SM5302A

NIPPON PRECISION CIRCUITS INC.—18

Note. A value other than 1.8k

Ω will change the current consumption, so caution should be taken to ensure the

power dissipation does not exceed the absolute maximum rating for the package.

Half fc Mode

In half fc mode, the CH-2 and CH-3 cutoff frequency is 1/2 that of the CH-1 cutoff frequency setting. Half fc

mode is useful for systems where the sampling frequency varies due to luminance (Y) and color difference sig-

nal (Cr, Cb) requirements as in digital component signals. Note in figure 2 that the cutoff frequency ratio for a

given cutoff frequency setting (FCDATA) is not constant.

Group Delay Characteristics

The group delay varies with the cutoff frequency setting, as shown in figure 3. Note also that in half fc mode,

the group delay between CH-1 and CH-2/CH-3 varies.

* Ratio of CH-2 and CH-3 cutoff frequency at half fc mode based on

CH-1 cutoff frequency.

40

45

50

0

32

64

96

128

160

192

224

256

0

5

10

15

20

25

30

35

FCDATA

Figure 2. Cutoff frequency ratio (half fc mode)

50%

52%

54%

56%

58%

60%

0

32

64

96

128

FCDATA

160 192 224 256

40%

42%

44%

46%

48%

HALF = High

Ω

Figure 3. Group delay characteristics

Frequency [MHz]

0

0

10

20

30

40

50

60

70

80

90

100

10

20

30

40

50

60

FCDATA = 227

FCDATA = 10