 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
TK71150 Datasheet(PDF) 15 Page - TOKO, Inc |
|
||||||||||||||||||||||||||||||
TK71150 Datasheet(HTML) 15 Page - TOKO, Inc |
|
|
15 / 16 page  July 2000 TOKO, Inc. Page 15 TK711xx TERMS AND DEFINITIONS (CONT.) The range of usable currents can also be found from the graph below. Procedure: 1) Find P D 2) P D1 is taken to be PD x (~ 0.8 - 0.9) 3) Plot P D1 against 25 °C 4) Connect P D1 to the point corresponding to the 150 °C with a straight line. 5) In design, take a vertical line from the maximum operating temperature (e.g., 75 °C) to the derating curve. 6) Read off the value of P D against the point at which the vertical line intersects the derating curve. This is taken as the maximum power dissipation, D PD. The maximum operating current is: I OUT = (DPD / (VIN(MAX) - VOUT) INPUT/OUTPUT DECOUPLING CAPACITOR CONSIDERATIONS Voltage regulators require input and output decoupling capacitors. The required value of these capacitors vary with application. Capacitors made by different manufacturers can have different characteristics, particularly with regard to high frequencies and Equivalent Series Resistance (ESR) over temperature. The type of capacitor is also important. For example, a 4.7 µF aluminum electrolytic may be required for a certain application. If a tantalum capacitor is used, a lower value of 2.2 µF would be adequate. It is important to consider the temperature characteristics of the decoupling capacitors. While Toko regulators are designed to operate as low as -40 °C, many capacitors will not operate properly at this temperature. The capacitance of aluminum electrolytic capacitors may decrease to 0 at low temperatures. This may cause oscillation on the output of the regulator since some capacitance is required to guarantee stability. Thus, it is important to consider the characteristics of the capacitor over temperature when selecting decoupling capacitors. The ESR is another important parameter. The ESR will increase with temperature but low ESR capacitors are often larger and more costly. In general, tantalum capacitors offer lower ESR than aluminum electrolytic, but new low ESR aluminum electrolytic capacitors are now available from several manufacturers. Usually a bench test is sufficient to determine the minimum capacitance required for a particular application. After taking thermal characteristics and tolerance into account, the minimum capacitance value should be approximately two times this value. The recommended minimum capacitance for the TK711xxN is 2.1 µF for a tantalum capacitor or 3.3 µF for an aluminum electrolytic. Please note that linear regulators with a low dropout voltage have high internal loop gains which require care in guarding against oscillation caused by insufficient decoupling capacitance. The use of high quality decoupling capacitors suited for your application will guarantee proper operation of the circuit. Pay attention to temperature characteristics of the capacitor, especially the increase of ESR and decrease of capacitance in low temperatures. Oscillation, reduction of ripple rejection and increased noise may occur in some cases if the proper capacitor is not used. An output capacitor more than 1.0 µF is required to maintain stability. The standard test condition is 3.3 µF (T A = 25 °C). PD DPD 25 50 75 150 (mW) TA (°C) 3 6 5 4 0 50 100 TA (°C) 150 0 600 1000 200 400 800 MOUNTED TO-92 POWER DISSIPATION CURVE APPLICATION INFORMATION |
Similar Part No. - TK71150 |
|
Similar Description - TK71150 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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
