AAT1143 Advanced Analogic Technologies, AAT1143 Datasheet
AAT1143
Available stocks
Related parts for AAT1143
AAT1143 Summary of contents
Page 1
... Its low supply cur- rent, small size, and high switching frequency make the AAT1143 the ideal choice for portable applications. The AAT1143 is available in either a fixed version with internal feedback or a programmable version with external feedback resistors. It can deliver 400mA of load current while maintaining a low 25µ ...
Page 2
... MOSFETs. 5 AGND Non-power signal ground pin PGND Main power ground return pin. Connect to the output and input capacitor return. Pin Configuration 2 1MHz 400mA Step-Down Converter SC70JW-8 (Top View) EN PGND 8 1 OUT PGND 2 7 VIN PGND AGND 4 5 AAT1143 1143.2005.09.1.7 ...
Page 3
... 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. 1143.2005.09.1.7 1MHz 400mA Step-Down Converter 1 2 (SC70JW-8) AAT1143 Value Units 6 ...
Page 4
... EN(H) I Input Low Current EN 1. The AAT1143 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. For adjustable version with higher than 2.5V output, please consult your AnalogicTech representative. 4 ...
Page 5
... Input Voltage (V) 1143.2005.09.1.7 1MHz 400mA Step-Down Converter 2.0 1.0 0.0 -1.0 -2.0 100 1000 0.1 2.0 1.0 0.0 -1.0 -2.0 100 1000 0.1 Output Voltage Error vs. Temperature 2.0 1.0 0.0 -1.0 -2.0 4.7 5.1 5.5 -40 AAT1143 Load Regulation = 2.5V 4.7µ µ OUT 100 Output Current (mA) DC Regulation = 1.8V 4.7µ µ OUT 100 Output Current (mA 3.6V ...
Page 6
... Quiescent Current vs. Input Voltage 2 100 (30mA - 300mA; V 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 5.0 5.5 6.0 (30mA - 300mA 10µ µ 100pF; see Figure 1) 0.1 0.0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7 5.0 5.5 6.0 AAT1143 (V = 1.8V) O 85°C 25°C -40°C 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) Load Transient Response = 1.8V 10µ µ 3.6V OUT 1.4 1.2 1.0 300mA 0.8 0.6 30mA 0.4 0.2 0.0 -0.2 Time (25µs/div) Load Transient Response = 3.6V 1.8V; IN OUT 1.4 1 ...
Page 7
... OUT -0.3 -0.35 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) Output Ripple (V = 3.6V 1.8V; 400mA) IN OUT -20 -40 -60 -80 -100 -120 Time (250ns/div) 1143.2005.09.1.7 1MHz 400mA Step-Down Converter 1.90 1.4 1.85 1.2 1.80 1.0 1.75 0.8 1.70 0.6 1.65 0.4 1.60 0.2 1.55 0.0 -0.2 1.50 4.0 3.0 2.0 1 10mA OUT 0.0 -1.0 -2.0 -3.0 -4.0 5.0 5.5 6.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 AAT1143 Line Transient (V = 1.8V @ 400mA) OUT 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 Time (25µ µ s/div) Soft Start (V = 3.6V 1.8V; 400mA) IN OUT 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -0.5 250µ µ s/div 7 ...
Page 8
... Note: For adjustable version, the internal feedback divider is omitted and the FB pin is tied directly to the internal error amplifier. 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 ...
Page 9
... V Figure 1: Enhanced Transient Response Schematic. Control Loop 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% ...
Page 10
... 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. 0.75 ⋅ V 0.75 ⋅ ...
Page 11
... 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 ...
Page 12
... Figure 2: AAT1143 Evaluation Board Top Side. The maximum output capacitor RMS ripple current is given by · (V OUT IN(MAX · RMS(MAX) L · F · · 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. ...
Page 13
... Table 2: Adjustable Resistor Values For Use With 0.6V Step-Down Converter. V OUT 4.7µF GND GND2 Figure 5: AAT1143 Adjustable Evaluation Board Schematic. 1143.2005.09.1.7 1MHz 400mA Step-Down Converter Thermal Calculations There are three types of losses associated with the AAT1143 step-down converter: switching loss- es, conduction losses, and quiescent current loss- es ...
Page 14
... J(MAX) TOTAL JA 14 1MHz 400mA Step-Down Converter 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. · The input capacitor (C2) should connect closely as possible to V (Pins 6-8). ...
Page 15
... L1 · F · · 3 IN(MAX esr · 5mΩ · (63mA) esr RMS 1143.2005.09.1.7 1MHz 400mA Step-Down Converter (see Table 1) ⎛ ⎞ 1.8V ⋅ 218mA ⎝ ⎠ 4.2V = 4.5µF 1 1.8V · (4.2V - 1.8V) · = 63mArms = 4.7µH · 1.0MHz · 4.2V 2 · 20µW AAT1143 = 300mA LOAD 15 ...
Page 16
... PP - ESR · 4 · F ⎝ ⎠ ⎝ 0. 0.2Arms RMS esr · 5mΩ · (0.2A) = 0.2mW RMS AAT1143 Losses 2 I · (R · DSON(HS) O DSON(LS TOTAL · F · · · (0.725 Ω · 1.8V + 0.7Ω · [4.2V - 1.8V ...
Page 17
... R1 (kΩ Ω Not Used 0 Inductance Max DC (µH) Current (A) 4.7 0.90 10 0.55 4.7 0.45 4.7 0.65 4.7 0.65 4.7 1.10 4.7 0.80 4.7 1.53 4.7 1.30 4.7 0.98 4.7 1.77 AAT1143 L1 (µ 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4 (µH) 4.7 DCR Size (mm) (Ω Ω ) LxWxH Type 0.11 3.8x3.8x1.8 Shielded 0.21 3.8x3.8x1.8 Shielded 0.20 2.5x3.2x2.0 Non-Shielded 0.15 2.5x3.2x2.0 Non-Shielded 0.15 2.5x3.2x1.55 Non-Shielded 0.20 5.5x6.6x1.0 1mm 0 ...
Page 18
... Manufacturer Part Number MuRata GRM21BR61A475KA73L MuRata GRM18BR60J475KE19D MuRata GRM21BR60J106KE19 MuRata GRM21BR60J226ME39 18 1MHz 400mA Step-Down Converter Value 4.7µF 4.7µF 10µF 22µF Table 5: Surface Mount Capacitors. AAT1143 Voltage Temp. Co. Case 10V X5R 0805 6.3V X5R 0603 6.3V X5R 0805 6.3V X5R 0805 1143.2005.09.1.7 ...
Page 19
... Sample stock is generally held on part numbers listed in BOLD. 1143.2005.09.1.7 1MHz 400mA Step-Down Converter Marking 2 NUXYY PBXYY NXXYY PYXYY OKXYY OYXYY SC70JW-8 0.225 ± 0.075 2.00 ± 0.20 0.100 AAT1143 Part Number (Tape and Reel) AAT1143IJS-0.6-T1 AAT1143IJS-1.2-T1 AAT1143IJS-1.5-T1 AAT1143IJS-1.6-T1 AAT1143IJS-1.8-T1 AAT1143IJS-2.5-T1 AAT1143IJS-3.3-T1 0.048REF 0.45 ± 0.10 4° ± 4° 2.10 ± 0. ...
Page 20
... 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 20 1MHz 400mA Step-Down Converter AAT1143 1143.2005.09.1.7 ...