Keywords: rf, rfdesign, rfic, vco, rfics, rf design, rf ics
Related Parts 


VCO Tank Design for the MAX2310

EQN1


EQN2

EQN3

EQN4

EQN5

EQN6

EQN6.1

Light grey indicates calculated values. 
Darker grey indicates user input. 
MAX2310 LowBand Tank Design and Tuning Range  
Total Tank Capacitance vs. V tune  
V tune  Total C  Ct
(Nominal) 
Ct (Low) 
Ct (High) 

0.5V  Ct high  14.1766pF  13.3590pF  14.9459pF  
1.375V  Ct mid  12.8267pF  11.7445pF  13.7620pF  
2.2V  Ct low  11.4646pF  10.3049pF  12.4534pF  
Tank Components 


C coup

18pF

0.9pF

5%


C cent

5.6pF

0.1pF

2%


C stray

0.70pF


L

68nH

2.00%


C int

0.902pF

10.00%


Parasitics and Pads (C stray)  
Due to Q 
C L

0.1pF


Ind. pad 
C Lp

1.13pF


Due to  
C diff

0.036pF


Var. pad 
C vp

0.82pF


Varactor Specs  
Alpha SMV1255003  
Cjo 
82pF

Varactor Tolerance


Vj 
17V

0.5V

19.00%


M 
14

1.5V

29.00%


Cp 
0pF

2.5V

35.00%


Rs 
1Ω

Reactance


Ls 
1.7nH

X Ls

1.82  
Freq 
170.00MHz


Nominal Varactor 
X c

Net Cap


Cv high

54.64697pF

17.1319

61.12581pF


Cv mid

27.60043pF

33.92

29.16154pF


Cv low

14.92387pF

62.7321

15.36874pF


Negative Tol Varactor (Low Capacitance)  
Cv high

44.26404pF

21.1505

48.42117pF


Cv mid

19.59631pF

47.7746

20.37056pF


Cv low

9.700518pF

96.5109

9.886531pF


Positive Tol Varactor (High Capacitance)  
Cv high

65.02989pF

14.3965

74.41601pF


Cv mid

35.60456pF

26.2945

38.24572pF


Cv low

20.14723pF

46.4682

20.96654pF


Nominal
LO (Nom) Range 
Low
Tol IF (High) Range 
Nominal
IF (Nom) Range 
High
Tol IF (Low) Range 

F low

162.10MHz

84.34MHz

81.05MHz

78.16MHz


F mid

170.42MHz

89.95MHz

85.21MHz

81.45MHz


F high

180.25MHz

96.03MHz

90.13MHz

85.62MHz


BW

18.16MHz

11.69MHz

9.08MHz

7.46MHz


% BW

10.65%

12.99%

10.65%

9.16%


Nominal IF Frequency 


Design
Constraints


Condition for bold number 
<IF

=IF

> IF


Delta 
0.66

0.21

0.62


Test 
pass

pass

pass


Raise or lower cent freq by 
0.21

MHz


Inc or dec BW 
1.28

MHz


Cent adj for min BW 
84.98

MHz


K vco 
10.68MHz/V

Light grey indicates calculated values. 
Darker grey indicates user input. 
MAX2310 HighBand Tank Design and Tuning Range  
Total Tank Capacitance vs. V tune  
V tune

Total C  Ct
(Nominal) 
Ct (Low) 
Ct (High) 

0.5V

Ct high  10.4968pF  10.0249pF  10.9126pF  
1.375V

Ct mid  9.6292pF  8.8913pF  10.2124pF  
2.2V

Ct low  8.6762pF  7.7872pF  9.3717pF  
Tank Components 


C coup

12pF

0.1pF

1%


C cent

3.4pF

0.1pF

3%


C stray

0.70pF


L

18nH

2.00%


C int

0.954pF

10.00%


Parasitics and Pads (C stray)  
Due to Q 
C L

0.01pF


Ind. pad 
C Lp

1.13pF


Due to  

0.036pF


Var. pad 
C vp

0.82pF


Varactor Specs  
Alpha SMV1255003  
Cjo 
82pF

Varactor Tolerance


Vj 
17V

0.5V

19.00%


M 
14

1.5V

29.00%


Cp 
0pF

2.5V

35.00%


Rs 
1Ω

Reactance


Ls 
1.7nH

X Ls

4.06  
Freq 
380.00MHz


Nominal Varactor 
X c

Net Cap


Cv high

54.64697pF

7.66426

116.1695pF


Cv mid

27.60043pF

15.1747

37.67876pF


Cv low

14.92387pF

28.0643

17.44727pF


Negative Tol Varactor (Low Capacitance)  
Cv high

44.26404pF

9.46205

77.51615pF


Cv mid

19.59631pF

21.3728

24.19031pF


Cv low

9.700518pF

43.1759

10.70708pF


Positive Tol Varactor (High Capacitance)  
Cv high

65.02989pF

6.44056

175.8588pF


Cv mid

35.60456pF

11.7633

54.36221pF


Cv low

20.14723pF

20.7884

25.03539pF


Nominal LO (Nom) Range 
Low Tol IF (High) Range 
Nominal IF (Nom) Range 
High Tol IF (Low) Range 

F low

366.15MHz

189.23MHz

183.07MHz

177.78MHz


F mid

382.29MHz

200.94MHz

191.14MHz

183.78MHz


F high

402.74MHz

214.71MHz

201.37MHz

191.84MHz


BW

36.59MHz

25.47MHz

18.29MHz

14.06MHz


% BW

9.57%

12.68%

9.57%

7.65%


Nominal IF Frequency 


Design
Constraints


Condition for bold number 
< IF

= IF

> IF


Delta 
0.77

1.14

1.84


Test 
pass

pass

pass


Raise or lower cent freq by 
1.14

MHz


Inc or dec BW 
2.61

MHz


Cent adj for min BW 
190.54

MHz


K vco 
21.52MHz/V

Light grey indicates calculated values. 
Darker grey indicates user input. 
MAX2310 HighBand Tank Design and Tuning Range  
Total Tank Capacitance vs. V tune  
V tune

Total C  Ct (Nominal) 
Ct (Low) 
Ct (High)  
0.5V

Ct high  8.8304pF  8.1465pF  9.4877pF  
1.35V

Ct mid  7.9221pF  7.0421pF  8.6970pF  
2.2V

Ct low  6.9334pF  5.9607pF  7.7653pF  
Tank Components 


C coup

12pF

0.6pF

5%


C cent

1.6pF

0.1pF

6%


C stray

0.70pF


L

18nH

2.00%


C int

0.959pF

10.00%


Parasitics and Pads (C stray)  
Due to Q 
C L

0.1pF


Ind. pad 
C Lp

1.13pF


Due to  
C diff

0.036pF


Var. pad 
C vp

0.82pF


Varactor Specs  
Alpha SMV1255003  
Cjo 
82pF

Varactor Tolerance


Vj 
17V

0.5V

19.00%


M 
14

1.5V

29.00%


Cp 
0pF

2.5V

35.00%


Rs 
1Ω

Reactance


Ls 
1.7nH

X Ls

4.49  
Freq 
420.00MHz


Nominal Varactor 
X
c

Net
Cap


Cv high

54.64697pF

6.93433

154.787pF


Cv mid

27.60043pF

13.7295

40.99616pF


Cv low

14.92387pF

25.3916

18.12647pF


Negative Tol Varactor (Low Capacitance)  
Cv high

44.26404pF

8.56091

92.99806pF


Cv mid

19.59631pF

19.3373

25.51591pF


Cv low

9.700518pF

39.0639

10.95908pF


Positive Tol Varactor (High Capacitance)  
Cv high

65.02989pF

5.82717

282.5852pF


Cv mid

35.60456pF

10.643

61.54791pF


Cv low

20.14723pF

18.8086

26.45795pF


Nominal LO (Nom) Range 
Low Tol IF (High) Range 
Nominal IF (Nom) Range 
High Tol IF (Low) Range 

F low

399.20MHz

209.92MHz

199.60MHz

190.67MHz


F mid

421.47MHz

225.78MHz

210.73MHz

199.14MHz


F high

450.52MHz

245.41MHz

225.26MHz

210.75MHz


BW

51.31MHz

35.49MHz

25.66MHz

20.09MHz


% BW

12.18%

15.72%

12.18%

10.09%


Nominal IF Frequency 


Design
Constraints


condition for bold number 
< IF

= IF

> IF


Delta 
0.08

0.73

0.75


Test 
pass

pass

pass


Raise or lower cent freq by 
0.73

MHz


Inc or dec BW 
0.83

MHz


Cent adj for min BW 
210.34

MHz


K vco 
30.18MHz/V

Light grey indicates calculated values. 
Darker grey indicates user input. 
MAX2310 HighBand Tank Design and Tuning Range  
Total Tank Capacitance vs. V tune  
V tune

Total C  Ct (Nominal) 
Ct (Low) 
Ct (High)  
0.5V

Ct high  5.8856  5.5289  6.2425  
1.375V

Ct mid  5.2487  4.9113  5.5858  
2.2V

Ct low  4.8371  4.5156  5.1581  
Tank Components


C coup

15pF

0.75pF

5%


C cent

1.6pF

0.1pF

6%


C stray

0.77pF


L

27

2.00%


C int

0.959

10.00%


Parasitics and Pads (C stray)  
Due to Q 
C L

0.17pF


Ind. pad 
C Lp

1.13pF


Due to  
C diff

0.036pF


Var. pad 
C vp

0.82pF


Varactor Specs  
Alpha SMV1763079  
Cjo 
8.2pF

Varactor Tolerance


Vj 
15V

0.5V

7.50%


M 
9.5

1.5V

9.50%


Cp 
0.67pF

2.5V

11.50%


Rs 
0.5Ω

Reactance


Ls 
0.8nH

X Ls

2.11  
Freq 
420.00MHz


Nominal Varactor 
X
c

Net
Cap


Cv high

6.67523pF

56.7681

6.933064pF


Cv mid

4.23417pF

89.4958

4.336464pF


Cv low

2.904398pF

130.471

2.952167pF


Negative Tol Varactor (Low Capacitance)  
Cv high

6.174588pF

61.3709

6.39456pF


Cv mid

3.831924pF

98.8904

3.915514pF


Cv low

2.570392pF

147.425

2.607736pF


Positive Tol Varactor (High Capacitance)  
Cv high

7.175873pF

52.8076

7.474698pF


Cv mid

4.636416pF

81.7313

4.759352pF


Cv low

3.238404pF

117.015

3.297904pF


Nominal LO (Nom) Range 
Low Tol IF (High) Range 
Nominal IF (Nom) Range 
High Tol IF (Low) Range 

F low

399.25MHz

208.05MHz

199.62MHz

191.92MHz


F mid

422.78MHz

220.75MHz

211.39MHz

202.89MHz


F high

440.40MHz

230.22MHz

220.20MHz

211.14MHz


BW

41.15MHz

22.16MHz

20.58MHz

19.21MHz


% BW

9.73%

10.04%

9.73%

9.47%


Nominal IF Frequency 


Design
Constraints


Condition for bold number 
< IF

= IF

> IF


Delta 
1.95

1.39

1.14


Test 
pass

pass

pass


Raise or lower cent freq by 
1.39

MHz


Inc or dec BW 
3.08

MHz


Cent adj for min BW 
209.60

MHz


K vco 
24.21MHz/V

EQN7

Alpha SMV1255003  Alpha SMV1763079 
C_{jo} = 82 pF  C_{jo} = 8.2 pF 
V_{j} =17 V  V_{j} =15 V 
M = 14  M = 9.5 
C_{p} = 0  C_{p} = 0.67 
R_{s} = 1Ω  R_{s} = 0.5Ω 
L_{s} = 1.7 nH  L_{s} = 0.8 nH 
EQN8

Frequency (MHz)  C_{int} (pF)  Frequency (MHz) (cont.)  C_{int} (pF) (cont.) 
100  0.708  360  0.949 
110  0.759  370  0.955 
120  0.800  380  0.954 
130  0.809  390  0.954 
140  0.839  400  0.954 
150  0.822  410  0.955 
160  0.860  420  0.959 
170  0.869  430  0.956 
180  0.880  440  0.959 
190  0.905  450  0.964 
200  0.917  460  0.962 
210  0.920  470  0.963 
220  0.926  480  0.963 
230  0.924  490  0.960 
240  0.928  500  0.964 
250  0.935  510  0.965 
260  0.932  520  0.968 
270  0.931  530  0.966 
280  0.933  540  0.968 
290  0.927  550  0.967 
300  0.930  560  0.974 
310  0.933  570  0.977 
320  0.943  580  0.976 
330  0.944  590  0.984 
340  0.945  600  0.982 
350  0.956     
Frequency (MHz)  C_{int} (pF)  Frequency (MHz) (cont.)  C_{int} (pF) (cont.) 
100  0.550  360  1.001 
110  0.649  370  0.982 
120  0.701  380  0.992 
130  0.764  390  1.001 
140  0.762  400  0.985 
150  0.851  410  0.980 
160  0.838  420  0.986 
170  0.902  430  0.992 
180  0.876  440  0.994 
190  0.907  450  1.001 
200  0.913  460  1.003 
210  0.919  470  1.007 
220  0.945  480  0.992 
230  0.952  490  1.010 
240  0.965  500  1.004 
250  0.951  510  1.011 
260  0.954  520  1.022 
270  0.974  530  1.019 
280  0.980  540  1.044 
290  0.973  550  1.026 
300  0.982  560  1.041 
310  0.970  570  1.038 
320  0.982  580  1.032 
330  0.991  590  1.036 
340  0.993  600  1.025 
350  0.991     
Related Parts  
MAX2306  CDMA IF VGAおよびI/Q復調器、VCOおよび合成付  Free Samples 
MAX2308  CDMA IF VGAおよびI/Q復調器、VCOおよび合成付  Free Samples 
MAX2309  CDMA IF VGAおよびI/Q復調器、VCOおよび合成付  Free Samples 
MAX2310  VCOおよびシンセサイザ付き、CDMA IF VGAおよびI/Q復調器  
MAX2312  VCOおよびシンセサイザ付き、CDMA IF VGAおよびI/Q復調器  
MAX2314  VCOおよびシンセサイザ付き、CDMA IF VGAおよびI/Q復調器  
MAX2316  VCOおよびシンセサイザ付き、CDMA IF VGAおよびI/Q復調器 
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Unknown: Sep 30, 2002
UNKNOWN 3256), AN530, AN 530, APP530, Appnote530, Appnote 530 