S1M8836 Samsung Semiconductor, Inc., S1M8836 Datasheet - Page 24

• Manufacturer Part Number: S1M8836
• Manufacturer: Samsung Semiconductor, Inc.

S1M8836/37
PULSE SWALLOW FUNCTION
The RF VCO frequency f VOC becomes N INT + N FRAC times the comparison frequency(f OSC /R) where
N INT is the integer divide ratio and N FRAC is the fractional component;
f VCO : External VCO output frequency
f OSC : External reference frequency(From external oscillator)
R: Preset divide ratio of programmable R counter (RF: 1, 2, 3(typically 2), IF: 3 to 32767);
P: Preset modulus of quadruple modulus prescaler (S1M8836 RF:P=8, S1M8837 RF:P=16, IF:P=8)
B: Preset value of main counter (S1M8836/37 RF: 3 to 127, IF: 3 to 4095)
A: Preset value of swallow counter division ratio
N FRAC : Fractional component of Pulse-swallowed division ratio N (for IF: NFRAC = 0)
F: Preset value of fractional register(-31488
For examples in S1M8836 fractional-N mode (f OSC =19.68MHz, R=2, P=8)
1) for fvco = 955.02MHz; N = 97.05487805, B=12, A=1, F=3456 (= 0 0000 1101 1000 0000)
2) for fvco = 955.03MHz; N = 97.05589431, B=12, A=1, F=3520
3) for fvco = 956.25MHz; N = 97.17987805, B=12, A=1, F=11328
4) for fvco = 979.35MHz; N = 99.52743902, B=12, A=4, F=-29760
For examples in S1M8837 fractional-N mode (fosc=19.68MHz, R=2, P=16)
1) for fvco = 1620.87MHz(CH25) ; N = 164.722561, B=10, A=5, F=-17472 (= 1 1011 1011 1100 0000)
2) for fvco = 1620.88MHz
3) for fvco = 1622.12MHz(CH50) ; N = 164.8495935, B=10, A=5, F=-9472
4) for fvco = 1632.12MHz(CH250) ; N = 165.8658537, B=10, A=6, F=-8448
5) for fvco = 1648.37MHz(CH575) ; N = 167.5172764, B=10, A=8, F=-30400
24
f VCO = (N INT + N FRAC )
where N INT = P
RF PLL: N FRAC = F/62976, -31488
IF PLL: N FRAC = 0, B > A and 3
(S1M8836 RF: 0
complementary binary code.
A
B + A
7, S1M8837 RF: 0
f OSC /R = N
; N = 164.7235772, B=10, A=5, F=-17408
R
F
32767
F
f OSC /R
31488, and R = 1, 2, 3 (typically 2)
A
31488 ); For a negative integer, F should be inputted as its 2's
15. IF: 0
A
7, A<B)
FRACTIONAL-N RF/INTEGER-N IF DUAL PLL