Philips Semiconductors
Product specification
1GHz low-voltage Fractional-N synthesizer
SA7025
BLOCK DIAGRAM
CLOCK
DATA
STROBE
SERIAL INPUT + PROGRAM LATCHES
V
DD
V
SS
EM
FB
2
RF
IN
RF
IN
64/65/72
PRESCALER
MAIN DIVIDERS
PR
2
NM1
12
NM2
NM3
8
FB
FMOD
NF
3
PRESCALER
MODULUS
CONTROL
RF
FRD
CN
RN
FRACTIONAL
ACCUMULATOR
TEST
EM
MAIN
PHASE
DETECTOR
2
8
NORMAL
OUTPUT
CHARGE
PUMP
CL
PHP
SPEED-UP
OUTPUT
CHARGE
PUMP
SM
2
NR
V
CCP
EM+EA
MAIN
REFERENCE
SELECT
2
12
CK
4
INTEGRAL
OUTPUT
CHARGE
PUMP
PHI
REF
IN
REFERENCE DIVIDER
÷2
÷2
÷2
SA
2
AUXILIARY
REFERENCE
SELECT
EA
PA
EA
12
NA
AUXILIARY
PHASE
DETECTOR
2
RA
AUXILIARY
OUTPUT
CHARGE
PUMP
PHA
LOCK
AUX
IN
1/4
PRESCALER
AUXILIARY DIVIDER
V
DDA
V
SSA
SR00601
Figure 2. Block Diagram
1996 Aug 6
4