S-8550AA-M5T1G Seiko Instruments, S-8550AA-M5T1G Datasheet
S-8550AA-M5T1G
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S-8550AA-M5T1G Summary of contents
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... PWM controller, an under voltage lockout circuit (UVLO), a current limit circuit, and a power MOS FET. The oscillation frequency is high at 1.2 MHz high efficiency, large output current, step-down switching regulator can be achieved by using small external parts. ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS S-8550/8551 Series Block Diagram 1. SOT-23 *1. Parasitic diode 2. SNT- *1. Parasitic diode 2 Current limit circuit IC internal power supply Error amplifier − + PWM control + − circuit Reference PWM comparator voltage Triangular wave generation circuit ON/OFF ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS Rev.4.0 _00 Product Name Structure 1. Product name S-855 − xxxx x *1. Refer to the tape specifications at the end of this book. *2. Refer to Table 1 to Table 3 of “ 2. Packages Package Name SOT-23-5 MP005-A-P-SD SNT-8A PH008-A-P-SD ...
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... VIN IC power supply pin *2 6 PVSS Power GND pin * connection 8 CONT External inductor connection pin *1. The NC pin is electrically open. The NC pin can be connected to VIN, VSS or PVSS. *2. Connect VSS and PVSS to GND. Seiko Instruments Inc. Rev.4.0 _00 Description Description Description ...
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... The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. 2. Since this IC has a built-in power MOS FET, make sure that dissipation of the power MOS FET does not exceed the allowable power dissipation of the package. (Refer to Figure 5.) Generally, dissipation of a switching regulator can be calculated by the following equation. Dissipation = (100 (%) − ...
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... C TDK Corporation OUT R 36 kΩ Rohm Co., Ltd. FB1 R 18 kΩ Rohm Co., Ltd. FB2 68 pF Murata Manufacturing Co., Ltd. FB Seiko Instruments Inc. = 1.8 V (the conditions in Table 6 +25°C) OUT Min. Typ. Max. Unit ⎯ 2.0 5.5 V ⎯ 1.1 4.0 V 0.588 0.6 0.612 V ⎯ ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS Rev.4.0 _00 Test Circuits 1. A *1. PVSS pin is unavailable for the S-8550/8551 series with SOT-23-5. 2. *1. PVSS pin is unavailable for the S-8550/8551 series with SOT-23-5. VIN CONT FB C S-8550/8551Series IN ON/OFF *1 VSS PVSS Figure 6 ...
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... The soft-start circuit built in the S-8550/8551 Series controls the rush current and the overshoot of the output voltage when powering on, the ON/OFF pin is switched from the “L” level to the “H” level, or the UVLO operation is released. A reference voltage adjustment method is adopted as the soft-start method. ...
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... A slight overshoot is generated in the output voltage when the current limit is released. The current limit detection value is fixed (typ.) in the IC. If the time taken for the current limit to be detected is shorter than the time required for the current limit circuit in the IC to detect, the current value that is actually limited increases ...
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... A step-down switching regulator starts current supply by the input voltage (V turned on and holds energy in the inductor at the same time. When the Pch power MOS FET is turned off, the current held in the inductor is released. The released current flows in the smoothing circuit, with the energy loss ...
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... OUT made 0 mA and no backflow current flows. When an input capacitor (C current to flow in the power supply. Be sure to connect an input capacitor to reduce backflow current to the power supply (see Figure 12). The above presents the conditions required to prevent backflow current from flowing, which is only a guideline. ...
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... L is decreased further, the current drive capability of the external transistor is insufficient and I If the L value is increased, the loss due to I maximum at a certain L value. Further increasing L decreases the efficiency due to the increased loss of the DC resistance of the inductor. The recommended L value for the S-8550/8551 Series is 3.3 μH. ...
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... However, since the gain becomes higher in the range of high frequency, the total phase of feedback loop delays 180° or more by setting the zero point frequency in the significantly lower range result, the gain cannot lower in the frequency range thus the operation might be unstable. Determine the proper value after the sufficient evaluation under the actual condition ...
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... Parasitic diode 2. SNT-8A Error amplifier FB Reference voltage 4.7 μF *1. Parasitic diode Caution The above connection diagram and constant will not guarantee successful operation. Perform thorough evaluation using an actual application to set the constants. 14 Current limit circuit IC internal power supply − + PWM control + − ...
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... Although the IC contains a static electricity protection circuit, static electricity or voltage that exceeds the limit of the protection circuit should not be applied. • The power dissipation of the IC greatly varies depending on the size and material of the board to be connected. Perform sufficient evaluation using an actual application before designing. • ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS S-8550/8551 Series Characteristics (Typical Data) 1. Example of Major Power Supply Dependence Characteristics (Ta = 25° Current consumption 1 (I 500 400 300 200 100 0 2.0 2.5 3.0 3 Oscillation frequency (f osc 1.38 1.34 1.30 1.26 1.22 1 ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS Rev.4.0 _00 voltage (V ) vs. Input voltage (V FB 612 608 604 600 596 592 588 2.0 2.5 3.0 3 Example of Major Temperature Characteristics (Ta = −40 to 85° Current consumption 1 (I SS1 500 400 V 300 200 100 0 −40 − [° Oscillation frequency (f osc 1 ...
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... Ta [° UVLO detection voltage (V 1.80 1.75 1.70 1.65 1.60 1.55 1.50 1.45 1.40 −40 − [°C] 3. Examples of Transient Response Characteristics (Unless otherwise specified, the used parts are ones shown Powering ON (V OUT ( OUT OUT 0 − −0.2 0 0.2 0.4 ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS Rev.4.0 _00 3. 3 Power supply fluctuations (V = 2.6 V → 3.6 V → 2 mA, V OUT 2.2 2.0 V OUT 1.8 1.6 1.4 −0.1 0 0.1 0.2 0.3 0.4 t [ms Load fluctuations (V OUT ( 0.1 mA → 100 mA → 0.1 mA ...
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... Input capacitor C3216X7R1E475K Output capacitor C3216X7R1C106K Caution The values of the external parts are based on the materials provided by each manufacturer. However, consider the characteristics of the original materials when using the above products. 2. Output current (I ) vs. Efficiency (η) Characteristics and Output current (I OUT = 1 kΩ ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS Rev.4.0 _00 = 3 kΩ OUT FB1 Output current (I (1) OUT 100 3 5 OUT = 4 kΩ OUT FB1 Output current (I (1) OUT 100 4 5 OUT 3. Output current (I ) vs. Ripple voltage (V OUT = 1 kΩ ...
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... STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS S-8550/8551 Series = 1 kΩ OUT FB1 ( 3 OUT = 3 kΩ OUT FB1 ( 3 OUT = 4 kΩ OUT FB1 ( 5 OUT kΩ) FB2 (2) V 100 1000 [mA kΩ) FB2 (2) V 100 1000 [mA kΩ) FB2 100 ...
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... Product Name S-8550AA-M5T1x (2) SNT-8A SNT-8A Top view Product name vs. Product code (a) S-8550 Series Product name S-8550AA-I8T1x Remark Please select products of environmental code = U for Sn 100%, halogen-free products. (1) to (3) : Product code (Refer to Product name vs. Product code.) (4) : Lot number (b) S-8551 Series Product Code (1) (2) ( S-8551AA-M5T1x ...
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... Seiko Instruments Inc. is strictly prohibited. • The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Seiko Instruments Inc. ...