LM25576EVAL National Semiconductor, LM25576EVAL Datasheet
LM25576EVAL
Specifications of LM25576EVAL
Related parts for LM25576EVAL
LM25576EVAL Summary of contents
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... TSSOP-20 package featuring an exposed die attach pad for thermal dissipation. The LM25576 is sup- ported by the full suite of WEBENCH Simplified Application Schematic WEBENCH ® registered trademark of National Semiconductor Corporation. © 2009 National Semiconductor Corporation LM25576/LM25576Q Features ■ LM25576Q is an Automotive Grade product that is AEC- Q100 grade 1 qualified (− ...
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Connection Diagram Ordering Information Order Number Package Type LM25576MH Exposed Pad TSSOP-20 MXA20A LM25576MHX Exposed Pad TSSOP-20 MXA20A LM25576QMH Exposed Pad TSSOP-20 MXA20A LM25576QMHX Exposed Pad TSSOP-20 MXA20A * Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for ...
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Pin Descriptions Pin(s) Name 1 VCC Output of the bias regulator 2 SD Shutdown or UVLO input 3, 4 Vin Input supply voltage 5 SYNC Oscillator synchronization input or output The internal oscillator can be synchronized to an external 6 ...
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Pin(s) Name 20 BST Boost input for bootstrap capacitor NA EP Exposed Pad www.national.com Description An external capacitor is required between the BST and the SW pins. A 0.022µF ceramic capacitor is recommended. The capacitor is charged from Vcc via ...
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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 PRE to GND SW to GND (Steady State) BST SD GND CC Electrical Characteristics apply over full Operating Junction Temperature range. V Symbol ...
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Symbol Parameter RAMP GENERATOR Ramp Current 1 Ramp Current 2 PWM COMPARATOR Forced Off-time Min On-time COMP to PWM Comparator Offset ERROR AMPLIFIER Feedback Voltage FB Bias Current DC Gain COMP Sink / Source Current Unity Gain Bandwidth DIODE SENSE ...
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Soft Start Current vs Temperature 20208722 7kΩ L 20208724 Demoboard Efficiency vs I and V OUT IN 20208726 12V IN Error Amplifier Gain/Phase A = 101 ...
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Typical Application Circuit and Block Diagram www.national.com 8 ...
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Detailed Operating Description The LM25576 switching regulator features all of the functions necessary to implement an efficient high voltage buck regu- lator using a minimum of external components. This easy to use regulator integrates a 42V N-Channel buck switch with ...
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Shutdown / Standby The LM25576 contains a dual level Shutdown (SD) circuit. When the SD pin voltage is below 0.7V, the regulator low current shutdown mode. When the SD pin voltage is greater than 0.7V but less ...
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FIGURE 5. Simplified Oscillator Block Diagram and SYNC I/O Circuit Error Amplifier and PWM Comparator The internal high gain error amplifier generates an error signal proportional to the difference between the regulated output voltage and an internal precision reference (1.225V). ...
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The sample & hold DC level illustrated in Figure 6 is derived from a measurement of the re-circulating Schottky diode an- ode current. The re-circulating diode anode should be con- nected to the IS pin. The diode current flows through ...
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Maximum Duty Cycle / Input Drop- out Voltage There is a forced off-time of 500ns implemented each cycle to guarantee sufficient time for the diode current to be sam- pled. This forced off-time limits the maximum duty cycle of the ...
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Application Information EXTERNAL COMPONENTS The procedure for calculating the external components is il- lustrated with the following design example. The Bill of Mate- rials for this design is listed in Table 1. The circuit shown in Figure 1 is configured ...
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RMS current rating and minimum ripple voltage. A good approximation for the re- quired ripple current rating necessary is I Quality ceramic capacitors with a low ESR should be selected for the input filter. To ...
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R4C5). The error amplifier zero cancels the modulator pole leaving a single pole response at the crossover frequen the loop gain. A single pole response at the crossover frequency yields a very stable loop with 90 ...
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FIGURE 12. VCC Bias from VOUT for 8V < VOUT < 14V FIGURE 13. VCC Bias with Additional Winding on the Output Inductor 17 20208718 20208719 www.national.com ...
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PCB LAYOUT AND THERMAL CONSIDERATIONS The circuit in Figure 13 serves as both a block diagram of the LM25576 and a typical application board schematic for the LM25576 buck regulator there are two loops where cur- rents are ...
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... DIODE, 60V, CENTRAL DIODE, 100V, IR (D1-ALT) INDUCTOR, COOPER NOT USED NOT USED RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR REGULATOR, NATIONAL SEMICONDUCTOR 19 VALUE 2.2µ, 100V 2.2µ, 100V 330p, 100V 0.01µ, 100V 0.01µ, 100V 0.022µ, 100V 0.47µ, 16V 22µ ...
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PCB Layout www.national.com Component Side Solder Side Silkscreen 20 20208729 20208730 20208731 ...
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Typical Schematic for High Frequency (1MHz) Application Typical Schematic for Buck/Boost (Inverting) Application Schematic 3.3V, 3A, 1MHz 21 20208740 20208742 www.national.com ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 20-Lead TSSOP Package NS Package Number MXA20A 22 ...
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Notes 23 www.national.com ...
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