1. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)1 Chapter. 14 Chapter. 14 MOSFETs

2. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)2 V DD Substrate Source Drain SiO 2 V GG P Or V GG D S G  14-1. The Depletion-Mode MOSFET n

3. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)3 V GS IDID I DSS V GS(off) Deplition Mode Enhancement Mode V DS IDID V GS(off) -3 -2 V GS =0 +1 +2 여기서 V GS = +, - ☆ Normally on MOSFET (V GS =0 일 때는 정상적으로 동작 )

4. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)4 P n n n-type Inversion Layer V GG V DD D S G n-channel  14-2. Enhancement-Mode MOSFET

5. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)5 IDID I D(on) V GS(th) V GS V GS(on) ☆ Normally off MOSFET

6. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)6 실제로는 transconductance curve

7. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)7 100 ㎃  14-3. The Ohmic Region

8. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)8  Biasing in ohmic region

9. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)9 ※ ohmic region when

10. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)10 Ex) 14-1 Table 14-1 2N7000 이므로 ohmic region V G  4.5V “H”“L” V G  0V

11. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)11 ① Passive load switching  14-4. Digital Switching

12. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)12 ② Active-load switching two terminal device acts like a switch (ohmic region) Produces a two- terminal curve

13. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)13 * (i) (ii) (iii) * (iV)    의 >> 의 (10 배 정도 )

14. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)14  Complementary MOS - low power concumption - Invertor ① V in =+V DD  ② V in = 0V  Q1 off, Q2 on Q1 on, Q2 off ∴ V out  Ground ∴ V out  V DD P N ohmic region (acts like a switch) 0 +V DD 0  14-5. CMOS

15. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)15  High-power EMOS : motors, lamps, disk drive, primters, power supplies etc.  Discrete devices ( current 1A~200A, power 1W~500W)  Lack of thermal runaway ( positive temperature coefficient ) ; 내부온도 상승  R DS(on) 大  I D 小  온도 하강 (↔ Tr 은 negative temperature coefficient) 온도상승  V BE 감소  Ic 증가  온도 상승 V BE =-2mV / ℃  14-6. Power FETs

16. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)16  Power FETs in parallel  do not occur current hogging  lower V BE  more collector current Tr 의 경우 : FET 는 온도상승  R DS(on) 大  I D 감소  온도하강  Faster Turnoff ( Tr 은 minority carrier 가 축적되어 turn off 가 느림 )  Power FET 는 minority carrier 가 없어 Tr 보다 10~100 배 배 빨리 switch off 된다.

17. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)17  Power FET as an Interface  interface

18. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)18 Ex) ① 小① 小 ①大①大 ① on ① off n-channel p-channel 전류 ① on ② 大② 大 ② off ②小②小 ② on ② off no current ② Motor stop ① Motor turn

19. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)19  DC – to – AC Convertors -ups (uninterruptable power supply) op Amp. power off Generate on/off

20. 2016-07-06Mobile Communication Lab. (http://mobile pknu.ac.kr)20  DC – to – DC Convertors 0 +V GS(on)  - Full wave rectifier - Bridge rectifier ( for lower ripple )