UMA1005T Philips Semiconductors (Acquired by NXP), UMA1005T Datasheet - Page 9

• Manufacturer Part Number: UMA1005T
• Description: Dual Low-power Frequency Synthesizer
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
Table 2 Selection of prescaler ratio
Notes
1. X = don’t care.
2. When the fractional accumulator overflows.
The total division ratio from prescaler to the phase detector expressions are given in Table 3.
Table 3 Total division from prescaler to phase detector expressions
Note
1. When the fractional accumulator overflows.
When the prescaler ratio is R2 = R1 + 1 the total division ratio N = N + 1.
Table 4 Modulus prescaler
November 1994
( NM1
( NM1
1 to NM2
0 to NM2
0 to NM3
0 to NM4
PR = 01
PR = 10
PR = 11
PR = 00
Dual low-power frequency synthesizer
CONDITION
COUNTER
STATUS
PR
00
01
10
11
1) to 0
1) to 1
N = (NM1 + 2)
N = (NM1 + 1)
N = (NM1 + 2)
N = (NM1 + 1)
N = (NM1 + 2)
N = (NM1 + 1)
N = (NM1 + 2)
N = (NM1 + 1)
MODULUS PRESCALER
FB1
1
1
0
0
0
1
4
2
3
4
R1 + NM2
R1 + NM2
R1 + NM2
R1 + NM2
R1 + (NM2 + 1)
R1 + (NM2 + 1)
R1 + (NM2 + 1)
R1 + (NM2 + 1)
R2
R2 + (NM3 + 1)
R2 + (NM3 + 1)
R2 + (NM4 + 1)
FB2
0
0
0
0
1
1
R2; note 1
R2 + (NM3 + 1)
R2 + (NM3 + 1)
R2 + (NM4 + 1)
NM1
9
12
12
12
12
EXPRESSION
R1
R1
R2
R2
R3; if PR = 1X
R4; if PR = 11 or 00
R3
R3 + (NM4 + 1)
R4
(2)
(2)
R3; note 1
R3 + (NM4 + 1)
R4; note 1
NM2
4
8
4
4
BIT CAPACITY
PRESCALER RATIO
R4
NM3
R4; note 1
4
4
Preliminary specification
UMA1005T
(1)
NM4
4
4