lc72130m Sanyo Semiconductor Corporation, lc72130m Datasheet - Page 16

• Manufacturer Part Number: lc72130m
• Description: Am/fm Pll Frequency Synthesizer
• Manufacturer: Sanyo Semiconductor Corporation

IF Counter
The LC72130 IF counter is a 20-bit binary counter. The result, i.e., the counter’s msb, can be read serially from the DO pin.
The IF frequency (Fc) is measured by determining how many pulses were input to an IF counter in a specified
measurement period, GT.
Fc =
1. IF Counter Frequency Calculation Examples
GT1
0
0
1
1
• When the measurement period (GT) is 32 ms, the count (C) is 53980 hexadecimal (342400 decimal):
• When the measurement period (GT) is 8 ms, the count (C) is E10 hexadecimal (3600 decimal):
GT
IF frequency (Fc) = 342400 32 ms = 10.7 MHz
IF frequency (Fc) = 3600 8 ms = 450 kHz
C
GT0
0
1
0
1
Measurement period (GT) (ms)
(C = Fc GT)
32
64
4
8
Measurement time
Wait time (twu) (ms)
C: Count value (number of pulses)
LC72130, 72130M
3 to 4
3 to 4
7 to 8
7 to 8
No. 4973-16/22