LC72121V(1998) 查看數據表（PDF） - SANYO -> Panasonic

零件编号

产品描述 (功能)

生产厂家

LC72121V
(Rev.:1998)

PLL Frequency Synthesizers for Electronic Tuning

SANYO -> Panasonic 

LC72121, 72121M, 72121V

Structure of the IF Counter

The LC72121 IF counter is a 20-bit binary counter, and takes the IF signal from the IFIN pin as its input. The result of

the count can be read out serially, MSB first, from the DO pin.

Measurement time

GT1

GT0

Measurement time (GT)

Wait time (tWU)

0

0

4 ms

3 to 4 ms

0

1

8

3 to 4 ms

1

0

32

7 to 8 ms

1

1

64

7 to 8 ms

The IF frequency (Fc) is measured by determining how many pulses were input to the IF counter in the stipulated

measurement time, GT.

Fc =—C— (C = Fc x GT)

GT

C: Counted value (the number of pulses)

IF Counter Frequency Measurement Examples

• When the measurement time (GT) is 32 ms and the counted value (C) is 53980 (hexadecimal) or 342,400 decimal.

IF frequency (FC) = 342400 ÷ 32 ms = 10.7 MHz

• When the measurement time (GT) is 8 ms and the counted value (C) is E10 (hexadecimal) or 3600 decimal.

IF frequency (FC) = 3600 ÷ 8 ms = 450 kHz

No. 5815-15/22

Share Link: