Electronic Components Datasheet Search |
|
SG2549 Datasheet(PDF) 4 Page - Microsemi Corporation |
|
SG2549 Datasheet(HTML) 4 Page - Microsemi Corporation |
4 / 4 page Rev 1.1a Copyright © 1994 11861 Western Avenue ∞ ∞ ∞ ∞ ∞ Garden Grove, CA 92841 4 (714) 898-8121 ∞ ∞ ∞ ∞ ∞ FAX: (714) 893-2570 SG1549/SG2549/SG3549 APPLICATION NOTES (continued) FIGURE 2 — CURRENT CONTROL FOR A BUCK REGULATOR WITH CONSTANT DRIVE CURRENT FIGURE 4 — POWER BOOST AND CURRENT CONTROL WITH THE SG1627 FIGURE 3 — A PUSH-PULL CONVERTER WITH LOW-LINE EMITTER CURRENT SENSING Another method of introducing the current shutdown signal is shown in Figure 2 where the SG1524 is used to activate a constant drive current to the high-current switch, in this case an SM600. The 2N2222 forms a constant current generator when driven from the SG1524’s 5.0 volt reference through a 1K resistor. This transistor is then switched off by the LO OUTPUT transistor in the SG1549, achieving the fastest re- sponse to the output of the regulator. LOW LINE SENSING - In many types of feed-forward or push-pull converters, current protection may be provided by sensing in an emitter resistor referenced to ground on the primary side of an output trans- former. The fast-reacting SG1549 can easily sense secondary overload as reflected back to the primary and, additionally, provide protection from unbalanced transformer saturation. When using the LO CM inputs, the HI CM inputs should be shorted together. While the LO CM inputs may be connected directly across a sense resistor, R SC , a small low-pass filter as shown in Figure 3 is often required to eliminate high frequency transients. It must be remembered that the 500 Ωinput impedance at the LO CM terminals will cause the use of R1 to increase the effective threshold; however, this also offers the possibility of an easily adjustable threshold by incorporating a potenti- ometer at the input. Coupling the output signal from the SG1549 to the control chip may be done in several ways including the use of either the Compensation or Shutdown pins on the SG1524 as described earlier. Another convenient way to tie the output of the SG1549 into the PWM control in higher power applications is by using the SG1627 Dual Interface Driver and connecting the LO OUTPUT terminal of the Sg1549 directly to the two Non-Inverting inputs of the SG1627 as shown in Figure 4. And finally, keep in mind that the LO OUTPUT terminal of the SG1549 will easily drive most high-speed optical couplers should some type of isolation between current sense and shutdown control be required. Ambient Temperature Range Part No. Package Connection Diagram 8-PIN CERAMIC DIP Y - PACKAGE 8 7 6 5 2 1 3 4 — HI CM INPUT + HI CM INPUT + LO CM INPUT — LO CM INPUT CLOCK RESET +V S LO OUTPUT HI OUTPUT SG1549Y/883B -55 °C to 125°C SG1549Y/DESC -55 °C to 125°C SG1549Y -55 °C to 125°C SG2549Y -25 °C to 85°C SG3549Y 0 °C to 70°C CONNECTION DIAGRAMS & ORDERING INFORMATION (See Notes Below) 8-PIN PLASTIC DIP M - PACKAGE SG2549M -25 °C to 85°C M Package: RoHS / Pb-free 100% Matte Tin Lead Finish SG3549M 0 °C to 70°C M Package: RoHS Compliant / Pb-free Transition DC: 0503 Note 1. Contact factory for JAN and DESC product availability. 2. All parts are viewed from the top. D Package Pb-free transition DC:0440 100% Pb-free Matte Tin Lead Finish |
Similar Part No. - SG2549 |
|
Similar Description - SG2549 |
|
|
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 |