lc72136nm Sanyo Semiconductor Corporation, lc72136nm Datasheet - Page 16

• Manufacturer Part Number: lc72136nm
• Description: Pll Frequency Systhesizer
• Manufacturer: Sanyo Semiconductor Corporation

IF Counter Structure
The LC72136N IF counter is a 20-bit binary counter. The result of the count can be read out serially, MSB first, from the
DO pin.
IF frequency (Fc) measurement consists of determining how many pulses enter the IF counter in a specified
measurement time (GT).
Sample IF Counter Frequency Calculations
1. For a measurement time (GT) of 32 ms and a count value (C) of 53980 (hexadecimal), which is 342,400 (decimal)
2. For a measurement time (GT) of 8 ms and a count value (C) of E10 (hexadecimal), which is 3600 (decimal)
GT1
0
0
1
1
Fc =
IF frequency (Fc) = 342,400 ÷ 32 ms = 10.7 MHz
IF frequency (Fc) = 3600 ÷ 8 ms = 450 kHz
GT
GT0
C
0
1
0
1
Measurement period (GT) (ms)
(C = Fc GT)
32
64
4
8
Measurement time
Wait time (t
LC72136N, 72136NM
C: count value (number of pulses)
3 to 4
3 to 4
7 to 8
7 to 8
WU
) (ms)
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