RT8269 RICHTEK [Richtek Technology Corporation], RT8269 Datasheet

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... Step-Down Converter General Description The RT8269 is a high voltage buck converter that can support the input voltage range from 4.75V to 24V and the output current can 3A. Current Mode operation provides fast transient response and eases loop stabilization. ...

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... RT8269 Table 1. Recommended Component Selection V (V) R1 (kΩ) R2 (kΩ) OUT 15 153 10 100 3.3 25.8 2.5 17 1.8 9.1 1.2 3 Functional Pin Description Pin No. Pin Name 1 BOOT 2 VIN GND 9 (Exposed Pad COMP www.richtek.com 2 R (kΩ) C ( ...

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... Junction Temperature Range ------------------------------------------------------------------------------ −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------ −40°C to 85°C DS8269-02 March 2011 Oscillator 400kHz/120kHz V CC Foldback Control 0. Comparator Comparator 0.92V + 680µA/V FB COMP (Note 1) (Note 4) Current Sense Slope Comp Amplifier + - Logic + - Current SW RT8269 VA BOOT SW GND + 0.3V) IN − 0.3V 6V) SW www.richtek.com 3 ...

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... RT8269 Electrical Characteristics (V = 12V 25°C unless otherwise specified Parameter Feedback Reference Voltage High Side Switch-On Resistance Low Side Switch-On Resistance Switch Leakage Current Limit Current Sense Transconductance Error Amplifier Tansconductance Oscillator Frequency Short Circuit Oscillation Frequency Maximum Duty Cycle ...

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... V IN 3.250 -50 - Temperature (°C) Frequency vs. Temperature 420 410 400 390 V = 24V 380 12V 4.75V 370 IN 360 350 V OUT 340 -50 - Temperature (°C) RT8269 = 3.3V OUT 12V 3.3V OUT 75 100 125 = 3.3V OUT 75 100 125 www.richtek.com 5 ...

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... RT8269 Current Limit vs. Duty Cycle 6.0 5.5 5.0 4.5 4.0 3 4.75V to 24V OUT 3 Duty Cycle (%) Power On from 12V (5V/Div) V OUT (2V/Div (1A/Div) Time (5ms/Div) Output Ripple V OUT (10mV/Div (10V/Div (2A/Div 12V Time (1μs/Div) www.richtek.com 100 = 3 ...

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... Load Transient Response V OUT (100mV/Div) I OUT (2A/Div 12V Time (250μs/Div) DS8269-02 March 2011 (100mV/Div) = 3.3V 0. OUT OUT Load Transient Response V OUT I OUT (2A/Div 12V 3.3V OUT Time (250μs/Div) RT8269 = 1. OUT www.richtek.com 7 ...

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... Figure 2. External Bootstrap Diode www.richtek.com 8 Soft-Start The RT8269 contains an external soft-start clamp that gradually raises the output voltage. The soft-start timming can be programed by the external capacitor between SS pin and GND. The chip provides a 10μA charge current for the external capacitor 0.1μF capacitor is used to set the soft-start and its period will be 10ms(typ ...

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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 RT8269 www.richtek.com 9 ...

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... T A the junction to ambient thermal resistance. For recommended operating conditions specification of RT8269, the maximum junction temperature is 125°C. The junction to ambient thermal resistance θ dependent. For SOP-8 (Exposed Pad) package, the thermal resistance θ is 75°C/W on the standard JEDEC JA 51-7 four-layers thermal test board ...

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... COMP GND V OUT The resistor divider must be connected as close to the device as possible. Current Rating (A) Dimensions (mm) 25 4.3 34 3.4 Case Size 10 1206 10 1206 10 1206 47 1206 47 1210 47 1210 22 1210 22 1210 Package DO-214AC DO-214AB DO-214AB DO-214AB RT8269 10 x 9 www.richtek.com 11 ...

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... RT8269 Outline Dimension EXPOSED THERMAL PAD (Bottom of Package) Symbol Option 1 Option 2 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 ...