LM2640MTC-ADJ/NOPB National Semiconductor, LM2640MTC-ADJ/NOPB Datasheet
LM2640MTC-ADJ/NOPB
Specifications of LM2640MTC-ADJ/NOPB
*LM2640MTC-ADJ/NOPB
LM2640MTC-ADJ
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LM2640MTC-ADJ/NOPB Summary of contents
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... Programmable soft-start (each controller linear regulator output n Precision 2.5V reference output n 28-pin TSSOP Applications n Notebook and subnotebook computers n Wireless data terminals n Battery-powered instruments 28-Lead TSSOP (MTC) 10014801 Top View Order Number LM2640MTC-ADJ See NS Package Number MTC28 DS100148 May 2001 www.national.com ...
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Pin Description (Refer to Typical Application Circuits) Pin # Name 1 CSH2 The sense point for the positive side of the voltage across the current sense resistor (R13) placed in series with output # 2. 2 FB2 The regulated output ...
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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. IN, SW1, and SW2 FB1 and FB2 SD, ON/OFF1, ON/OFF2, 2NDFB/FPWM, SYNC, REF, SS1, SS2, COMP1, COMP2 and CSL1 LIN CSH1, CSH2, and CSL2 ...
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Electrical Characteristics Typicals and limits appearing in regular type apply for T tion temperature range for operation +125˚C. Unless otherwise specified under the Parameter or Conditions columns 10V, and ON/OFF1 ...
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... The LM2640 actively limits its junction temperature to about 150˚C. Note 4: For detailed information on soldering plastic small-outline packages, refer to the Packaging Databook available from National Semiconductor Corporation. Note 5: For testing purposes, ESD was applied using the human-body model, a 100 pF capacitor discharged through a 1.5 k Note 6: A typical is the center of characterization data taken with T Note 7: All limits are guaranteed ...
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Electrical Characteristics Note 8: Both controllers are ON but not switching. Currents entering the IC at IN, CSL1, CSH1, CSL2, and CSH2 are measured. Those entering at CSL1 and CSH1 are multiplied by 0.50 to emulate the effect of a ...
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Block Diagram 10014802 FIGURE 3. LM2640 Block Diagram 9 www.national.com ...
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Typical Performance Characteristics Efficiency vs Load Current 10014814 Efficiency vs Load Current 10014817 Efficiency vs Load Current 10014820 Efficiency vs Load Current 10014823 www.national.com Efficiency vs Load Current 10014815 Efficiency vs Load Current 10014818 Efficiency vs Load Current 10014821 Efficiency ...
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Typical Performance Characteristics REF Output Voltage 10014826 Normalized Error Amplifier Offset vs Junction Temperature 10014829 Normalized Oscillator Frequency vs. Junction Temperature 10014832 (Continued) REF Output Voltage 10014827 Error Amplifier Gm vs Junction Temperature 10014830 CH1 Skip Frequency vs Load Current ...
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Theory of Operation Basic Operation of the Current-Mode Controller The output voltage is held at a constant value by the main control loop, which is made up of the error amplifier , the current sense amplifier , and the PWM ...
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Application Information 5V LIN Output The LM2640 contains a built-in 5V/50 mA LDO regulator whose output is connected to the LIN pin. Since this is an LDO regulator, it does require an external capacitor to main- tain stability. The minimum ...
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Application Information If the output voltage does not move to within −1% of nominal in the period of 4096 counts, the device will latch OFF. To restore operation, the power must be cycled OFF to ON. Minimum Pulse Width As ...
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Application Information FIGURE 4. Typical Compensation Network The components shown will add poles and zeros to the loop gain as given by the following equations: C10 adds a pole whose frequency is given by: f (C10 ...
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Application Information FIGURE 6. Calculated Gain Plot for 3.3V/4A Application Looking at the plot, it can be seen that the unity-gain cross- over frequency f is expected to be about 25 kHz. Using this c value, the phase margin at ...
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Design Procedure (Continued) case, the manufacturer’s specified inductance value is usu- ally the maximum value, which means the actual inductance in your application will be much less. An inductor with a flatter inductance curve is preferable, since the loop characteristics ...
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... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...