ncp3170 ON Semiconductor, ncp3170 Datasheet
ncp3170
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ncp3170 Summary of contents
Page 1
... Synchronous PWM Switching Converter The NCP3170 is a flexible synchronous PWM Switching Buck Regulator. The NCP3170 operates from 4 sourcing and is capable of producing output voltages as low as 0.8 V. The NCP3170 also incorporates current mode control. To reduce the number of external components, a number of features are internally set including soft start, power good detection, and switching frequency. The NCP3170 is currently available in an SOIC− ...
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... Clamp Slope Compensation Pulse by Oscillator S Q SET Pulse Current R Q Limit CLR logic Zero Over Current Temperature Detection Protection Figure 2. NCP3170 Block Diagram Description http://onsemi.com 2 VIN VCW VCL 0.030V/A Current Sense VIN PDRV VCW VCL NDRV VSW PGND VSW ...
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ABSOLUTE MAXIMUM RATINGS (measured vs. GND pin 3, unless otherwise noted) Rating Main Supply Voltage Input Voltage between PGND and AGND PWM Feedback Voltage Error Amplifier Voltage Enable Voltage PG Voltage VSW to AGND or PGND VSW to AGND or ...
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... OUT Conditions (Note 5) NCP3170A NCP3170B (Note (Note 5) V Rising Edge (Note Falling Edge (Note 5) IN NCP3170A Enable = V IN NCP3170B NCP3170A NCP3170B V = VCOMP FB (Note 25°C A (Note 4) (Note 4) (Note (Note 5) ...
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TYPICAL PERFORMANCE CHARACTERISTICS (Circuit from Figure 25°C, V Figure 3. Light Load (DCM) Operation 1 ms/DIV Figure 5. Start−Up into Full Load 1 ms/DIV Figure 7. 50% to 100% Load Transient 100 ms/DIV = ...
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... V unless otherwise specified OUT 2.1 2.0 1.9 Input Voltage = 12 V 1.8 1.7 1.6 1.5 1.4 1 110 130 −50 −30 Figure 10. NCP3170 Enabled Current vs. 503 502 Input Voltage = 4.5 V 501 500 499 498 497 496 70 90 110 130 −50 −30 Figure 12. Switching Frequency vs. 880 Over Voltage Protection Falling 875 ...
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TYPICAL PERFORMANCE CHARACTERISTICS (Circuit from Figure 25°C, V 130 120 110 Input Voltage = 4.5 V 100 90 Input Voltage = −50 −30 − TEMPERATURE (°C) Figure ...
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... NCP3170A Efficiency and Thermal Derating 100 OUTPUT CURRENT (A) Figure 20. Efficiency (V IN Current Thermal derating curves for the SOIC−8 package part under typical input and output conditions based on the evaluation board. ...
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... NCP3170B Efficiency and Thermal Derating 100 OUTPUT CURRENT (A) Figure 24 MHz Efficiency Thermal derating curves for the SOIC−8 package part under typical input and output conditions based on the evaluation board. ...
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... The NCP3170 is a current−mode, step down regulator with an integrated high−side PMOS switch and a low−side NMOS switch. It operates from a 4 input voltage range and supplies load current. The duty ratio can be adjusted from 8% to 92% allowing a wide output voltage range. Features include enable control, Power− ...
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... MOSFETS, and ensuring the output inductor does not saturate during start−up. Pre−Bias Start−up When starting into a pre−bias load, the NCP3170 will not discharge the output capacitors. The soft start begins with the internal reference at ground. Both the high side switch and low side switches are turned off ...
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... The NCP3170 switching frequency is fixed and set by an internal oscillator. The practical switching frequency could range from 450 kHz to 550 kHz for the NCP3170A and 900 kHz to 1.1 MHz for the NCP3170B due to device variation. Light Load Operation Light load operation is generally a load that is 1mA to 300 mA where a load is in standby mode and requires very little power ...
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... ON Semiconductor has a Microsoft Excel® based design tool available online under the design tools section of the NCP3170 product page. The tool allows you to capture your design point and optimize the performance of your regulator based on your design criteria. ...
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The buck converter produces input voltage (V that are LC filtered to produce a lower DC output voltage (V ). The output voltage can be changed by modifying OUT the on time relative to the switching period (T) or switching ...
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... In contrast, smaller values of inductance increase the regulator’s maximum achievable slew rate and decrease the necessary capacitance at the expense of higher ripple current. The peak−to−peak ripple current for NCP3170 is given by the following equation ...
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... ESL important to note that the converters frequency response will change when the NCP3170 is operating in synchronous mode or non−synchronous mode due to the change in plant response from CCM to DCM. The (eq. 16) effect will be a larger transient voltage excursion when transitioning from no load to full load quickly ...
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Loss in the input capacitors can be calculated with the following equation CIN Iin CIN ESR RMS 1.34 A CIN = Input capacitance Equivalent Series ESR Resistance Iin = ...
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... Since the power stage design criteria is set by the application, the compensation network must correct the overall output to ensure stability. The NCP3170 is a current mode regulator and as such there exists a voltage loop and a current loop. The current loop causes the inductor to act like a current source which governs most of the characteristics of current mode control ...
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... NCP3170A 18 14.8 7.2 5 0.8 1.8 5 1.0 2.5 5 1.1 2.5 5 1.2 2.5 5 1.5 3.6 5 1.8 3.6 5 2.5 3.6 5 3.3 3.6 12 1.2 1.5 12 1.5 1.8 12 1.8 1.8 12 2.5 2.7 12 3.3 3.3 12 5.0 3.3 12 10.68 1.5 18 14.8 3.3 NCP3170B 5 0.8 1.0 5 1.0 1.0 5 1.1 1.0 5 1.2 1.5 5 1.5 1.5 5 1.8 1.5 5 2.5 1.8 5 3.3 1 (kW) (kW) (kW) (pF) (nF) 24 24.9 100 1 150 15 24.9 66.5 1 150 10 24.9 49.9 1 150 10 24.9 28.7 1 150 10 24 150 10 24.9 11.8 1 150 8.2 24.9 7.87 1 150 6.8 24.9 4.75 1 150 3.9 24.9 2.05 1 150 3 ...
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To compensate the converter we must first calculate the current feedback 1. 1.83 500 kHz W 1.358 ...
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... A good starting value is 24.9 kW. The NCP3170 allows the output of the DC−DC regulator to be adjusted down to 0.8 V via an external resistor divider network. The regulator will maintain 0 the feedback pin. Thus resistor divider circuit was placed across the ...
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Transconductance of amplifier y = Amplitude ratio ³ 14. 3. Compensation capacitance Output capacitance OUT F = Current mode ...
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... AC loop area reduces the noise of the circuit and improves efficiency. A ground plane is strongly recommended to connect the input capacitor, output capacitor, and PGND pin of the NCP3170. Drawing the real high power current flow lines on the recommended layout is important so the designer can see where the currents are flowing ...
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... Figure 52. Recommended Signal Layout The NCP3170 is the major source of power dissipation in the system for which the equations above detailed the loss mechanisms. The control portion of the IC power dissipation is determined by the formula below Control circuitry current draw Control power dissipation ...
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... C 1.35 1.75 0.053 0.069 D 0.33 0.51 0.013 0.020 G 1.27 BSC 0.050 BSC H 0.10 0.25 0.004 0.010 J 0.19 0.25 0.007 0.010 J K 0.40 1.27 0.016 0.050 0.25 0.50 0.010 0.020 S 5.80 6.20 0.228 0.244 mm inches ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative NCP3170/D _ ...