Electronic Components Datasheet Search |
|
LT1931 Datasheet(PDF) 10 Page - Linear Technology |
|
LT1931 Datasheet(HTML) 10 Page - Linear Technology |
10 / 28 page LT3580 10 3580fg APPLICATIONS INFORMATION these materials retain their capacitance over wider voltage and temperature ranges. A 4.7μF to 20μF output capaci- tor is sufficient for most applications, but systems with very low output currents may need only a 1μF or 2.2μF output capacitor. Always use a capacitor with a sufficient voltage rating. Many capacitors rated at 2.2μF to 20μF, particularly 0805 or 0603 case sizes, have greatly reduced capacitance at the desired output voltage. Solid tantalum or OS-CON capacitors can be used, but they will occupy more board area than a ceramic and will have a higher ESR with greater output ripple. Ceramic capacitors also make a good choice for the input decoupling capacitor, which should be placed as closely as possible to the LT3580. A 2.2μF to 4.7μF input capacitor is sufficient for most applications. Table 2 shows a list of several ceramic capacitor manufac- turers. Consult the manufacturers for detailed information on their entire selection of ceramic parts. Table 2. Ceramic Capacitor Manufacturers Kemet www.kemet.com Murata www.murata.com Taiyo Yuden www.t-yuden.com Compensation—Adjustment To compensate the feedback loop of the LT3580, a series resistor-capacitor network in parallel with a single capacitor should be connected from the VC pin to GND. For most applications, the series capacitor should be in the range of 470pF to 2.2nF with 1nF being a good starting value. The parallel capacitor should range in value from 10pF to 100pF with 47pF a good starting value. The compensation resistor, RC, is usually in the range of 5k to 50k. A good technique to compensate a new application is to use a 100k Ω potentiometer in place of series resistor RC. With the series capacitor and parallel capacitor at 1nF and 47pF respectively, adjust the potentiometer while observing the transient response and the optimum value for RC can be found. Figures 3a to 3c illustrate this process for the circuit of Figure 14 with a load current stepped between 400mA and 500mA. Figure 3a shows the transient response with RC equal to 1k. The phase margin is poor, as evidenced by the excessive ringing in the output voltage and inductor current. In Figure 3b, the value of RC is increased to 3k, which results in a more damped response. Figure 3c shows the results when RC is increased further to 10k. The transient response is nicely damped and the compensation procedure is complete. Figure 3a. Transient Response Shows Excessive Ringing Figure 3b. Transient Response Is Better Figure 3c. Transient Response Is Well Damped VOUT 200mV/DIV AC COUPLED IL 0.5A/DIV 200μs/DIV RC = 1k 3580 F03a VOUT 200mV/DIV AC COUPLED IL 0.5A/DIV 200μs/DIV RC = 3k 3580 F03b VOUT 200mV/DIV AC COUPLED IL 0.5A/DIV 200μs/DIV RC = 10k 3580 F03c |
Similar Part No. - LT1931 |
|
Similar Description - LT1931 |
|
|
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 |