RT8270 RICHTEK [Richtek Technology Corporation], RT8270 Datasheet
RT8270
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RT8270 Summary of contents
Page 1
... Current Mode operation provides fast transient response and eases loop stabilization. The chip provides protection functions such as cycle-by- cycle current limiting and thermal shutdown protection. In shutdown mode, the regulator draws 25μA of supply current. The RT8270 is available in a SOP-8 surface mount package. Ordering Information RT8270 Package Type ...
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... RT8270 Table 1. Recommended Component Selection V (V) R1 (kΩ) R2 (kΩ) OUT 2.5 10.45 10 1.8 4.75 10 1.222 0 10 Functional Pin Description Pin No. Pin Name High Side Gate Drive Boost Input. BOOT supplies the drive for the high side N-MOSFET 1 BOOT switch. Connect a 10nF or greater capacitor from SW to BOOT to power the high side switch ...
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... DS(ON)1 R DS(ON 0V Duty = 90%; V LIM BOOT−SW G Output Current ΔI = ±10μ 0.8V MAX RT8270 IN − 0.3V Min Typ Max 1.184 1.222 1.258 -- 0. 4. 2.5 COMP -- 780 -- 1.2 -- 440 -- 80 -- 100 4 4.2 4.5 -- 300 ...
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... RT8270 Parameter Shutdown Current Quiescent Current Thermal Shutdown Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. θ ...
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... Reference Voltage vs. Input Voltage V = 4.75V to 22V Input Voltage (V) Output Voltage vs. Temperature V = 12V OUT -50 - Temperature Frequency vs. Temperature 1.40 1.35 1.30 1.25 1.20 1.15 1.10 1. 1.00 -50 - Temperature RT8270 = 3.3V OUT 3.3V OUT 75 100 125 (°C) = 12V 3.3V OUT 75 100 125 (°C) www.richtek.com 5 ...
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... RT8270 Current Limit vs. Input Voltage 4.50 4.25 4.00 3.75 3.50 3.25 3.00 2. Input Voltage (V) Load Transient Response V OUT (100mV/Div) I OUT (1A/Div 12V Time (100μs/Div) Power On from (2V/Div) V OUT (2V/Div) I OUT (2A/Div 12V Time (5ms/Div) www.richtek.com 6 = 4.75 to 22V 3.3V IN OUT 14 16 ...
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... Power On from (5V/Div) V OUT (2V/Div (1A/Div 12V Time (5ms/Div) DS8270-01 March 2011 IN V OUT (10mV/Div (10V/Div (1A/Div) = 3.3V OUT OUT RT8270 Switching V = 12V 3.3V OUT OUT Time (500ns/Div) www.richtek.com 7 ...
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... RT8270. BOOT RT8270 SW Figure 2 www.richtek.com 8 Soft-Start The RT8270 contains an internal soft-start clamp that gradually raises the output voltage. The soft-start time is designed by the internal capacitor. The typical soft-start time is 2ms. Inductor Selection V The inductor value and operating frequency determine the OUT ...
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... OUT , is determined by : OUT ⎡ ⎤ 1 ≤ Δ ESR ⎢ ⎥ OUT L ⎣ ⎦ 8fC OUT increases with input voltage. Multiple best, this ringing can couple to the output IN large enough to damage the IN RT8270 www.richtek.com 9 ...
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... D(MAX) SOP-8 packages The maximum power dissipation depends on operating ambient temperature for fixed θ resistance . For RT8270 packages, the Figure derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. www.richtek.com 10 Figure 3 ...
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... V (V) I (A) RRM OUT GND The feedback and compensation components must be connected as close to the device as possible COMP OUT R2 GND Capacitance (μF) Case Size 10 1206 10 1206 10 1206 22 1210 22 1210 22 1210 Package SMA DO-214AA RT8270 www.richtek.com 11 ...
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... RT8270 Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time ...