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LM3524DN Datasheet

Download or read online National Semiconductor LM3524DN ENHANCED PWM CONTROLLER, 3524, DIP pdf datasheet.
Also see for LM3524DN: Datasheet #2 (19 pages)

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Regulating Pulse Width Modulator
General Description
The LM3524D family is an improved version of the industry
standard LM3524. It has improved specifications and addi-
tional features yet is pin for pin compatible with existing 3524
families. New features reduce the need for additional exter-
nal circuitry often required in the original version.
The LM3524D has a
1% precision 5V reference. The cur-
rent carrying capability of the output drive transistors has
been raised to 200 mA while reducing V
breakdown to 60V. The common mode voltage range of
the error-amp has been raised to 5.5V to eliminate the need
for a resistive divider from the 5V reference.
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. duty cycle per
output has been improved to 44% compared to 35% max.
duty cycle in other 3524s.
In addition, the LM3524D can now be synchronized exter-
nally, through pin 3. Also a latch has been added to insure
Connection Diagram
© 2005 National Semiconductor Corporation
one pulse per period even in noisy environments. The
LM3524D includes double pulse suppression logic that in-
sures when a shut-down condition is removed the state of
the T-flip-flop will change only after the first clock pulse has
arrived. This feature prevents the same output from being
pulsed twice in a row, thus reducing the possibility of core
saturation in push-pull designs.
and increasing
n Fully interchangeable with standard LM3524 family
1% precision 5V reference with thermal shut-down
n Output current to 200 mA DC
n 60V output capability
n Wide common mode input range for error-amp
n One pulse per period (noise suppression)
n Improved max. duty cycle at high frequencies
n Double pulse suppression
n Synchronize through pin 3
Top View
Order Number LM2524DN or LM3524DN
See NS Package Number N16E
Order Number LM3524DM
See NS Package Number M16A
March 2005
Specifications of National Semiconductor LM3524DN
Base Number:
Controller Type:
Digital Ic Case Style:
No. Of Pins:
Operating Temperature Max:
Operating Temperature Range:
0°C To +125°C
Power Dissipation Pd:
Rohs Compliant:
No SVHC (15-Dec-2010)

Summary of Contents

Page 1

... Wide common mode input range for error-amp n One pulse per period (noise suppression) n Improved max. duty cycle at high frequencies n Double pulse suppression n Synchronize through pin 3 00865002 Top View Order Number LM2524DN or LM3524DN See NS Package Number N16E Order Number LM3524DM See NS Package Number M16A DS008650 March 2005 ...

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Block Diagram 2 00865001 ...

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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. Supply Voltage Collector Supply Voltage (LM2524D) (LM3524D) Output Current DC (each) Oscillator Charging Current (Pin 7) Electrical Characteristics (Note 1) Symbol Parameter REFERENCE SECTION ...

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Electrical Characteristics (Note 1) Symbol Parameter Sawtooth Valley R 5.6k Voltage ERROR-AMP SECTION V Input Offset Voltage I Input Bias Current I Input Offset Current I Compensation V ...

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Electrical Characteristics (Note 1) Symbol Parameter TC-V Sense Voltage T.C. sense Common Mode Voltage Range V − SHUT DOWN SECTION V High Input V SD (Pin 2) Voltage 150 mV I High Input I SD (pin 10) Current ...

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Typical Performance Characteristics Switching Transistor Peak Output Current vs Temperature Maximum & Minimum Duty Cycle Threshold Voltage Output Transistor Emitter Voltage Maximum Average Power Dissipation (N, M Packages) 00865028 00865030 Reference Transistor Peak Output Current 00865032 6 00865029 Output ...

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Typical Performance Characteristics Standby Current vs Voltage Current Limit Sense Voltage Test Circuit (Continued) 00865034 00865036 7 Standby Current vs Temperature 00865035 00865004 ...

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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. ...

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Functional Description The output of the amplifier, or input to the pulse width modu- lator, can be overridden easily as its output impedance MΩ). For this reason a DC voltage can be very high (Z O applied ...

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Typical Applications FIGURE 7. Positive Regulator, Step-Up Basic Configuration (I FIGURE 8. Positive Regulator, Step-Up Boosted Current Configuration 00865011 80 mA) IN(MAX) 00865012 10 ...

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Typical Applications (Continued) FIGURE 9. Positive Regulator, Step-Down Basic Configuration (I 00865013 80 mA) IN(MAX) 11 ...

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Typical Applications FIGURE 10. Positive Regulator, Step-Down Boosted Current Configuration (Continued) FIGURE 11. Boosted Current Polarity Inverter 12 00865014 00865015 ...

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Typical Applications (Continued) 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 ...

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Typical Applications where Henrys f is switching frequency in Hz Also, see LM1578 data sheet for graphical methods of in- ductor selection. CALCULATING OUTPUT FILTER CAPACITOR C Figure 13 shows L1s current with respect to Q1s t ...

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Typical Applications (Continued) Mounted to Staver Heatsink No. V5- BD344 Q2 2N5023 > turns No. 22 wire on Ferroxcube No. K300502 Torroid core. FIGURE 15. 5V, 1 Amp Step-Down Switching Regulator 15 00865020 ...

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Typical Applications 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 (Continued) TABLE 1. Conditions V 10V ...

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Typical Applications (Continued) THE STEP-UP SWITCHING REGULATOR Figure 18 shows the basic circuit for a step-up switching regulator. In this circuit Q1 is used as a switch to alternately apply V across inductor L1. During the time and ...

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Typical Applications This equation shows that the input, or inductor, current is larger than the output current by the factor ( Since this factor is the same as the relation between can also be ...

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Typical Applications (Continued) In calculating the output capacitor C it can be seen that C o supplies I during t . The voltage change time will be some V V or the output ripple of ...

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Typical Applications > turns No. 24 wire on Ferroxcube No. K300502 Toroid core. FIGURE 21. Replacing R3/R4 Divider in Figure 20 with Reference Circuit Improves Line Regulation FIGURE 22. Polarity Inverter Provides Auxiliary 15V Unregulated Output from ...

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Physical Dimensions inches (millimeters) unless otherwise noted Molded Surface-Mount Package (M) Order Number LM3524DM NS Package Number M16A 21 ...

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... English Français Tel: 33 ( 8790 Molded Dual-In-Line Package (N) Order Number LM2524DN or LM3524DN NS Package Number N16E 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system affect its safety or effectiveness ...

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