AAT1120 Advanced Analogic Technologies, Inc., AAT1120 Datasheet

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... The AAT1120 feedback and control delivers excellent load regulation and tran- sient response with a small output inductor and capacitor. The AAT1120 is available in a Pb-free, 8-pin, 2x2mm STDFN package and is rated over the -40°C to +85°C temperature range. Typical Application ...

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... Input power return pin; connected to the source of the N-channel MOSFET. Connect to the output and input capacitor return. EP Exposed paddle (bottom): connect to ground directly beneath the package. Pin Configuration 2 500mA Step-Down Converter STDFN22-8 (Top View) VP PGND 1 8 VIN GND N AAT1120 1120.2007.01.1.0 ...

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... 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. 1120.2007.01.1.0 500mA Step-Down Converter 1 (STDFN22-8) 2 AAT1120 Value Units 6 ...

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... Enable Threshold High EN(H) I Input Low Current EN 1. The AAT1120 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. 2. Output voltage tolerance is independent of feedback resistor network accuracy. 4 500mA Step-Down Converter ...

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... V = 4.2V IN 0.0 -0.5 -1.0 -1.5 -2.0 100 1000 0 0.5 0 -0.5 -1 -1.5 -2 0.1 100 1000 AAT1120 500mA Step-Down Converter Load Regulation (V = 3.0V 4.7µH) OUT 100 Output Current (mA) Load Regulation (V = 1.8V 3.3µH) OUT 100 Output Current (mA) Load Regulation (V = 1.2V 1.5µH) ...

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... Switching Frequency Variation = 500mA) 10.0 8.0 6.0 4.0 2.0 0.0 -2.0 -4.0 -6.0 -8.0 -10 100 -40 No Load Quiescent Current vs. Input Voltage 85°C 35 25° -40° 4.7 5.1 5.5 2.7 AAT1120 Line Regulation (V = 1.8V) OUT I = 50mA OUT I = 10mA OUT I = 250mA I = 0mA OUT OUT I = 150mA OUT 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) vs. Temperature (V = 3.6V 1.8V) IN OUT - ...

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... Step-Down Converter 750 700 650 600 550 500 450 400 350 300 5.0 5.5 6.0 2.5 = 1.8V; (350mA to 500mA; V OUT 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 AAT1120 N-Channel R vs. Input Voltage DS(ON) 120°C 100°C 85°C 25°C 3.0 3.5 4.0 4.5 5.0 Input Voltage (V) Load Transient Response = 3.6V 1.8V; IN OUT C = 4.7µ 100pF) OUT Time (25µs/div) 5.5 6.0 7 ...

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... Typical Characteristics Output Ripple (V = 3.6V 1.8V OUT OUT - Time (2µs/div) 8 500mA Step-Down Converter = 1mA 0.04 -20 0.03 -40 0.02 -60 0.01 -80 0.00 -100 -0.01 -120 AAT1120 Output Ripple (V = 3.6V 1.8V 500mA) IN OUT OUT Time (200ns/div) 1120.2007.01.1.0 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 ...

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... Voltage Reference EN INPUT Functional Description The AAT1120 is a high performance 500mA, 1.5MHz monolithic step-down converter designed to operate with an input voltage range of 2.7V to 5.5V. The converter operates at 1.5MHz, which minimizes the size of external components. Typical values are 3.3μH for the output inductor and 4.7μF for the ceramic output capacitor ...

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... A In this case, a standard 4.7μH value is selected. For most designs, the AAT1120 operates with an inductor value of 1μH to 4.7μH. Table 1 displays inductor values for the AAT1120 with different output voltage 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 ...

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... The input capacitor provides a low impedance loop . The calculated for the edges of pulsed current drawn by the AAT1120. 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 O ⎠ ...

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... With enhanced transient response for extreme pulsed load application, an external feed-forward capacitor, (C3 in Figure 1), can be added. V (V) OUT S 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.8 1.85 2.0 2.5 3.3 Table 2: Adjustable Resistor Values For AAT1120 1 V · · OUT IN(MAX) L · F · · IN(MAX) V 3.3V ⎞ ⎛ ⎞ OUT -1 · ...

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... Thermal Calculations There are three types of losses associated with the AAT1120 step-down converter: switching loss- es, conduction losses, and quiescent current loss- es. Conduction losses are associated with the R characteristics of the power output switch- DS(ON) ing devices. Switching losses are dominated by the gate charge of the power output switching devices ...

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... Layout The suggested PCB layout for the AAT1120 in an STDFN22-8 package is shown in Figures 2, 3, and 4. The following guidelines should be used to help ensure a proper layout. 1. The input capacitor (C1) should connect as closely as possible to VP (Pin 1), PGND (Pin 8), and GND (Pin and L1 should be connected as closely as pos- sible ...

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... IN(MAX esr · 5mΩ · (66mA esr RMS 1120.2007.01.1.0 = 200mA LOAD ⋅ 1.8V = 3µH (use 3.0μH; see Table 1) ⎛ ⎞ 1.8V ⋅ 228mA ⎝ ⎠ 4.2V = 4µF (use 4.7µF) 1 1.8V · (4.2V - 1.8V) · = 66mArms = 3.0µH · 1.5MHz · 4.2V 2 · 21.8µW AAT1120 500mA Step-Down Converter 15 ...

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... V ⎞ ⎛ 25mV - ESR · 4 · ⎝ I ⎠ ⎝ 0. 0.1Arms RMS esr · 5mΩ · (0.1A 0.05mW RMS AAT1120 Losses I 2 · (R · DS(ON)H O DS(ON TOTAL · F · · 0.2 2 · (0.59 Ω · 1.8V + 0.42Ω · [4.2V - 1.8V ...

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... AAT1120 1 L1 (μH) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 2.2 2.7 3.0/3.3 3.0/3.3 3.0/3.3 3.9/4.2 5.6 DCR Size (mm) (mΩ Ω ) LxWxH Type 88 3.0x3.0x1.0 Shielded 115 3.0x3.0x1.0 Shielded 135 3.0x3.0x1.0 Shielded 150 3.0x3.0x1.0 Shielded 180 3.0x3.0x1.0 ...

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... Manufacturer Part Number Murata GRM118R60J475KE19B Murata GRM188R60J106ME47D 18 500mA Step-Down Converter Value (μF) 4.7 10 Table 5: Surface Mount Capacitors. AAT1120 Voltage Temp. Case Rating Co. Size 6.3 X5R 0603 6.3 X5R 0603 1120.2007.01.1.0 ...

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... A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection. 1120.2007.01.1.0 500mA Step-Down Converter Marking Part Number (Tape and Reel) 1 VQXYY AAT1120IES-0.6-T1 STDFN22-8 Detail "A" 0.80 ± 0.05 Bottom View 0.35 ± 0.05 Pin 1 Indicator (optional) Detail "A" AAT1120 2 19 ...

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... AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are regis- tered trademarks or trademarks of their respective holders. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737- 4600 Fax (408) 737- 4611 20 AAT1120 500mA Step-Down Converter 1120.2007.01.1.0 ...