Moteur de recherche de fiches techniques de composants électroniques |
|
LM2524DN Fiches technique(PDF) 9 Page - National Semiconductor (TI) |
|
|
LM2524DN Fiches technique(HTML) 9 Page - National Semiconductor (TI) |
9 / 22 page Functional Description (Continued) The output of the amplifier, or input to the pulse width modu- lator, can be overridden easily as its output impedance is very high (Z O . 5M Ω). For this reason a DC voltage can be applied to pin 9 which will override the error amplifier and force a particular duty cycle to the outputs. An example of this could be a non-regulating motor speed control where a variable voltage was applied to pin 9 to control motor speed. A graph of the output duty cycle vs the voltage on pin 9 is shown in Figure 5. The duty cycle is calculated as the percentage ratio of each output’s ON-time to the oscillator period. Paralleling the out- puts doubles the observed duty cycle. The amplifier’s inputs have a common-mode input range of 1.5V–5.5V. The on board regulator is useful for biasing the inputs to within this range. CURRENT LIMITING The function of the current limit amplifier is to override the error amplifier’s output and take control of the pulse width. The output duty cycle drops to about 25% when a current limit sense voltage of 200 mV is applied between the +C L and −C Lsense terminals. Increasing the sense voltage ap- proximately 5% results in a 0% output duty cycle. Care should be taken to ensure the −0.7V to +1.0V input common- mode range is not exceeded. In most applications, the current limit sense voltage is pro- duced by a current through a sense resistor. The accuracy of this measurement is limited by the accuracy of the sense resistor, and by a small offset current, typically 100 µA, flowing from +CL to −CL. 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. 00865008 FIGURE 5. 00865009 FIGURE 6. www.national.com 9 |
Numéro de pièce similaire - LM2524DN |
|
Description similaire - LM2524DN |
|
|
Lien URL |
Politique de confidentialité |
ALLDATASHEET.FR |
ALLDATASHEET vous a-t-il été utile ? [ DONATE ] |
À propos de Alldatasheet | Publicité | Contactez-nous | Politique de confidentialité | Echange de liens | Fabricants All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |