AAT1152 Advanced Analogic Technologies, AAT1152 Datasheet
AAT1152
Available stocks
Related parts for AAT1152
AAT1152 Summary of contents
Page 1
... Power MOSFETs, the current-mode controlled IC provides high efficiency using syn- chronous rectification. Fully internally compensat- ed, the AAT1152 simplifies system design and low- ers external part count. The AAT1152 features a Power Good (POK) func- tion which monitors the output, alerting the system if the output voltage falls out of regulation ...
Page 2
... Small Signal Filtered Bias Supply Input supply for converter power stage Inductor connection pin Power Good indicator. Open-drain output is low when V out of regulation. Power ground return for output stage MSOP-8 P GND POK SGND AAT1152 falls OUT 1152.2003.01.0.9 ...
Page 3
... Maximum Power Dissipation (MSOP-8) D Note 2: Mounted on a demo board. Recommended Operating Conditions Symbol Description T Ambient Temperature Range 1152.2003.01.0.9 850kHz 1A Synchronous Buck DC/DC Converter (T =25°C unless otherwise noted HBM AAT1152 Value Units -40 to 150 °C 300 ° ...
Page 4
... 25° 25° 25° 2 2 rising IN V falling 5. Ramping Ramping Down FB AAT1152 Min Typ Max Units 2.7 5.5 V -1.0 +1.0 % -2.0 +2.0 1.2 A 160 300 µ 0.2 %/V 700 850 1000 kHz 110 150 m 100 150 m 1 µ ...
Page 5
... Synchronous Buck DC/DC Converter 170 150 130 110 100 120 -20 1.2 1.1 1 0.9 0.8 4.5 5 5.5 0.7 2.5 Oscillator Frequency Variation vs. Temperature -10 4.5 5 5.5 -20 AAT1152 Low Side R vs. Temperature DS(ON) 3.6V 2.7V 5.5V 4. Temperature ( C) Enable Threshold vs. Input Voltage 3.5 4 4.5 Input Voltage (V) V =3. ...
Page 6
... Loop Gain and Phase vs. Output Capacitor -16 -24 -32 -40 10 4.5 5 5.5 AAT1152 Line Regulation V =1.5V OUT I = 1.0A OUT I = 0.4A OUT 5 3 3.5 4 4.5 Input Voltage (V) Load Regulation V =3.3V, V =5.0V OUT IN 150 300 450 600 750 900 Output Current ( ...
Page 7
... Inductor Current 500mA/div V =3. =1.5V OUT I =0.25 to 1.2A LOAD V OUT 5mV/div BW=20MHz V =3. =1.5V OUT I =1A OUT LX 2V/div AAT1152 Non-Switching I vs. Temperature Temperature ( C) Transient Response V OUT 20 s/div Output Ripple 1 ...
Page 8
... Typical Characteristics Output Ripple 3.3V, No Load V OUT 5mV/div BW=20MHz V =5. =3.3V OUT I =0A OUT LX 2V/div 500nsec/div 8 850kHz 1A Synchronous Buck DC/DC Converter V OUT 5mV/div BW=20MHz V =5. =3.3V OUT I =1A OUT LX 2V/div AAT1152 Output Ripple 3.3V, 1A Load 500nsec/div 1152.2003.01.0.9 ...
Page 9
... Applications Information 850 kHz 1 Amp DC-DC Synchronous Buck Converter Control Loop The AAT1152 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 ...
Page 10
... Thermal protection completely disables switching when internal dissipation becomes excessive, protecting the device from damage. The junction over-temperature threshold is 140°C with 15°C of hysteresis. Current Limit Characteristic 3 5. 3.3V O 2.5 Figure 4 schematic 2 1 =3. 1.5V O Figure 3 schematic 0 0.5 1 1.5 I (A) OUT Figure 2. AAT1152 2 2.5 1152.2003.01.0.9 ...
Page 11
... 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 AAT1152. A low ESR/ESL ceramic capacitor is ideal for this function. To mini- mize the stray inductance the capacitor should be placed as close as possible to the IC. This keeps ...
Page 12
... For a ceramic capacitor the dissipation due to the RMS current of the capacitor is not a concern. Tantalum capacitors, with sufficiently low ESR to meet output voltage ripple requirements, also have an RMS current rating much greater than that actually seen in this application. AAT1152 Vo+ 1.25V 1A C2 100 ...
Page 13
... Vin+ 2.7V-5. Figure 4: Lithium-Ion to 1.5V Output Converter Figure 5: AAT1152 Layout Top Layer 1152.2003.01.0.9 850kHz 1A Synchronous Buck DC/DC Converter R5 Pok 100k U1 AAT1152-1 100 L1 Vcc Pok 4 100k LX Sgnd Pgnd C3 0 Murata 10 F 6.3V X5R GRM42-6X5R106K6.3 C2 MuRata 100 F 6.3V GRM43-2 X5R 107M 100 F 6.3V L1 Sumida CDRH5D 18- ...
Page 14
... RMS 14 850kHz 1A Synchronous Buck DC/DC Converter Layout Considerations Figures 5 and 6 display the suggested PCB layout for the AAT1152. The most critical aspect of the lay- out is the placement of the input capacitor C1. For proper operation C1 must be placed as close as possible to the AAT1152. Thermal Calculations There are two types of losses associated with the AAT1152 output switching MOSFET, switching losses and conduction losses ...
Page 15
... Output Capacitor Dissipation OUT IN OUT RMS ESR .082 ESR COUT RMS AAT1152 Dissipation · (R · · DSON(H) O DSON( (0.14 · 1.5V + 0.145 · (3.6V - 1.5V · 150 C/W · 0.203W = 115 C J(MAX) AMB JA LOSS 1152 ...
Page 16
... Value Current DCR 4.7µH 1.4A .038 3.5µH 1.34A .073 4.2µH 2.2A .031 4.1µH 1.95A .057 4.7µH 2.7A .041 4.7µH 2.2A .025 Value Voltage 100µF 6.3V 100µF 6.3V 47µF 6.3V 10µF 6.3V 10µF 6.3V AAT1152 Size (mm Type 5.9 6.1 2.8 Shielded 5.0 5.0 2.0 Shielded 5.7 5.7 3.0 Shielded 5.7 5.7 2.0 Shielded 5.0 5.0 4.7 Non-shielded 6.3 6.3 4.7 Shielded Temp. Co. Case X5R 1812 ...
Page 17
... All dimensions in millimeters. 1152.2003.01.0.9 850kHz 1A Synchronous Buck DC/DC Converter Package Marking MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8 1.95 BSC 0.254 BSC 3.00 0. 0.65 BSC 0.30 0.08 AAT1152 Part Number (Tape and Reel) AAT1152IKS-1.0-T1 AAT1152IKS-1.1-T1 AAT1152IKS-1.2-T1 AAT1152IKS-1.5-T1 AAT1152IKS-1.8-T1 AAT1152IKS-2.0-T1 AAT1152IKS-2.5-T1 AAT1152IKS-3.0-T1 AAT1152IKS-3.3- 0.60 0.20 0.155 0.075 17 ...
Page 18
... 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 18 850kHz 1A Synchronous Buck DC/DC Converter AAT1152 1152.2003.01.0.9 ...