LM3524D Datasheet

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LM2524D,LM3524D
LM2524D/LM3524D Regulating Pulse Width Modulator
Literature Number: SNVS766D
Specifications of TI (Texas Instruments) LM3524D
Approx. Price (us$):
0.53 | 1ku
Frequency(min)(khz):
0.001
Iout(max)(a):
0.2
Pin/package:
16PDIP, 16SOIC
Regulated Outputs(#):
1
Switching Frequency(max)(khz):
550
Topology:
Buck, Boost, Flyback, Push-pull
Vin(max)(v):
40
Vin(min)(v):
5

Summary of Contents

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... LM2524D,LM3524D LM2524D/LM3524D Regulating Pulse Width Modulator Literature Number: SNVS766D ...

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... In the LM3524D the circuit bias line has been isolated from the shut-down pin. This prevents the oscillator pulse ampli- tude and frequency from being disturbed by shut-down. Also at high frequencies ( 300 kHz) the max ...

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Block Diagram www.national.com 2 865001 ...

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... 40V 0 5.6k 0.01 μ 0.01 μF 0.5 1 0.01 μF 3.4 3 40°C to 125°C 0°C to 125°C 65°C to 150°C LM3524D Design Tested Design Limit Typ Limit Limit (Note 4) (Note 3) (Note 4) 4.80 4.75 5 5.25 5. 200 100 ...

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... 0.01 μF] 5.6k 0.001 μ 3.5 1 180 V (Pin 1) 200 220 0.2 4 LM3524D Design Tested Design Limit Typ Limit Limit (Note 4) (Note 3) (Note 4) 0 125 125 95 ...

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... Note 1: Unless otherwise stated, these specifications apply for T 85°C and LM3524D is 0°C to 70° 20V and f IN Note 2: For operation at elevated temperatures, devices in the N package must be derated based on a thermal resistance of 86°C/W, junction to ambient. Devices in the M package must be derated at 125°C/W, junction to ambient. ...

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Typical Performance Characteristics Switching Transistor Peak Output Current vs Temperature Maximum & Minimum Duty Cycle Threshold Voltage Output Transistor Emitter Voltage www.national.com Maximum Average Power Dissipation (N, M Packages) 865028 Output Transistor Saturation Voltage 865030 Reference Transistor Peak Output Current ...

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Standby Current vs Voltage Current Limit Sense Voltage Test Circuit 865034 865036 7 Standby Current vs Temperature 865035 865004 www.national.com ...

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... Functional Description INTERNAL VOLTAGE REGULATOR The LM3524D has an on-chip 5V, 50 mA, short circuit pro- tected voltage regulator. This voltage regulator provides a supply for all internal circuitry of the device and can be used as an external reference. For input voltages of less than 8V the 5V output should be shorted to pin 15 which disables the 5V regulator ...

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... OUTPUT STAGES The outputs of the LM3524D are NPN transistors, capable of a maximum current of 200 mA. These transistors are driven 180° out of phase and have non-committed open collectors and emitters as shown in Figure 6. ...

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Typical Applications FIGURE 7. Positive Regulator, Step-Up Basic Configuration (I FIGURE 8. Positive Regulator, Step-Up Boosted Current Configuration www.national.com 865011 80 mA) IN(MAX) 10 865012 ...

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FIGURE 9. Positive Regulator, Step-Down Basic Configuration (I 865013 80 mA) IN(MAX) 11 www.national.com ...

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FIGURE 10. Positive Regulator, Step-Down Boosted Current Configuration www.national.com FIGURE 11. Boosted Current Polarity Inverter 12 865014 865015 ...

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... BASIC SWITCHING REGULATOR THEORY AND APPLICATIONS The basic circuit of a step-down switching regulator circuit is shown in Figure 12, along with a practical circuit design using the LM3524D in Figure 15. FIGURE 12. Basic Step-Down Switching Regulator FIGURE 13. Relation of Switch Timing to Inductor Current in Step-Down Regulator , and settling ΔI Δ ...

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... LM3524D, is illustrated in Figure 15. Transistors Q1 and Q2 have been added to boost the output to 1A. The 5V reg- ulator of the LM3524D has been divided in half to bias the error amplifier's non-inverting input to within its common- mode range. Since each output transistor is on for half the period, actually 45%, they have been paralleled to allow longer possible duty cycle 90% ...

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Staver Heatsink No. V5- BD344 Q2 2N5023 L1 >40 turns No. 22 wire on Ferroxcube No. K300502 Torroid core. FIGURE 15. 5V, 1 Amp Step-Down Switching Regulator 15 865020 www.national.com ...

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Parameter Output Voltage Switching Frequency Short Circuit Current Limit Load Regulation Line Regulation Efficiency Output Ripple FIGURE 16. 5V, 1 Amp Switching Regulator, Foil Side www.national.com TABLE 1. Conditions V 10V 10V, ...

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THE STEP-UP SWITCHING REGULATOR Figure 18 shows the basic circuit for a step-up switching reg- ulator. In this circuit Q1 is used as a switch to alternately apply V across inductor L1. During the time energy is drawn ...

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... It should also be noted that this circuit has no supply re- jection. By adding a reference voltage at the non-inverting input to the error amplifier, see Figure 21, the input voltage variations are rejected. The LM3524D can also be used in inductorless switching regulators. Figure 22 shows a polarity inverter which if con- nected to Figure 20 provides a 15V unregulated output. 18 ...

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L1 > 25 turns No. 24 wire on Ferroxcube No. K300502 Toroid core. FIGURE 20. 15V, 0.5A Step-Up Switching Regulator FIGURE 21. Replacing R3/R4 Divider in Figure 20 with Reference Circuit Improves Line Regulation FIGURE 22. Polarity Inverter Provides ...

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... Physical Dimensions www.national.com inches (millimeters) unless otherwise noted Molded Surface-Mount Package (M) Order Number LM3524DM NS Package Number M16A 20 ...

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... Molded Dual-In-Line Package (N) Order Number LM2524DN or LM3524DN NS Package Number N16E 21 www.national.com ...

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For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock Conditioners www.national.com/timing Data Converters www.national.com/adc Displays www.national.com/displays Ethernet www.national.com/ethernet Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators ...

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... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...

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