MB15C03 Fujitsu, MB15C03 Datasheet - Page 14

• Manufacturer Part Number: MB15C03
• Description: Single Serial Input PLL Frequency Synthesizer On-Chip prescaler
• Manufacturer: Fujitsu

14
MB15C03
Since the divide rations are unpredictable when the MB15C03 is turned on, it is necessary to initialize the divide
ratio for both dividers at power-on time. As shown in Figure 6, after setting the divide ratio for one of the dividers
(e.g., programmable reference divider), set LE to “H” level before setting the divide ratio for the other divider
(e.g., programmable divider). To change the divide ratio of one of the dividers after initialization, input the serial
data only for that divider (the divide ratio for the other divider is preserved).
Clock
Data
LE
Data
Clock
LE
Serial data for programmable
reference divider
Figure 6
16 clocks
t
1
Figure 5 Serial data input timing
Inputting serial data (Setting divisors)
t
2
C
t
3
Serial data for programmable
divider
20 clocks
t
4
t
5
* : Control bit(2 bits)
C