AS1341 austriamicrosystems AG, AS1341 Datasheet
AS1341
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AS1341 Summary of contents
Page 1
... V supply voltages 20V. An integrated current-limited 0.4Ω MOSFET delivers load currents up to 600mA. The AS1341 also includes a 100% duty cycle LDO mode with a low dropout of only 250mV for high effi- ciency if input voltages is in the range of the output volt- age. ...
Page 2
... Peak Current Control Input. Connect this pin GND to set peak current limit (see Setting Current Limit on page 10). Shutdown Input. A low on this pin puts the AS1341 into shutdown mode. Supply current is reduced to 0.8µA and LX goes high-impedance. Regulated Output Voltage High-Impedance Sense Input. This pin is connected to the internal resistor-divider network ...
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... AS1341 Data Sheet - Absolute Maximum Ratings Stresses beyond those listed in and functional operation of the device at these or any other conditions beyond those indicated in istics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect www ...
Page 4
... AS1341 Data Sheet - Electrical Characteristics DC Electrical Characteristics V = +12V, SHDNN = www.datasheet4u.com Specifications based on circuit shown in Table 3. Electrical Characteristics Symbol Parameter V Input Voltage Range IN Output Voltage (Preset Output) ...
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... AS1341 Data Sheet - Typical Operating Characteristics www.datasheet4u.com Figure 3. Efficiency vs. I OUT 100 ILIMIT = high 0 Output Current (mA) Figure 5. Efficiency vs. I OUT ...
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... AS1341 Data Sheet - Figure 9. Efficiency vs. Input Voltage; Circuit 1 or Circuit 3 100 95 www.datasheet4u.com cui t 1: VOUT=3.3V, IOUT=500mA cui t 1: VOUT=5V, IOUT=500mA Ci r cui t 3: VOUT=3.3V, IOUT=250mA ...
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... AS1341 Data Sheet - Figure 15. Load Regulation 12V OUT 5.15 5.1 www.datasheet4u.com 5.05 ILIMIT = high 5 ILIMIT = low 4.95 4.9 4.85 0 100 200 Output Current (mA) Figure 17. Line Transient Response 500mA OUT 200µs/Div Figure 19. LX Waveform ...
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... ILIMIT Current-Limit Control The AS1341 uses a proprietary current-limiting control scheme with operation up to 100% duty cycle. The DC-DC con- verter pulses as needed to maintain regulation, resulting in a variable switching frequency that increases with the load. This eliminates the high-supply currents associated with conventional constant-frequency pulse-width-modulation (PWM) controllers that unnecessarily switch the MOSFET ...
Page 9
... The AS1341 provides a Power OK output (POK) that goes high-impedance when the output reaches 92.5% of its reg- ulation point. POK goes low when the output is below 92.5% of the regulation point and the AS1341 is turned on (IN ≥ 4.5V and SHDNN ≥ 2.4V). A 12kΩ to 1MΩ pullup resistor between pin POK and pin IN or pin OUT or another volt- age (≤ ...
Page 10
... Inductor Selection on page 10) Inductor Selection The AS1341 operates with a wide range of inductance values. For most applications, values between 10µH and 47µH work best with the controller’s high switching frequency. Larger inductor values will reduce the switching frequency and thereby improve efficiency and EMI. ...
Page 11
... LQH66SN-470M03 LQH55DN-470M03 Maximum Output Current The AS1341 output current determines the regulator’s switching frequency. When the converter approaches continu- ous mode, the output voltage falls out of regulation. For the typical application, the maximum output current is approxi- mately: For low-input voltages, the maximum on-time may be reached and the load current is limited by: www ...
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... AS1341 Data Sheet - Output Capacitor Choose the output capacitor to service the maximum load current with acceptable voltage ripple. The output ripple has two components: variations in the charge stored in the output capacitor with each LX pulse, and the voltage drop across the capacitor’ ...
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... PC Board Layout and Grounding High switching frequencies and large peak currents make PC board layout an important part of AS1341-based designs. Good PCB layout can avoid switching noise being introduced into the feedback path, resulting in jitter, insta- bility, or degraded performance. - High-power traces ...
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... AS1341 Data Sheet - Package Drawings and Markings Figure 23. TDFN-8 3x3mm Package www.datasheet4u.com DEX AREA aaa /2) 4 TOP VIEW e ODD TERMINAL SIDE Symbol Min A 0.70 A1 ...
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... AS1341 Data Sheet - Ordering Information The device is available as the standard products shown in Table 9. Ordering Information www.datasheet4u.com Model AS1341-BTDT 20V, 600mA, 100% Duty Cycle, Step-Down Converter www.austriamicrosystems.com Table 9. Description Revision 1.00 Delivery Form ...
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... AS1341 Data Sheet Copyrights Copyright © 1997-2007, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, trans- lated, stored, or used without the prior written consent of the copyright owner. www.datasheet4u.com All products and companies mentioned are trademarks or registered trademarks of their respective companies. ...