LM3495EVAL National Semiconductor, LM3495EVAL Datasheet
LM3495EVAL
Specifications of LM3495EVAL
Related parts for LM3495EVAL
LM3495EVAL Summary of contents
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... Internal soft start and the ability to track the output of another supply make the LM3495 ver- satile and efficient. Typical Application © 2007 National Semiconductor Corporation Features ■ Input voltage from 2.9V to 18V ■ ...
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Connection Diagram Ordering Information Part Number LM3495MTC LM3495MTCX Pin Descriptions BOOST (Pin 1): Supply rail for the high-side FET gate drive. The voltage should be at least one gate threshold above the regulator input voltage to properly turn on the ...
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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, ILIM SW/CSH (Note 5) BOOST, HG BOOST TRACK, FREQ, FPWM, VLIN5, SNS, LG, CSL Electrical Characteristics over the full Operating Junction Temperature (T statistical correlation. Typical values represent the most likely parametric norm at T purposes only ...
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Symbol Parameter OSCILLATOR f PWM Frequency SW V Threshold for SYNC on FREQ Pin SYNC-HI V Threshold for SYNC on FREQ Pin SYNC- Time During Skip Mode ON-SKIP t Adaptive Maximum On-time Limit ON-MAX t Minimum Off-time OFF-MIN ...
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Typical Performance Characteristics V = 12V unless specified 25°C unless specified Reference Voltage vs Temperature VLIN5 Voltage vs Temperature Switching Frequency vs Temperature 20169903 Error Amplifier Transconductance vs Temperature 20169905 5 20169904 20169906 www.national.com ...
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VLIN5 Voltage vs VIN Efficiency in FPWM Mode V = 1.0V 0. BOM in Table 1 Load Transient Response V = 3.3V BOM in Table 2 www.national.com 20169908 20169909 = 2.2V ...
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Soft-Start in SKIP Mode V = 12V 1.0V BOM in Table 1 20169915 Soft-Start in FPWM Mode V = 12V 1.0V BOM in Table ...
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Shutdown V = 12V 1.0V BOM in Table SYNC Transition Clock Starts on Logic Low BOM in Table 1 SYNC to FA Transition Clock Ends on Logic Low BOM in Table 1 ...
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Tracking With Equal Soft Start Time V = 12V 1.0V, No Load IN O BOM in Table 1 20169927 Tracking With Equal Slew Rate V = 12V 1.0V, No Load IN O BOM in Table 1 ...
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Typical Application Circuit www.national.com 10 20169977 ...
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Block Diagram 11 20169928 www.national.com ...
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Applications Information THEORY OF OPERATION The LM3495 is an advanced, current mode PWM syn- chronous controller. Unlike traditional peak current mode con- trollers which sense the current while the high-side FET is on, the LM3495 senses current while the low-side ...
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In this case, the tracking resistors can be determined based on the following equation: Again, a value of 10 kΩ recommended for R example case and V OUT1 ...
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Noise or a short burst of clock pulses can result in off times as long as 7.5 µs for the high-side FET if they occur while the internal synchro- nization circuits are adjusting. FIGURE ...
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FIGURE 6. Current Limit Sense Resistor When using a dedicated current limit sensing resistor, the equation governing the low-side current limit becomes: MAXIMUM CURRENT SENSE In order to keep the low-side current sense amplifier within its linear range, the peak ...
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Design Considerations The most common circuit controlled by the LM3495 is a non- isolated, synchronous buck regulator. The buck regulator steps down the input voltage and has a duty cycle, D, of: The following is a design procedure for selecting ...
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By calculating in terms of milliohms and kilohertz the induc- tance value will come out in micro henries. For this design: Whichever equation gives the higher value for inductance is the one which should be followed. The second criterion for ...
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Information section the value used for R be 3.32 kΩ 1%. CONTROL LOOP COMPENSATION The LM3495 uses emulated peak current-mode PWM control to correct changes in output voltage due to line and load tran- sients. This unique architecture combines ...
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FIGURE 8. Power Stage Gain and Phase The low frequency pole and higher frequency pole cause a roll-off in the gain of -20 dB/decade at lower frequency that increases to -40 dB/decade at higher frequency. The effect of the ESR ...
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FIGURE 9. Error Amplifier Gain and Phase The total control loop transfer function equal to the pow- er stage transfer function multiplied by the error amplifier transfer function. The bandwidth and phase margin can be read graphically from ...
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R Loss (if used) SNS (( SNS O Not used in this example. Input Capacitor Loss This term represents the loss as input ripple current passes through the ESR of the ...
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Table 1: Bill of Materials for 6.0V to 18.0V Input, 1.0V Output, 7A, 500 kHz ID Part Number U1 LM3495 Q1 Si4894DY Q2 Si4442DY D1 MBR0530 L1 RLF12545T-2R7N8R7 C ,C C3225X5R1E106M IN1 IN2 C 6TPD470M O1 C C2012X7R1E105M F C ...
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Table 2: Bill of Materials for 3.0V to 6.0V Input, 2.2V Output, 7A, 500 kHz ID Part Number U1 LM3495 Q1 Si4866DY Q2 Si4838DY D1 MBR0530 L1 MSS1260–102NX C3225X5R1A226M IN1 IN2 C 6TPD470M O1 C C2012X7R1E105M F ...
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Table 3: Bill of Materials for Typical Application Circuit ID Part Number U1 LM3495 Q1 HAT2198R Q2 HAT2165H D1 MBR0530 L1 RLF12560T-1R0N140 C C3225X5R1E226M C3225X5R0J107M C2012X7R1E105M F C C2012X7R1C225M ...
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Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Plastic Order Number LM3495MTC/MTCX NS Package Number MTC16 25 www.national.com ...
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