AAT1151 AAT, AAT1151 Datasheet
AAT1151
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AAT1151 Summary of contents
Page 1
... The device operates at a fixed 850kHz switching fre- quency and enters PFM mode for light load current to maintain high efficiency across all load conditions. The AAT1151 is available in MSOP-8 and QFN33-16 packages and is rated over the -40°C to +85°C tem- perature range. ...
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... Enable input pin. A logic high enables the converter; a logic low forces the AAT1151 into shutdown mode reducing the supply current to less than 1µA. The pin should not be left floating. Bias supply. Supplies power for the internal circuitry. Connect to input power via low pass filter with decoupling to SGND ...
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... Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. 3. Mounted on a demo board. 4. Derate 6.7mW/°C above 25°C. 5. Derate 20mW/°C above 25°C. 1151.2005.11.1.4 850kHz 700mA Synchronous Buck DC/DC Converter 1 - HBM 3 = 25° 25°C) A AAT1151 Value 6 -0 +0 +0 -40 to 150 3000 Value ...
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... Enable Threshold High EN(H) T Over-Temperature Shutdown SD Threshold T Over-Temperature Shutdown HYS Hysteresis 1. The AAT1151 is guaranteed to meet performance specifications over the -40°C to +85°C operating range and is assured by design, characterization, and correlation with statistical process controls. 4 850kHz 700mA Synchronous Buck DC/DC Converter 1 Conditions 0.2 to 5.5V, IN ...
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... AAT1151 Frequency vs. Input Voltage 3 3.5 4 4.5 5 Input Voltage (V) Load and Line Regulation 100 Load Current (mA) AAT1151 Efficiency = 2.5V 4.2µ µ OUT 10 100 1000 Output Current (mA) 5.5 1000 10000 5 ...
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... Soft Start 1.8V, 0.7A -0.5 -4 AAT1151 Circuit of Figure 1 120 100 -20 -40 Time (20µ µ s/div) Circuit of Figure 1 120 100 -20 -40 Time (20µ µ s/div) = 3.6V IN Circuit of Figure 1 3.5 3 2.5 2 1.5 1 0.5 0 -0.5 Time (200µ µ s/div) ...
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... Typical Characteristics Output Ripple Circuit of Figure 2. 4. Output Current (mA) 1151.2005.11.1.4 850kHz 700mA Synchronous Buck DC/DC Converter V = 3.6V IN 100 1000 AAT1151 7 ...
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... FB SGND Operation Control Loop The AAT1151 is a peak current mode buck con- verter. The inner, wide bandwidth loop controls the peak current of the output inductor. The output inductor current is sensed through the P-channel MOSFET (high side) and is also used for short-cir- cuit and overload protection ...
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... During overload and tran- sient conditions, the average current in the inductor can meet or exceed the current limit point of the AAT1151. These conditions can tolerate greater sat- uration in the inductor without degradation in con- verter performance. Some inductors may meet the 1151 ...
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... Input Capacitor The primary function of the input capacitor is to pro- vide a low impedance loop for the edges of pulsed current drawn by the AAT1151. A low ESR/ESL ceramic capacitor is ideal for this function. To mini- mize stray inductance, the capacitor should be placed as close as possible to the IC. This keeps the ...
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... Output Voltage (V) Figure 6: R3 vs. V for Adjustable Output OUT Using the AAT1151-1.0V. 1151.2005.11.1.4 850kHz 700mA Synchronous Buck DC/DC Converter Figure 3: MSOP Evaluation Figure 5: QFN Evaluation Board 2.7V-5.5V R1 100 R2 100k C1 C3 10µF 0.1 µF C1 Murata 10µF 6.3V X5R GRM42-6X5R106K6.3 C2, C4 MuRata 22µF 6.3V GRM21BR60J226ME39L X5R 0805 ...
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... Thermal Calculations There are two types of losses associated with the AAT1151 output switching MOSFET: switching loss- es and conduction losses. Conduction losses are associated with the R characteristics of the DS(ON) output switching device. At the full load condition, assuming continuous conduction mode (CCM), a simplified form of the total losses is given by: ...
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... Pesr = esr · 5mΩ · 50µW RMS 1151.2005.11.1.4 850kHz 700mA Synchronous Buck DC/DC Converter × ⎛ ⎞ 1.5V ⋅ 4.05µH ⎝ ⎠ 4.2V ⎛ ⎞ 1.5V ⋅ 340mA ⎝ ⎠ 4.2V 1 1.5V · (4.2V - 1.5V) · = 99mArms 3.3µH · 850kHz · 4.2V 2 · 3 AAT1151 13 ...
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... AAT1151 Dissipation · (R · DSON(H) O DSON( TOTAL (0.7A) · (0.2Ω · 1.5V + 0.187Ω · (4.2V - 1.5V)) = 4.2V + Θ · 85°C + 150°C/W · 0.145W = 107°C (MSOP-8) J(MAX) AMB JA LOSS = 85°C + 50°C/W · 0.145W = 92°C (QFN33-16) Surface Mount Inductors Manufacturer ...
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... JHXYY JHXYY MSOP-8 JIXYY JIXYY MSOP-8 JJXYY JJXYY MSOP-8 NKXYY MSOP-8 1.95 BSC 0.254 BSC 3.00 ± 0.10 10° ± 5° 0.30 ± 0.08 0.65 BSC AAT1151 Part Number (Tape and Reel) AAT1151IKS-1.0-T1 AAT1151IVN-1.0-T1 AAT1151IKS-1.8-T1 AAT1151IVN-1.8-T1 AAT1151IKS-2.5-T1 AAT1151IVN-2.5-T1 AAT1151IKS-3.3-T1 4° ± 4° 0.60 ± 0.20 0.155 ± 0.075 3 15 ...
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... AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 16 850kHz 700mA Synchronous Buck DC/DC Converter QFN33-16 0.230 ± 0.05 Pin 1 Identification 0.500 ± 0.05 Bottom View 0.203 ± 0.0254 Side View AAT1151 5 1151.2005.11.1.4 ...