PIN ASSIGNMENT
BLOCK DIAGRAM
PIN DESCRIPTION
FUNCTION DESCRIPTIONS
Pulse swallow function
The divide ratio can be calculated using the following equation:
fVCO = [(M x N) + A] x fOSC P R (A < N)
fVCO : Output frequency of external voltage controlled oscillator (VCO)
N : Preset divide ratio of binary 11-bit programmable counter (16 to 2,047)
A : Preset divide ratio of binary 7-bit swallow counter (0 3 A 3 127)
fOSC : Output frequency of the reference frequency oscillator
R : Preset divide ratio of binary 14-bit programmable reference counter (8 to 16,383)
M : Preset divide ratio of modules prescaler (128)
Serial data input
Serial data is input using the Data, Clock, and LE pins. Serial data controls the 15-bit programmable reference divider and 18-bit
programmable divider separately.
Binary serial data is input to the Data pin.
One bit of data is shifted into the internal shift registers on the rising edge of the clock. When the load enable pin is high or open, stored
data is latched depending on the control data as follows:
(a) Programmable reference divider ratio
The programmable reference divider consists of a 15-bit latch and a 14-bit reference counter. The serial 16-bit data format is
shown below:
(b) Programmable divider divide ratio
The programmable divider consists of a 19-bit shift register, an 18-bit latch, a 7-bit swallow counter, and an 11-bit programmable
counter. The serial 19-bit data format is shown below:
Serial data input timing
Intermittent operation
Intermittent operation limits power consumption by shutting down or start the internal circuits according to its necessity. If device
operation resumes uncontrolled, the error signal output from the phase comparator may exceed the limit due to an undefined phase
relationship between the reference frequency (fR) and the comparison frequency (fP) and frequency lock is lost.
To prevent this, an intermittent operation control circuit is provided to decrease the variation in the locking frequency by forcibly
correcting phase of both frequencies to limit the error signal output. This is done by the PS control circuit. If PS is set high, the circuit
enter the operating mode. If PS is set low, operation stops and the device enters the stand-by mode. Each mode is explained below:
Relationship between the FC input and phase characteristics
The FC pin changes the phase characteristics of the phase comparator. The internal charge pump output level (DO) is reversed, depending on the FC pin input level. The relationship between the FC input level and DO is shown below:
When designing a synthesizer, the FC pin setting depends on the VCO characteristics.
Phase comparator output waveform (FC = High)
Analog switch
The LE signal turns the analog switch on or off. When the analog switch is turned on, the charge pump output (DO) is output through the BiSW pin. When it is turned off, the BiSW pin is in the high-impedance state.
When LE = high (when the divide ratio of the internal divider is changed): Analog switch = on
When LE = low (normal operating mode): Analog switch = off
The LPF time constant can be decreased by inserting an analog switch between LPF1 and LPF2. This decreases the lock-up time when the PLL channel is changed.
RECOMMENDED OPERATING CONDITIONS
Notes: To protect against damage by electrostatic discharge, note the following handling precautions:
- Store and transport devices in conductive containers.
- Use properly grounded workstations, tools, and equipment.
- Turn off power before inserting or removing this device a socket.
- Protect leads with conductive sheet, as treatment (transport) a board mounted the device.
ELECTRICAL CHARACTERISTICS
TEST CIRCUIT
(FOR MEASURING PRESCALER INPUT SENSITIVITY)
APPLICATION EXAMPLE
PACKAGE DIMENSIONS
For further information please contact:
Japan
FUJITSU LIMITED
Electronic Devices
International Operations Department
KAWASAKI PLANT, 1015 Kamikodanaka,
Nakahara-ku, Kawasaki-shi,
Kanagawa 211, Japan
Tel: (044) 754-3753
FAX: (044) 754-3332
North and South America
FUJITSU MICROELECTRONICS, INC.
Semiconductor Division
3545 North First Street
San Jose, CA 95134-1804, USA
Tel: (408) 922-9000
FAX: (408) 432-9044/9045
Europe
FUJITSU MIKROELEKTRONIK GmbH
Am Siebenstein 6-10,
63303 Dreieich-Buchschlag,
Germany
Tel: (06103) 690-0
FAX: (06103) 690-122
Asia Pacific
FUJITSU MICROELECTRONICS ASIA PTE LIMITED
No.51 Bras Basah Road,
Plaza By The Park,
#06-04 to #06-07
Singapore 0718
Tel: 336-1600
FAX: 336-1609