LM34923EVAL/NOPB National Semiconductor, LM34923EVAL/NOPB Datasheet
LM34923EVAL/NOPB
Specifications of LM34923EVAL/NOPB
Related parts for LM34923EVAL/NOPB
LM34923EVAL/NOPB Summary of contents
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... Other features include: Thermal Shutdown, VCC Under Voltage Lock-out, Max Duty Cycle Limiter, a Pre-charge Switch, and a programmable Un- der Voltage Detector with a status flag output. Typical Application, Basic Step-Down Regulator © 2011 National Semiconductor Corporation LM34923 Features ■ Operating input voltage range 75V ■ ...
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Connection Diagram Ordering Information Order Number LM34923MM LM34923MMX Pin Descriptions Pin Name Description 1 SW Switching Node 2 BST Boost Pin 3 N/C Do not connect 4 RTN Ground pin 5 UV Input pin for the under voltage indicator 6 ...
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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. VIN RTN BST to RTN SW to RTN (Steady State) BST to VCC BST to SW VCC, UVO RTN FB, RT, to RTN Electrical Characteristics over the full Operating Junction Temperature (T statistical correlation ...
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... For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: For detailed information on soldering plastic MSOP packages, refer to the Packaging Data Book available from National Semiconductor Corporation. Note 3: All limits are guaranteed. All electrical characteristics having room temperature limits are tested during production with T limits are guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control ...
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Typical Performance Characteristics Efficiency at 300 kHz, 10V V vs vs. Externally Applied 900 kHz 200 kHz DCM 0 7.5 8.0 8.5 APPLIED VCC (V) Efficiency Comparison ...
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Current Limit Off-Time vs. V Voltage at the R Shutdown Current into V www.national.com FB 30141738 Pin T 30141740 UVO Pin Low Voltage vs. Sink Current IN 30141742 6 Maximum Switching Frequency 30141739 Operating Current into V IN 30141741 30141743 ...
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V UVLO vs. Temperature CC 30141745 V vs. Temperature CC 30141747 V Output Impedance vs. Temperature CC 30141748 Gate Drive UVLO vs. Temperature V Dropout vs. Temperature CC V Current Limit vs. Temperature CC 7 30141746 30141759 30141749 www.national.com ...
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Reference Voltage vs. Temperature Minimum Off-time vs. Temperature Current Limit Off-Time vs. Temperature www.national.com On-time vs. Temperature 30141750 Current Limit Threshold vs. Temperature 30141752 Operating Current vs. Temperature 30141760 8 30141751 30141753 30141754 ...
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Shutdown Current vs. Temperature 30141755 UV Pin Threshold vs. Temperature 30141761 RT Pin Shutdown Threshold vs. Temperature UV Hysteresis Current vs. Temperature 9 30141756 30141762 www.national.com ...
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Block Diagram Functional Description The LM34923 Step Down Switching Regulator features all the functions needed to implement a low cost, efficient, Buck bias power converter. This high voltage regulator contains N-Channel Buck Switch, is easy to implement ...
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The discon- tinuous operating frequency can be calculated as follows: where R = the load resistance L In continuous conduction mode, current flows continuously through the inductor and never ramps down to ...
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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 stays ...
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FIGURE 3. Shutdown Implementation Current Limit The LM34923 contains an intelligent current limit OFF timer. If the current in the Buck switch reaches the current limit threshold, the present cycle is immediately terminated, and a non-resetable OFF timer is triggered. ...
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The maximum allowed frequency is the lesser of the two above calculations. See the graph “Maximum Switching Fre- quency”. For this exercise, F calculates to 667 kHz, and s(max)1 F calculates to 1.28 MHz. Therefore the maximum al- s(max)2 lowed ...
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Choose the upper and lower thresholds ( example, assume the application requires the following thresholds 15V and V = 14V. Therefore V UVH UVL = 1V. The resistor values calculate to ...
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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 across R to AC-couple the ripple at V FB2 ...
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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 be used removed, and the resulting output ripple volt- age is determined by the inductor’s ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted Mini SO Molded NS Package MUB10A 18 ...
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Notes 19 www.national.com ...
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