RT8253A RICHTEK [Richtek Technology Corporation], RT8253A Datasheet
RT8253A
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RT8253A Summary of contents
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... Synchronous Step-Down Converter General Description The RT8253A is a high efficiency, monolithic synchronous step-down DC/DC converter that can deliver output current from a 4.5V to 23V input supply. The RT8253A's current mode architecture and external compensation allow the transient response to be optimized over a wide range of loads and output capacitors. ...
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... COMP to GND is required. Enable Input Pin. A logic high enables the converter; a logic low forces the RT8253A into shutdown mode reducing the supply current to less than 3μA. Attach this pin to VIN with a 100kΩ pull up resistor for automatic startup. ...
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... VIN Internal Regulator Shutdown V Comparator Lockout Comparator 2. 6µA SS DS8253A-02 March 2011 Oscillator 340kHz / 110kHz CC Foldback Control 0. Comparator 0. COMP Current Sense Amplifier Slope Comp + - S Q 85mΩ 85mΩ - Current Comparator RT8253A V A BOOT SW GND www.richtek.com 3 ...
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... RT8253A Absolute Maximum Ratings ------------------------------------------------------------------------------------------------------------------ −0.3V to 25V ----------------------------------------------------------------------------------------------------------------- −0. BOOT ------------------------------------------------------------------------------------------------------------- (SW−0.3V) to (SW + 6V) All Other Voltages ---------------------------------------------------------------------------------------------- −0. BOOT − SW ----------------------------------------------------------------------------------------------------- −0. Power Dissipation 25° SOP-8 (Exposed Pad) ---------------------------------------------------------------------------------------- 1.333W Package Thermal Resistance (Note 2) SOP-8 (Exposed Pad), θ ----------------------------------------------------------------------------------- 75°C/W JA SOP-8 (Exposed Pad), θ ...
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... Note 4. The device is not guaranteed to function outside its operating conditions. DS8253A-02 March 2011 Symbol Test Conditions V Rising 0.1μ 25° high effective thermal conductivity four-layer test board of A RT8253A Min Typ Max Unit 3.8 4.2 4 320 -- mV 2 0.4 μ ...
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... RT8253A Typical Operating Characteristics Efficiency vs. Load Current 104 4. 12V 23V 0.001 0.010 Load Current (A) Reference Voltage vs. Temperature 0.820 0.815 0.810 0.805 0.800 0.795 0.790 0.785 -50 - Temperature (°C) Switching Ferquency vs. Input Voltage ...
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... Load Transient Response V OUT I LOAD (2A/Div 12V 1. OUT Time (100μs/Div) Switching Waveform V OUT V SW (10V/Div (2A/Div 12V 3.3V OUT Time (1μs/Div) RT8253A = 3.3V OUT 100 125 = 3.3V OUT 1. OUT www.richtek.com 7 ...
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... RT8253A Power On From (5V/Div) V OUT (2V/Div (2A/Div 12V 3.3V OUT Time (4ms/Div) Power On From (5V/Div) V OUT (2V/Div (2A/Div 12V 3.3V OUT Time (4ms/Div) www.richtek.com (10V/Div) V OUT (5V/Div (5A/Div OUT V EN (5V/Div) V OUT ...
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... Figure 2. External Bootstrap Diode & Capacitor Chip Enable and Disable The EN pin is the RT8253A enable input. Drive EN below the precise input falling edge trip level to place the RT8253A in its low power shutdown state. The RT8253A quiescent current drops to lower than 3μA while in shutdown. When ...
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... Hiccup Mode For the RT8253AH, Hiccup Mode Under Voltage Protection (UVP) function is provided. When the FB voltage drops below half of the feedback voltage, V will be triggered and the RT8253AH will shut down for a www.richtek.com 10 period of time and then recover automatically. The Hiccup Mode UVP can reduce input current in short circuit conditions ...
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... RT8253A 10µ (Exposed Pad) COMP GND , but this will decrease the driving capability to the BOOT R * BOOT BOOT 10µH 0.1µF 3 Rs* Cs* R1 31.25k 15k 3.3nF 10k RT8253A V OUT 3.3V/3A C OUT 22µ www.richtek.com 11 ...
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... Loop Compensation The RT8253A is a current mode converter and requires external compensation to have an accurate output voltage regulation with fast transient response. The main concern of compensation deals with the position of the capacitor ESR zero and mid frequency to high frequency gain boost ...
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... P D(MAX) where T the ambient temperature, and θ thermal resistance. For recommended operating condition specifications of the RT8253A, the maximum junction temperature is 125°C and T thermal resistance, θ SOP-8 (Exposed Pad) packages, the thermal resistance, θ , control loop JA C thermal test board ...
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... PCB could radiate excessive noise and contribute to the converter instability with improper layout. Certain points must be considered before starting a layout using the RT8253A (Figure 8). Keep the traces of the main current paths as short and wide as possible. Put the input capacitor as close as possible to the device pins (VIN and GND) ...
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... Y 3.000 3.500 8-Lead SOP (Exposed Pad) Plastic Package Richtek Technology Corporation Taipei Office (Marketing) 5F, No. 95, Minchiuan Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)86672399 Fax: (8862)86672377 Email: marketing@richtek.com RT8253A Dimensions In Inches Min Max 0.189 0.197 0.150 0.157 ...