΩΩ11 (0.6V device) 0.8 19.6 75.0 4.7 0.9 29.4 113 4.7 1.0 39.2 150 4.7 1.1 49.9 187 4.7 1.2 59.0 221 4.7 1.3 68.1 261 4.7 1.4 78.7 301 4.7 1.5 88.7 332 4.7 1.8 118 442 4.7 1.85 124 464 4.7 2.0 137 523 4.7 or 6.8 2.5 187 715 10 VOUT (V) R1 (k ΩΩ) L1 ( μH) Fixed Version R2 Not Used 0.6-3.3V 0 4.7 AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 17 1. For reduced quiescent current R2 = 221k Ω.

Table 5: Surface Mount Capacitors. Manufacturer Part Number Value Voltage Temp. Co. Case MuRata GRM21BR61A475KA73L 4.7 μF 10V X5R 0805 MuRata GRM18BR60J475KE19D 4.7 μF 6.3V X5R 0603 MuRata GRM21BR60J106KE19 10 μF 6.3V X5R 0805 MuRata GRM21BR60J226ME39 22 μF 6.3V X5R 0805 AAT1143 1MHz 400mA Step-Down Converter 18 1143.2006.07.1.10

Ordering Information

Package Information

All dimensions in millimeters. 0.225 ± 0.075 0.45 ± 0.10 0.05 ± 0.05 2.10 ± 0.30 2.00 ± 0.20 7° ± 3° 4° ± 4° 0.15 ± 0.05

1.10 MAX

0.100 2.20 ± 0.20 0.048REF 0.50 BSC 0.50 BSC 0.50 BSC All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means Output Voltage1 Package Marking 2 Part Number (Tape and Reel)3 0.6 SC70JW-8 NUXYY AAT1143IJS-0.6-T1 1.2 SC70JW-8 PBXYY AAT1143IJS-1.2-T1 1.5 SC70JW-8 NXXYY AAT1143IJS-1.5-T1 1.6 SC70JW-8 PYXYY AAT1143IJS-1.6-T1 1.8 SC70JW-8 OKXYY AAT1143IJS-1.8-T1 2.5 SC70JW-8 OYXYY AAT1143IJS-2.5-T1 3.3 SC70JW-8 PLXYY AAT1143IJS-3.3-T1 AAT1143 1MHz 400mA Step-Down Converter 1143.2006.07.1.10 19 1. Contact Sales for other voltage options. 2. XYY = assembly and date code. 3. Sample stock is generally held on part numbers listed in BOLD.

1MHz 400mA Step-Down Converter 20 1143.2006.07.1.10 Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 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. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold sub- ject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality con- trol 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 produ ct names appearing in this document are regis- tered trademarks or trademarks of their respective holders.