NG e14~1

TOM TAT NHLTNG

KET

QUA CHINH CUA

D £ TAI N C K H

Ten d§ tai: Nghien cuu thief k^ ch^ tao bo t6 hop t^n s6 dai tSn 902MHz-928MHz
voi CO' cau chuyen tan linh hoat va tu* dong dieu chinh tan so, sii dung trong cac
he thong tin v6 tuyen va mang khong day.
Mas6:QC.06.11
1. Chii tri de tai: TS. Bach Gia Duong
2. Nhung ket qua chinh:
a) Ket qua ve khoa hoc (nhung dong gop ciia de tai. cac cong trinh khoa hoc da cong
b6):
Trong qua trinh thuc hien de tai. chung loi da c6 mot bai bao dugc dang trong
tai lieu cua Hoi nghi V6 tu\en dien tu toan quoc (REV 10). Ha Ngi. thang I 1 nam
2006.
Bach Gia Du'O'ng. "Research, design and construction of PLL Frequenc)
Synthesizer operating in dm band with the mechanism of flexible frequcnc)' change
for Automatic Frequency Control System"

b) Ket qua phuc vu thuc te (cac san pham cong nghe. kha nang ap dung thuc te):
San pham da thani du TechMart Ha ngi 2006. c6 nhicu dia chi ap dung trong
thong tin v6 tuyen. trong cac ihict bi quan su. rada song dm.
c) Ket qua dao tao (so Jugng sinh \ien. hoc \'ien cao hgc. nghien ciru smh lam \ lec
trong de tai):
Trong khuon kho thuc hien de tai. da c6 2 luan \an cao hoc \a 4 khoa luan lot
nghiep dai hgc he chinh quy duo'c hoan thanh \di ket qua loai gioi:
•

Vu Quang Duy. "Nghien cuu cac giai phap ky ihuat \a cong nghe chc lao
nham nang cao do tin ca)' cua he thong thu phal \a xu Iv du lieu trone man"


khong day dai song 902-928MHz'\ Luan van tot nghiep cao hgc. Dai hgc Khoa
Hoc Tu Nhien, Dai hoc Qu6c Gia Ha Ngi, 2006.
•

Nguyin Ngoc Khai, "Nghien cuu cac giai phap ky Ihuat lam tang cu ly ket noi
thong tin trong mang khong day'", Luan van lot nghiep cao hgc. Dai hgc Khoa
Hoc Tu Nhien, Dai hgc Qu6c Gia Ha Ngi, 2006.

•

TrSn Hi^u Minh, "Nghien ciiu-Thiet ke-Che tao he thong chuyen tan linh hoat
su dung lam mach AFC nho to hgp tan so dung mach vong bam pha^\ Khoa
luan tot nghiep dai hgc he chinh quy, Dai hgc Cong Nghe. Dai hgc Quoc Gia
Ha Ngi, 2006.

•

Doan Le Hu'ng, "Nghien cuu, thiet ke, che lao bg to hgp tan so dai song met
(150-200MHz) dung mach vong bam pha'', Khoa luan tot nghiep dai hgc he
chinh quy, Dai hgc Cong Nghe, Dai hgc Quoc Gia Ha Ngi. 2006.

•

Trjuh Quang Thanh, "Nghien cuu thiet ke che tao he thong chuyen tan linh
hoat dai song dm bang phuong phap to hgp tan so". Khoa luan tot nghiep dai

hgc he chinh quy, Dai hgc Khoa Hgc Ty Nhien, Dai hgc Quoc Ciia Ha Ngi.
2007.

•

Vu Anh Tuan. "Xay dung he thong ty dong dieu chinh tan so song mang dai
song dm". Khoa luan tot nghiep dai hgc he chinh qu)'. Dai hgc Khoa Hgc Tu
Nhien. Dai hgc Qu6c Gia Ha Ngi. 2007.

d) Ket qua nang cao tiem lire khoa hgc (nang cao trinh do can bg \'a tang cuong Irang
thiet bi cho don vi):
Ngay nay voi toe do phal trien cao. nganh dien tu da khong ngung thav doi. cai
tien. cho ra doi nhirng he thong. nhCmg thiet bi linh vi \'a hien dai ho'n trong ca Ihih
vuc dan su va quan sy. Cac bg to hgp Ian so dung vong bam pha PLL duoc ung dung
rgng rai trong cac tram khong da\-. cac thiet bi di dong cani law trong thong tin lien lac
ha\ trong cac mang ngi bo... Nhu cau su dung cac he thong na\' dang gia tang khons
ngimg trong ky nguyen ky thuat so hien nay. Do \'a\' \-iec nghien cuii chc tao cac bg
tao dao dong tan so sieu cao chat hrgng lot dang la mot moi quan lam Ion cua cac nha
nghien cuu tren khap the gioi.


e) Tinh hinh su dung kinh phi: Da sii' dung het kinh phi, dung thoi han va mue dich chi
tieu, da hoan chinh cac thu tuc thanh toan tai Bg phan Tai vu ciia truong Dai hgc Cong
Nghe. CO ban ke khai chi tiet trong phan bao cao.
CHU NHIEM DE TAI
(Ky va ghi ro ho ten)

XAC NHAN CUA DON VI
(Ky va ghi ro ho ten)

TS. Hack &^ Ou^/h

7

XAC NHAN CI)A CO QUAN CHU QUAN


SUMMARY

Project Title:
Research, Design and Implementation of a Frequency Synthesizer
operating at 902MHz-928MHz with feature of flexibly and automatically
changing operating frequency, used in Wireless LAN and Wireless
Communication System
Code number: QC.06.11
Coordinator: Vietnam National University, Hanoi
144 Xuan Thuy Road, Hanoi, Vietnam
Implementing Institution:
Research
Center
for
Electronics
and
Telecommunication, College of Technology, Vietnam National University,
Hanoi
02 Building, 144 Xuan Thuy Road, Hanoi, Vietnam
Cooperating Institution(s):
Duration: from June 2006 to June 2007
1. Objectives:
Products:

- Implementation of 01 frequency synthesizers operating at various frequency
bands
Publications:
- 01 paper presented at REV'2006
Education and Training
- 01 Master's Thesis
- 01 Graduation's Thesis

2. Main contents:
In this project, we study theory and technique to implement a PLL circuit
and Frequency Synthesizer and the features of IC ADF41 Ix so as to desien


and implement frequency

synthesizers that meet the objectives and

requirements of the projects.
3. Results :
Products:
- Implementation of a linear, noise-proof, and stable VCO with
driver voltage from 0 to 15V,
- Implementation of 04 frequency synthesizers operating at various frequency
bands to be presented in Techmarch Hanoi 2006
Publications:
- 01 paper presented at REV'2006
Education and Training
- 02 Master's Thesis
- 04 Graduation's Thesis

MUG LUC
PHAN M O DAU
Bang cac chu cai viet tat
Danh sach nhung nguai tham gia thuc hien de tai
Danh muc cac hinh
Danh muc cac bang so lieu
BAO

CAO

TONG HOT

I. DAT VAN DE

1

XL NOI DUNG CHINH

2

1. Mach vong bam pha va bo to hgp tan so

2

1.1. Mach vong bam pha
1.1.1. Giai thieu chung
1.1.2. Tong quan ve vong bam pha (PLL)
1.2. Bo to hop tan so dung vong bam pha

2
2
7

1.2.1. Bg so pha
1.2.2. Cac bg chia tan
1.2.3. Bg Igc tan so thap

8
9
10

1.2.4. Bg dao dong dieu khien bang dien ap VCO

10

2. Gioi thieu ve ho IC ADF411x
2.1. Ho IC ADF411X
^ 2.2. Mo ta chuc nang cac chan
'

2

2.3. Mo ta chuc nang mach dien

11
H
]?>
15

2.3.1. Tang loi vao chuan

15

2.3.2. Tang loi vao RF

15

2.3.3. Bochiatru6c(P/P+])

16

2.3.4. Bgchia A vaB

16

2.3.5. BgchiaR

17

2.3.6. Bg tach song pha/tan so

17

2.3.7. Thanh ghi dich 24 bit

17

2.3.8. Bg ghep bgi loi ra va bg tach xung dong bg

18

3. Ket qua thuc nghiem

20

3.1. Chg tao VCO

20


3.2. Che tao bo to hop tan so
3.2.1. Che tao bo to hgp tan so dugc dieu bang vi dieu khien
3.2.2. Che tao bg to hgp tan so dieu khien ghep noi may tinh
III. K £ T LUAN
IV. DANH MUC CAC CONG TRINH DA CONG BO
V. DANH MUC CAC SAN PHAM DAO TAO
VI. TAI LIEU THAM KHAO

24
24
29
39
40
41
42


BANG CAC CHiT CAI VIET TAT
PLL

Phase Locked Loop

DDS

Direct Digital Synthesis

DA

Digital to Analog

VCO

Voltage Controlled Ossillator

LPF

Low Pass Filter

PFD

Phase Frequency Detector

CMOS
AFC

Complementary Metal-Oxide Semiconductor
Automatic Frequency Control

DANH SACH N H U X G N G U O I THAM GIA THI/C H I E N D £ TAI
Ho va ten
1. Bach Gia Duong

Hoc ham, hoc vi

Co* quan cong tac

Tien sy

Trung tarn nghien cuu DT-VT, Truang

(chu nhiem de tai)

DH Cong Nghe, DHQGHN

2. VQ Tuan Anh

Cu nhan

Trung tarn nghien cuu DT-VT, Truang
DH Cong Nghe, DHQGHN

3. Nguyen Anh Tuan

Cu nhan

Trung tarn nghien cuu DT-VT, Truang
DH Cong Nghe, DHQGHN

4. Tran Anh Tuan

Thac sy

Trung tarn nghien cuu DT-VT, Truang
DH Cong Nghe, DHQGHN


DANH MUC CAC HINH
Hinh 1. Sado chuc nang cua mach vong bam pha (PLL)

3

Hinh 2. Dae trung chuyen tan so - dien ap cua PLL
Hinh 3. Su phu thugc cua tan so VCO vao dien ap

6
6

Hinh 4. Sa do chuc nang bg to hgp tan so dung mach vong bam pha

7

Hinh 5. Cau true cua 1 bg so pha so
Hinh 6. Gian do xung loi vao/ra (IN/OUT) khi chua bat chap
Hinh 7. Gian do xung loi vao/ra (IN/OUT) khi tan so 2 loi vao bang nhau

8
9
9

Hinh8. IC ADF411X
Hinh 9. So d6 chuc nang cua hg IC ADF 41 Ix
Hinh 10. Cac thong so ve khoang each cua 2 loai IC 20 chan gam
va 16 chan ret
Hinh 11. Tang loi vao chuan

11
12
13
15

Hinh 12. Tang loi vao RF

16

Hinh 13. Bgchia A vaB

16

Hinh 14. So do nguyen ly da dugc dan gian hoa va gian do xung cua
bg tach song pha/tan so

17

Hinh 15. Luge do dinh thai

18

Hinh 16. MachMUXOUT

18

Hinh 17. So do nguyen ly hoat dong ciia VCO

20

Hinh 18. VCO ban din dai ikn s6 600-700MHz

21

Hinh 19. Bieu do phu thugc tan so vao dien ap cua VCO

22

Hinh 20. Su phu thugc cua VCO 500-1000 MHz vao dien ap

24

Hinh 21. Bg dao dong dugc dieu khien bang dien ap. dai tan 500MHz-lGHz

24

Hinh 22. So' 66 khoi bg to hgp tan so dugc dieu khien bang \'i dieu khien

26

Hinh 23. So' do nguyen ly bg to hgp tan so dugc dieu khien bang vi dieu kJTien

26

Hinh 24. So do chuc nang he thong AFC

27

Hinh 25. Bg t6 hgp Van s6 dai t§n 800MHz-lGHz

28

Hinh 26. Bg t6 hgp t§n s6 voi cac tin s6 phat 820MHz. 840MHz.
860MHz. 880MHz

28

Hinh 27. Bg id hgp tan so voi cac tan so phat 902MHz- 91 IMHz.
920MHz, 928MHz

29

Hinh 28. So' do khoi bg to hgp tan so dieu khien ghep noi ma)' tinh

30


Hinh 29. Sado nguyen ly bo to hgp tan so dieu khien ghep noi may tinh

30

Hinh 30. Sado cap noi bo to hgp tan so vai may tinh

31

Hinh 31. Bg to hgp tan so dieu khien ghep noi may tinh

32

Hinh 32. Giao dien chucmg trinh phan mem tien ich ADF_Rev3.I
Hinh 33. Ket qua tren may phan tich ph6 -tin s6 820MHz

32
33

Hinh
Hinh
Hinh
Hinh

s6 840MHz
s6 860MHz
s6 880MHz
s6 902MHz

34
34
35
35

Hinh 38. Ket qua tren may phan tich pho - tan s6 908MHz
Hinh 39. Ket qua tren may phan tich pho - tan so 913MHz

36
36

Hinh 40. Ket qua tren may phan tich pho - tan so 920MHz
Hinh 41. Ket qua tren may phan tich pho - tan s6 928MHz
Hinh 42. Ket qua tren may phan tich pho - tan so 930MHz

37
37
38

34. Ket
35. Ket
36. Ket
37. Ket

qua tren
qua tren
qua tren
qua tren

may
may
may
may

phan
phan
phan
phan

tich
tich
tich
tich

ph6 - tin
ph6 - tin
ph6 - tin
ph6 - tin


DANH MUC CAC BANG SO LIEU
Bang 1. Bit dieu khien lira chgn chgt dir lieu
Bang 2. Sir phu thugc tan so vao dien ap cua VCO ban dan

18
21

Bang 3. Sir phu thugc tan so vao dien ap cua VCO su dung IC

23


QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

BAO CAO T 6 N G H O P
I. DAT VAN DE

Ngay nay, Cong nghe thong tin va Dien tu - Vien thong la mot trong cac ITnh
vuc phat trien hang dau, chiem uu the va giu vai tro tat yeu trong hau het mgi ITnh
vuc. La phuong tien thuc day nen kinh te phat trien hem, van hoa xa hoi dugc nang
cao han, khoa hgc ki thuat ngay cang phat trien hem, giup cho cugc song con nguai
tra nen hien dai va tien nghi han. Vai toe do phat trien cao, nganh dien tu da khong
ngung thay doi, cai tien, cho ra dai nhung he thong, nhung thiet bi tinh vi va hien
dai hem trong ca ITnh vuc dan su va quan su. Cac bg to hgp tan so dung vong bam
pha PLL dugc ung dung rgng rai trong cac tram khong day, cac thiet bi di dong
cam tay, trong thong tin lien lac hay trong cac mang ngi bg...D6 la mot thiet bi
dien tir dung de phat ra cac tan so kliac nhau c6 lien quan chat che voi tan so chuan.
Cac bg to hgp tan so loai nay dugc cau tao nen tu cac khoi nhu: bg tach song
pha/tan so, bg Igc thong thap, bg dao dong dugc dieu khien bang dien ap. Bg to hgp
tan so la mot phan tu rat ca ban va quan trong trong cac thiet bi. cac he thong thong
tin vo tuyen su dung tan so sieu cao. Nhu cau su dung cac he thong nay dang gia
tang khong ngung trong ky nguyen ky thuat so hien nay. Do vay viec nghien cuu
che tao cac bg tao dao dong tan so sieu cao chat iugng tot dang la mot moi quan
tarn Ion cua cac nha nghien ciru tren khap the giai.
Trong de tai nay chung toi da che tao dugc 4 bg to hgp tan so c6 cac tinh
nang voi chat Iugng cao nhu tan so phat ra chuan, it nhieu. su dung it nang Iugng,
kich thuoc nho ggn, c6 the thay doi dugc tan so de dang nha ket noi voi vi dieu
khien hoac ghep noi may tinh.


QC.06.11

£)ai hoc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

11. NOl DUNG CHINH
1. MACH VONG BAM PHA VA BO TO HOP TAN S 6
1.1. Mach vong bam pha

1.1.1. Gi6*i thieu chung
Bg tao dao dong sieu cao tan chiem mot vai tro rat can ban trong cac he
thong thong tin vi no tao ra cac song tham chi^u su dung trong viec dilu chi va giai
dieu che...Trong cac he thong nhu vay, tinh chinh xac va 6n dinh cua cac bg tao
dao dong iuon phai dugc quan tam nhim dam bao chit Iugng cua he thdng.
Cho den nay da c6 iihieu phuong phap dl tang tinh 6n dinh cua bg tao dao
dong, trong do dang chu y la ky thuat vong bam pha PLL (phase locked loop) va ky
thuat tong hgp so true tiep DDS (direct digital synthesis). M6i ky thuat diu c6
ahung dilm manh va yeu rieng. Ky thuat DDS la mot he th6ng ha. su dung may
tinh so va cac bp bien doi DA (digital to analog) d^ tao ra cac tin hieu mong mu6n.
Day la ky thuat tong hgp tan so true tiep. Ky thuat nay c6 uu dilm n6i bat la thai
gian thiet lap tan so rat nhanh, do phan giai tan s6 rit nho. Tuy nhien nhugc dilm
cua no la tieu thu nhieu nang Iugng va chi thich hgp voi dai tan co vai tram MHz.
Trong khi do, ky thuat PLL lai su dung he thong hoi tilp kin, trong do do 6n dinh
cua hoi tiep la quan trgng nhat. Day la ky thuat tong hgp tan so gian tiep. Ky thuat
nay yeu han DDS a thai gian thiet lap tan so. tuy nhien. no lai c6 uu diem la tieu
thu rat it nang Iugng. va rat thich hgp vai dai tan sieu cao, la dai tan so tu 300MHz
den 3 GHz.
1.1.2. Tong quan ve \6ng bam pha (PLL)
He thong tu dong dieu chinh tan so theo pha ha\- con ggi la vong bam pha
PLL dugc su dung rgng rai trong viec su ly tin hieu tuang tu \'a cac he thong so.
Mot so ung dung quan trgng cua vong bam pha la dieu che va giai dieu che FM.
giai dieu che FSK (FSK demodulation), giai ma am thanh. nhan tan. dong bg hoa
xung dong bg, to hgp tan so, ma}' phat dieu tan...
Vong bam pha dugc mo ta Ian dau tien vao nhung nam 1930. khi do no dugc
ung dung trong viec dong bg quet doc va quet ngang trong v6 tu}"cn truycn hinh.

2-

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

QC.06.11

Cling vai su phat triln cua cac vi mach tich hgp. no dugc tim thay trong rat nhieu
ung dung khac. Vao khoang nam 1965, nguai ta da tao ra nhung IC PLL dau tien.
chi su dung cac thiet bi tuong tu. Nhung tien bg ngay nay trong san xuat \'i mach
tich hgp da gia tang viec su dung cac thiet bi PLL vi no ngay cang re va c6 do tin
cay cao. Hien nay PLL da c6 the dugc tich hgp toan bg tren mot don chip.
Mach vong bam pha PLL ca ban dugc trinh bay trong so do chuc nang hinh
1, bao gom nhimg phan chinh la bg so sanh pha. bg Igc thong thap. may phat tan
s6 dugc dieu khien bang dien ap VCO (voltage controlled ossihator). Ba khoi na}hgp thanh mot he thong phan hoi ve tan so khep kin.

Loi vao tin hieu

v.(t)
fs

Loi vao so sanh

v,(i)

So sanh pha

Lgc tan so thap

Vo(l)

f()

Vd(t)

VCO

Dien ap dieu khien VCO

Hinh 1. So do chuc nang cua mach \ong bam pha(PLL).

Khi khong c6 tin hieu \ a o PLL. sir chenh lech dien ap \',(t) o loi ra cua bg
so sanh pha (phase comparator) bang khong. Dien ap \'^{{] o loi ra cua bo loc tan
thip cunu b.'ing khong. Ma\- phat tan so dieu khien bang dien ap \'C(.) hoai donii o
tin so dmh fo ggi la tan so dao dong trung tam. Khi co tin hieu dua \ao lie thong
PLL. bo so pha se so pha \'a tan so cua tin hieu loi \ a o \a\ pha \a tan so cua \ ' C 0
\'a tao ra mot dien ap sai so V,(t) ti le \'(n su lech pha \a chcnh icch tan so cua tin
hieu loi vao va VCO. tuc la phan anh su khac nhau ve pha \a tan so cua 2 un hieu.
Dien ap sai so na^• dugc loc roi dua vao loi vao dicu khien cua \'CO. Dicn the dieu


QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

khien V(|(t) thuc day tan so cua VCO thay doi theo huong giam hot su khac nhau ve
tan so giua tin hieu fo va tin hieu loi vao. Khi tan s5 ]6i vao I^ ti6n din din tan so todo tinh chat hoi tiep cua PLL se thuc dly VCO d6ng bg hoac bit chap voi tin hieu
loi vao. Sau khi chap, tan so VCO se bang tan so cua tin hieu 16i vao. tuy nhien van
CO do chenh lech ve pha nao do. Su chenh lech ve pha nay la cin thilt vi no tao ra
dien ap sai Ve(t) de chuyen tan so dao dong tu do cua VCO thanh tin s6 ciia tin
hieu vao f^, nhu vay se giu' cho PLL 6 trang thai giu chap tin s6. Kit qua la tin s6
cua dao dong VCO c6 do on dinh tan so ngang cap voi do on dinh tan so cua tin
hieu so sanh pha voi tan so VCO. Nhu vay neu su dung fc, la dao dong chuan thach

anh CO do on dinh tan so cao thi ket qua mach vong bam pha se cho do on dinh tan
so cua VCO ngang cap thach anh. Khong phai tin hieu nao VCO cung bat chap
dugc. Dai tan so tren do he duy tri tinh trang chap voi tin hieu loi vao dugc ggi la
dai giu' chap hay giai bam (lock range) cua he thong PLL. Dai tan so tren do he
thong PLL CO the bat chap mot tin hieu vao ggi la dai bat chap (capture range). Dai
bat chap bao gia cung nho hon giai giu' chap.
Cliung ta CO the dung mot each khac de mieu ta hoat dong cua PLL la bg so
sanh pha thuc chat la mach nhan. no trgn tin hieu \'ao \'6i tin hieu VCO. Sir trgn
nay tao tan so tong va tan so hieu f^ ± TQ. Khi mach a trang thai chap thi hieu tan so
f^ - f(i = 0. do do no tao ra thanh phan mot chieu. Bg loc tan so thap loai bo thanh
phan tan so tong f^ + IQ. nhung tiep nhan thanh phan dien ap mot chieu. tire la chi
cho thanh phan mot chieu di qua. Thanh phan mot chieu na\" dieu khien \ ' C 0 hoat
dong 0' trang thai giir chap voi tin hieu vao. Can chii y rang giai chap doc lap \6i
dai tan so cua bg lgc tan so thap vi rang khi mach o' trang thai giir chap thanh phan
hieu tan so bao gio cung la dong mot chieu.
1.1.2.1. Bat chap va giu chap
Khi mach chua o' trang thai bat chap, bg so pha trgn tin hieu \'ao \oi tin hieu
VCO de tao ra thanh phan tong \'a hieu hai tan so. Ncu thanh phan hieu nam ben
ngoai bicn dai tan so cua bg lgc tan tlia]) thi no se hi loai bo cung thanh plian tong
tan so. do do trong mach sc khong co thong Im nao dirge truycn qua mach loc va
\''C0 tiep tuc hoat dong o" tan so trung tam ban dau. Khi tan so tin hieu vao tien dan
den tan so phat cua VCO thi thanh phan hieu giam xuong \a tien dan diMi bicn dai


QC.06.11

Dai hgc Cong Nghe-Dai hgc Qu6c Gia Ha Noi

tan so ciia bg lgc tan thap. Liic do, mot phan ciia thanh phan tin hieu di qua dugc bg
lgc tan thap va thiic day VCO chuyen den tan so ciia tinh hieu vao theo huong sao

cho thanh phan hieu tan so giam va cho phep nhieu thong tin nua di qua bg lgc tan
thap den VCO. Day la co che hoi tiep duong thiic day VCO chap voi tin hieu \ao.
1.1.2.2. Dae trung chuyen tan so sang dien ap.
Hinh 2 cho chiing ta thay dac trung chuyen tan so sang dien ap dien hinh ciia
PLL. Cho tin hieu vao PLL, tan so cua no dugc quet tii' tii' tren mot dai rgng. True
thang dimg la dien the tuong iing V^ ciia mach. Tren hinh 2a la truong hgp tan so
tin hieu tang dan, mach khong phan img gi voi tin hieu cho den khi tan so tin hieu
dat teVi tan so o^i tuong img voi bien duai ciia viing bat chap. Liic do he bat chap voi
tin hieu vao va tao ra buac nhay ciia dien the V^ voi dau am. Sau do, VCO tha)- doi
tan so vai he so goc bang nghich dao ciia he so khuech dai loi vao VCO (1/Ko) va
di qua gia tri VQ Idii O^I^COQ mach bam sat tin hieu vao cho den khi tan so tin hieu
vao dat den CO2 tuong ung voi bien tren ciia khoang giu" chap. Khi do he niat bam.
dien the V^^ tut xuong VQ va tao ra tan so dao dong tu do ciia VCO (hinh 2a).
Neu ta lai cho tan so tin hieu vao quet theo chieu huong giam dan thi qua
trinh lap lai nhung dao ngugc so vd\ truac (hinh 2b) mach bat chap lai vai tin hieu
a CO-, tuong img voi bien tren ciia dai bat chap va bam sat theo tin hieu vao cho 6Qn
khi tan so cua tin hieu vao bang 0)4 tuong img voi bien do cua dai giir chap.
Nhu vay la dai bat chap cua he la (031.(03) va dai giu chap la cua he (oh-oij).
Do dac trung ciun'en tan se") - dien ap nhu tren nen PLL co tinh chgn Igc voi
tan so trung tam VCO. no chi co phan img doi voi nhung tan so tin lueu \ a o sai
lech so \oi (.0,1 la (o^ hoac (Oi_ {iOc^{(0yO)i)/2 \a 03| =(o):-eo4)/2). tuy theo mach bal
dau CO hay khong co dieu kicn giir pha ban dau.
Su tuyen tinh cua dac trung chu>'en doi tan so sang dien ap cua PLL chi do
he s6 chu\en doi cua VCO qu\et dinh. do do ta thirong doi hoi \ ' C 0 co dac tinh
chu\"en dien ap sang tan se"* o mire do tuyen tinh cao.


Dai hgc Cono Nehe-Dai hgc Quoc Gia Ha Ngi

QC.06.1

V.

+

V,
Huong quet tan so
a/

Vd

+

V,
Hue^ng quet tan so

b/
Dai bat chap
Hinh 2. Dac trung chu)'en tan so - dien ap ciia PLL

Hinh 3 trinh bay duong dac trung cua su phu thugc tan so phat ciia VCO vao
dien ap dieu khien V^i o' da\- f^^^ va fm,,! la tan so cua may phat VCO tuong img voi
tan so goc CO2 va e04. Khi do dai giu' chap ciia he la: Afi^ ^ imax - Imm
Neu ggi is la tan so ciia tin hieu loi vao thi dai bat chap cua he PLL la:
A f C = fsm;,x - Isinin

ivonn do fsmax ^•a fsmm la ^an so ciia tin hieu tuong img vai tan so goc 0)3 \'a cO].

\'C'() (kl-lz)

V,

* max

Hinh ?. Sir phu thuoc cua tan so VCO \ao dien ap


Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

QC.06.11

1.2. Bo to hop tan so diing vong bam pha
Bg to hgp tan so dimg mach vong bam pha dugc su dung dua tren ngu)'en
tac tren da dugc su' dung rat rgng rai bai vi no co the tao ra tan so bat ky c6 do on
dinh cao ngang vdi thach anh va co the thay doi tan so rat mem deo dugc dieu
kliien mot each de dang bang cac bg vi xu ly.
So do chiic nang bg to hgp tan so dugc trinh bay tren hinh 4.

''

Bg dao
dong VCO

fvco

''

Bo chia N

Bo so sanh

pha

Bo loc
thong thap

Bo chia R

Bg dao
done chuan

f,el

Khuech dai
mot chieu

Hinh 4. So" do chii'c nang bg to hgp tan so diing mach vong bam pha.

Tan so loi ra ciia bg chia N - dem/dinh thai gian lap trinh hoa - bam pha voi
tan so chuan dugc lay tir loi ra ciia mot dao dong thach anh. He so chia N co the
thay doi dugc nho ma dieu khien tan so (leqiiency control code). Bo so sanh pha se
so sanh pha giira tan so loi ra cua VCO qua bg chia N \'6i tan so chuan tao ra tu dao
dong thanh anh i]^i qua bo chia R. dien ap sai so o- loi ra tach song pha. qua bo lgc
tan thap (LPF - low pass lllter) chu>en thanh dien ap mot chicu bien doi cham \\^
dirge du"a \ao dicu khien VCO lam cho tan so loi ra cua bg chia N bam pha \oi tan
so chuan. Nhu va)' ta se co tan so loi ra cua \''C0 la: fvco=N/R.r,-ef.
Do do chi can tha\' de^i he so chia N, R thi ta se tao dirge cac tan so khac nliau e> loi
ra cua VCO.
Sau da)' la nhung thanh phan co ban ciia mot bg to hgp tan so kieu PLL. Do

QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Noi

bg to hgp tan so kieu PLL dua tren nguyen ly PLL la co' ban, nen nhung thanh phan
vong bam pha PLL ciing dugc giai thieu.
1.2.1. Bo so pha
Co the noi, trai tim ciia mot he thong PLL chinh la bg so pha. Day la noi tin
hieu mang tan so tham chieu dugc so sanh voi tin hieu phan hoi tii- loi ra ciia VCO.
va tin hieu sai kliac tim dugc se dugc sii' dung de dua vao bg Igc thong thap va
VCO. Trong cac he thong PLL so (DPLL - Digital PLL). bg so pha la mot phan tir
logic. Co the phan loai bg so pha theo thanh phan cau tao ciia no:
•

Mach XOR

•

Trigo .I-K

•

Bg so pha so
Voi bg so pha so. loi ra ciia no khong nhung the hien sai kJiac ve pha ma con

the hien ca sai kliac ve tan so giia'a 2 tin hieu loi vao. Ngu)'en ly hoat dong cua bg
so pha so dugc minh h.oa trong hinJi 5. Thanh phan co' ban ciia no la 2 Trigo' D. Gia
sii' loi vao +1N la loi vao tan so chuan. va -IN la loi vao phan hoi tii' VCO. Ta co
gian do xung loi vao. loi ra nhu hinh 6. Can cir vao gian do xung ta thay:
- Neu tan so loi vao +IN cao han nhieu so voi tan so loi \'ao -IN thi tin hieu loi ra

hau nhu Iuon o mii'c cao. Suon xung len dau tien o +1N lam loi ra chuyen Icn mire
cao va dugc giu' o miic nay cho toi khi co suan xung len dau tien o -IN.
- Neu tan so loi \'ao +iN thap hon nhieu so voi tan so loi vao -IN thi ta se co dieu
nauo'c lai.

-D>H

Hinh 5. Cau triic cua 1 bo so pha so


QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia l^a Ngi

Trong do:
Delay: bg tre
U L U 2 : Cac trigo D
U3:bgAND
U4: bg dao

-' JuuuTrLruLruuui^.

Hinh 6. Gian do xung loi \ao/va (IN/OUT) khi chua bat chap.

Khi he thong PLL dang a trang thai giu chap ve tan so. tuy nhien van co mot chiit
sai khac ve pha thi ta co gian do xung nhu hinh 7.

•"^ .^.fLPJlJLmTrJlJlJITL
- jTaiijiruirirLrLRn.,
- _i_LJL_lLJLX J...__1L1J_J_..

Hinh 7. Gian do xung loi vao/ra (IN/OUT) khi tan so 2 loi vao bang nhau

Khi 2 loi \'ao +1N va -IN co pha gan nhu nhau thi tan so loi ra \'i\ ^IN som
pha hon -IN thi o' loi ra ta se nhan dugc mot chuoi cac xung duo'ng. Cac xung na)
se dieu khien VCO khien cho 2 tin hieu +1N va -IN dat den trang thai dop.g pha \6i
nhau.
L2.2. Cac bo chia tan
Trong mot bo long hgp tan so hgp tan so kieu so nguxcn (Integer N). do
phan giai tan so cua loi ra ducTc xac dinh bang Ian so tham chieu dua \ao bg so pha.
Chang han. neu ta can do rgng giai la 200KHz (nhu trong he thong GSM) thi khi do
tan so iham chieu dua \ a o bg so pha phai la 200KHz- 1 u\ nhien. de co dugc m(M


QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

nguon phat tan so chuan 200 KHz la khong he don gian. Ta co the khac phuc dieu
nay bang mot phuong phap don gian la sii- dung mot bg tao dao dong chat Iugng tot
(thuang la kieu tinh the) boat dong vai tan so cao roi chia nho tan so ciia bg tao dao
dong do. Trong vi du nliu vira neu o tren, ta co the co dugc tin s6 chuin 200KHz
bang each chia tan so lOMHz (ciia bg tao dao dong thach anh) cho 50. Trong so d6
khoi cua bg to hgp tan so (hinh 4). day la bg chia N. Trong so d6 hinh 4 cung cho ta
thay trong he thong khong chi co bg chia N ma con co bg chia M. Bg chia M la mot
phan til' co the lap trinh dugc de thiet lap m6i quan he giua tin s6 16i vao va tin s6
loi ra trong he thong PLL. Bg chia N co cau triic ngay cang phii'c tap la do xult phat
til' nhu cau phai chia cac tan so rat cao phan hoi tu cac VCO.
L2.3. Bo loc tan so thap
Su khac nhau ve tan so giua VCO va tin hieu loi \-ao qua bg tach song pha
va bg lgc tan so thap tao thanh dien ap sai Ve(t). Dien ap nay dong vai tro dien ap

dieu khien Vfi(t) cho tan so phat VCO.
Neu tan so tin hieu loi vao fs va tan so phat cua VCO In bang nhau mot each
chinh xac thi tin hieu loi ra ciia bg lgc tan so thap se la mot dong khong doi (mot
chieu) ma bien do cua no phu thugc vao hieu pha ciia hai tin hieu fs \'a f„.
1.2.4. Bo dao dong dieu Idiien bang dien ap VCO (Voltage Controlled
Ossillator)
Til' nguyen ly cua \'-6ng bam pha. chiing ta thay rang su khac nhau \-e tan s6
giu'a ma)' phat VCO va tin hieu loi \'ao ciia mach tach song pha tao thanh dien ap
sai. qua mach Ige tan so thap tao thanh dien ap dieu khien lac dong \ao max phat
\ ' C 0 . dieu chmh dich tan so cua ma)' phat cho Irimg khop \a\ tan so cua tin hieu
\'ao. \'6'i lap luan tren thi mot dien ap sai. dien ap na) dong \ai tro dien a]? dieu
khien tac dong vao ma)' phat VCO lam tha)' doi tan so phat fo. Vlgt \eu cau r^t
quan trgng dat ra doi \'e7i VCO la su phu thugc eua tan so \ a o dien ap dieu khien
phai iu)'cn tinh ti'cn khoang tu)'en tinh VCO.


QC06.il

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

2, GIOI THIEU V £ HO IC ADF411x
De to hgp tan so a dai song dm va cm chiing toi sir dung bg to hgp tan so
diing mach vong bam pha PLL dua tren vi mach ADF411x ciia hang Analog
Devices.
2.1. HoICADF411x
Trung tam ciia bg to hgp tan so ma to de tai nghien cim la mot IC ADF4113
thugc hg ADF41 Ix. Loai IC nay co chirc nang tao ra dao dong song mang ciia cac
thiet bi thu va phat v6 tuyen. No gom mot bg tach pha/tan so PFD (phase frequency
detector) dugc so hoa vai do on thap, mot bg tao dong chinh xac, mot bg chia
chuan kha trinh R(14 bit), hai bg chia kha trinh A(6 bit) va B(13 bit), mot bg chia

truac mo-dun kep (P/P+l). Cac thiet bi boat dong vai nguon cung cap 2.7V-5.5V
va CO the a trang thai tieu ton it nang Iugng khi khong sir dung. De tao thanh mot
vong bam pha PLL hoan chinli chi can thiet ke them VCO ben ngoai. Dieu khien
tat ca cac thanh ghi la mot giao dien ba duong dem gian. So do chu'c nang ciia hg IC
ADF 41 Ix dugc mo ta trong so do hinh 9.
TSSOP

RSETH

LFCSP

O- J« Q. >
o a > D

•

C P [ I ADF-inO
C P G N D I T A D F i l l l T4] MUKOUT
'—' ADF4112
A G N D [ T ADPai 13
nF|,,B[T TOP VIEW fr^DATA
'—(Noiio Scale) ^—'
RF|„A|T
^CLK

>
D

CPGNDJJJ

ADF4110

C!]"UXOi

AGNDm
__^
AGND[T]

ADFJin
ADFdn2
ADFJ113

RIILE
.
[lIJDATA

ni^iriAil]

AVDDE

10] CE

REF|,j [ 7

7 ] DGMD

[IIJCE

., R R R R J g l J
O

i

Hinh 8. IC ADF411x.

Ci

t

^

^

O

D

f^' 0


QC.06.11

Dai hgc Cong Nghe-Dai" hgc Quoc Gia Ha Ngi
*Vic.

DVc«

BEFEBEUTE

M F,„ r '

R COyMIER

FWASE
FFCOUEttCT
[>ETECTOF

Jti
fl < OiJMTEB
LA.TCH

! H f U I BECi'STEfi

UATC«

cufftEin

t 1 t 1 1t
cpi-i CFL- - t n i CF>= • : n - CFI.:

fB&M
PJNCTlOn
L*TCH

ECCJUTER
LO*D'

I

4 -JCUIMER

n

Kx-^.-T •

n

r.ti

11

(.c

m

ADF4110.'ADF411
ADF4112.'ADF411

*(jlJC'

C'GNr

HinJi 9. So do chiic nang ciia hg IC ADF 41 Ix.
Hg IC ADF. 4] Ix co nhieu kieu dang va hinh dang Idiac nhau. Co the la loai
2 hang chan. hoac cung co the la loai 4 hang chan. Cung co the la loai chan ret (ha)con ggi la chan chia). hoac cung co the la chan gam. Hinh 8 cho ta thay 2 loai co
ban va su phan bo chii'c nang cac chan tren IC. Cac thong so k! thuat ve cu ly eua 2
loai IC tren duo'c chi ro trong so do hinh 10. Trong do, hinh 10a la IC 20 chan ehia
thanh 4 bans chan ^am. hinh 10b la IC 16 chan ehia lam 2 hane chan ret.

- 12

QC.06.11

Dai hgc Cong Nghe-Dai hgc Quoc Gia Ha Ngi

0.60
MAX

4.0
BSC s o "

MAXIRUUUUU
prN ,
INDICATOR

-1^

^
TOP
VIEW

3,75
BSC SQ

BOTTOM
VIEW

210
1.9:.

^Jfc

L^"SrhnnnhOoO MAX
0,^5 T Y P '

12'^ MAX

M^f

t==lUi4J-lJ-LF;

T^H K
0,50
ESC

^— o.2ri Iv

^ ^
0,,Ki

0.2?.
0.18

0, or. MAX
O.Uz^ NOM

0.S& T J
SEATING
PLANE

O.of. t

o"2o3

COPLANARITY
COS

REF

(a)

5.10
^

f

^

_5A10

uuhu

•It

1

.;

4. so

40
B;

4.40
4.30

J

PIN 1 ^

mum.
• 1

•^.

•

'

x4-

0.20

gl

MT^
^
COPLANARITY
0.10

I

o^^i/(

SEATl.-.
PLAfJE

TT_i:

^

^V
-Hk-OoO
-Hf
0 4^

(b)
Hinh 10. Cac th6n2 so ve khoane each cua 2 loai IC 20 chan ^am \'a 16 chan ret
2.2. IVI6 ta chirc nang cac chan

13