SKY73126-31 Datasheet, PDF (7/14 Pages) Skyworks Solutions Inc. – 161.92 MHz High Performance VCO/Synthesizer

DATA SHEET • SKY73126-31 VCO/SYNTHESIZER
Table 7. Word 3: Frequency Control Hold Register (2 of 2)
Parameter
Function
State Description
cp_delay
rsvd
Charge pump delay [23:21]
Reserved [31:24]
Bits [23:21]:
0 0 0 = 0.5 ns
0 0 1 = 0.7 ns
0 1 0 = 0.9 ns
0 1 1 = 1.2 ns
1 0 0 = 1.4 ns
1 0 1 = 1.7 ns
1 1 0 = 2.0 ns
1 1 1 = 3.0 ns
Reserved
Recommended
Operational Value
(Binary)
000
Default Value
(Binary)
000
00000000
00000000
CLK
DATA
LE
LD
t2
t1
D31=1 D30=x
t6
t3 t4
D4=x D3=0 D2=0 D1=0 D0=0
t6
t5
Default
tdout
ID31 ID30
Figure 5. Vendor ID Read-Back Timing Diagram
ID1
ID0
Default
S1193
D31 D30 D29 D28 D27 D26 D25 D24 D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
1 x x x x x x x x x x x x x x x x x x x x x x x x x x x0000
Figure 6. Vendor ID Read-Back Initialization Word
VCO Prescalers
The VCO prescalers divide the VCO output signal by either 16/17
or 8/9. The modulus control signal from the N-counter determines
whether to divide by 16 or 17 in 16/17 mode, or whether to divide
by 8 or 9 in 8/9 mode. The prescaler mode is determined by
bit [17] of Word 1 (Operation Mode Register). The maximum
prescaler input frequency is 2000 MHz for 8/9 mode, and
3100 MHz for 16/17 mode.
N-Counter
The N-counter consists of two asynchronous ripple counters, a
12-bit M-counter and a 4-bit A-counter. The M-counter
determines the counts using the lower division ratio in the
prescaler (8 or 16); the A-counter determines the counts using the
upper division ratio (9 or 17).
The value of the N-counter is determined by the equation:
(M × P) + A
where M and A are the values of the M-counter and A-counter,
and P = 8 for 8/9 mode or 16 for 16/17 mode.
In 16/17 mode, the M-counter (bits [11:0]) value is determined by
the 12 highest order bits of the N-counter (bits [15:4]). The A-
counter value (bits [3:0]) is determined by the 4 lowest order bits
of the N-counter (bits [3:0]).
In 8/9 mode, the M-counter value is determined by bits [14:3] of
the N-counter and the A-counter value is determined by the three
lowest order bits of the N-counter (bits [2:0]). In this case, bit [15]
of the N-counter is always cleared.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201112C • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • February 24, 2010
7