 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LT124XMJ8 Datasheet(PDF) 8 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LT124XMJ8 Datasheet(HTML) 8 Page - Linear Technology |
|
|
8 / 16 page  LT1241 Series 8 for various values of RT and CT appear in the Typical Performance Characteristics section. Frequency and deadtime can also be calculated using the following formulas: Oscillator Rise Time: tr = 0.583 • RC S APPLICATI I FOR ATIO Oscillator Discharge Time: Oscillator Frequency: Oscillator Period: TOSC = tr + td frequency for LT1241, LT1244 and LT1245. The oscillator of LT1241 series devices will run at frequencies up to 1MHz, allowing 500kHz output switching frequencies for all devices. Error Amplifier The LT1241 series of devices contain a fully compensated error amplifier with a DC gain of 90dB and a unity-gain frequency of 1MHz. Phase margin at unity-gain is 80 °. The noninverting input is internally committed to a 2.5V refer- ence point derived from the 5V reference of Pin 8. The inverting input (Pin 2) and the output (Pin 1) are made available to the user. The output voltage in a regulator circuit is normally fed back to the inverting input of the error amplifier through a resistive divider. The output of the error amplifier is made available for external loop compensation. The output current of the error amplifier is limited to approximately 0.8mA sourcing and approximately 6mA sinking. In a current mode PWM the peak switch current is a function of the output voltage of the error amplifier. In the LT1241 series devices the output of the error amplifier is offset by two diodes (1.4V at 25 °C), divided by a factor of three, and fed to the inverting input of the current sense comparator. For error amplifier output voltages less than 1.4V the duty cycle of the output stage will be zero. The maximum offset that can appear at the current sense input is limited by a 1V clamp. This occurs when the error amplifier output reaches 4.4V at 25 °C. The output of the error amplifier can be clamped below 4.4V in order to reduce the maximum voltage allowed across the current sensing resistor to less than 1V. The supply current will increase by the value of the output source current when the output voltage of the error amplifier is clamped. t RC R d = • () − 346 0 0164 11 73 . .. f T OSC OSC = 1 Maximum Duty Cycle: LT1241, LT1244, LT1245 D t T Tt T MAX r OSC OSC d OSC == − 22 LT1242, LT1243 The above formulas will give values that will be accurate to approximately ±5%, at the oscillator, over the full operating frequency range. This is due to the fact that the oscillator trip levels are constant versus frequency and the discharge current and initial oscillator frequency are trimmed. Some fine adjustment may be required to achieve more accurate results. Once the final RT/CTcombination is selected the oscillator characteristics will be repeatable from device to device. Note that there will be some slight differences between maximum duty cycle at the oscillator and maximum duty cycle at the output due to the finite rise and fall times of the output. The output switching frequency will be equal to the oscillator frequency for LT1242 and LT1243. The output switching frequency will be equal to one-half the oscillator D t T Tt T MAX r OSC OSC d OSC == − |
Similar Part No. - LT124XMJ8 |
|
Similar Description - LT124XMJ8 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
