lm5008asdcx National Semiconductor Corporation, lm5008asdcx Datasheet
lm5008asdcx
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lm5008asdcx Summary of contents
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... Other fea- tures include: Thermal Shutdown, V Gate drive under-voltage lockout, Max Duty Cycle limiter, and a pre-charge switch. Typical Application, Basic Step-Down Regulator © 2009 National Semiconductor Corporation LM5008A Features ■ Operating input voltage range 95V ■ ...
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... Connection Diagrams Top View 8-Lead LLP Ordering Information Order Number LM5008AMM LM5008AMMX LM5008ASDC LM5008ASDCX Pin Descriptions Pin Name Description 1 SW Switching Node 2 BST Boost Pin (Boot–strap capacitor input) 3 RCL Current Limit OFF time set pin 4 RTN Ground pin 5 FB Feedback input from Regulated ...
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Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications GND IN BST to GND SW to GND (Steady State) ESD Rating (Note 5) Human Body Model ...
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Symbol Parameter Minimum Off Time Minimum Off Timer Regulation and OV Comparators FB Reference Threshold FB Over-Voltage Threshold FB Bias Current Thermal Shutdown Tsd Thermal Shutdown Temp. Thermal Shutdown Hysteresis Thermal Resistance θ Junction to Ambient JA Note 1: Absolute ...
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Typical Performance Characteristics Efficiency vs. Load Current and V (Circuit of Figure 4) ON-Time vs Input Voltage and R Maximum Frequency vs 30074924 Current Limit Off-Time vs 30074925 and V I OUT IN CC 30074926 5 ...
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Block Diagram Functional Description The LM5008A Step Down Switching Regulator features all the functions needed to implement a low cost, efficient, Buck bias power converter. This high voltage regulator contains a 100 V N-Channel Buck Switch, is easy to implement ...
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The LM5008A regulates the output voltage based on ripple voltage at the feedback input, requiring a minimum amount of ESR for the output capacitor C2. A minimum of 25mV to 50mV of ripple voltage at the feedback pin (FB) is ...
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Regulation Comparator The feedback voltage compared to an internal 2.5V reference. In normal operation (the output voltage is regulat- ed), an on-time period is initiated when the voltage at FB falls below 2.5V. The buck switch will ...
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FIGURE 3. Shutdown Implementation Current Limit The LM5008A contains an intelligent current limit OFF timer. If the current in the Buck switch exceeds 0.51A the present cycle is immediately terminated, and a non-resetable OFF timer is initiated. The length of ...
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LM5008A’s current limit threshold (610 mA) with- out saturating, since the current limit is reached during start- up. The ...
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Bill of Materials Item Description C1 Ceramic Capacitor C2 Ceramic Capacitor C3 Ceramic Capacitor C4 Ceramic Capacitor C5 Ceramic Capacitor D1 Schottky Power Diode L1 Power Inductor R Resistor FB2 R Resistor FB1 R3 Resistor R Resistor T R Resistor ...
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LOW OUTPUT RIPPLE CONFIGURATIONS For applications where low output ripple is required, the fol- lowing options can be used to reduce or nearly eliminate the ripple. a) Reduced ripple configuration: In Figure 7, Cff is added across R to AC-couple ...
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FIGURE 7. Reduced Ripple Configuration b) Minimum ripple configuration: If the application requires a lower value of ripple (<10 mVp-p), the circuit of Figure 8 can be used removed, and the resulting output ripple volt- age is determined ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead MSOP Package NS Package Number MUA08A 8-Lead LLP Package NS Package Number SDC08B 14 ...
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