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U2733B-C Datasheet, PDF (1/14 Pages) TEMIC Semiconductors – Fractional-N Frequency Synthesizer for DAB Tuner
U2733B-C
Fractional-N Frequency Synthesizer for DAB Tuner
Description
The U2733B-C is a monolithically integrated
fractional-N frequency synthesizer circuit fabricated in
TEMIC’s advanced UHF5S technology. Designed for
applications in DAB receivers, it controls a VCO to
synthesize frequencies in the range of 70 to 500 MHz in
a 16 kHz raster; four different reference divide factors can
be selected. The lock status of the phase detector is
indicated at a special output pin, six switching outputs can
be addressed. An internal frequency doubler provides an
output signal having twice the frequency of the reference
oscillator. All functions of this IC are controlled by
I2C bus.
Features
D Microprocessor controlled via I2C bus
D 4 addresses selectable
D Four reference divide factors selectable:
1024, 1120, 1152, 1536
D Effectively
D Programmable 15-bit counter 1:2048 to 1:32767
effectively
D Three state phase detector with programmable charge
pump
D Superior phase noise performance
D Deactivation of tuning output programmable
D 6 switching outputs (open collector)
D Reference frequency doubler (open collector output)
D Lock status indication (open collector)
D Fully compatible to U2753B-C
D SSO20 package
Block Diagram
REF 4
5
NREF
18
RF
17
NRF
Frequency doubler
x2
FDO NFDO
10
9
Reference counter
Fractional N
control
Prog.
13 Bit counter
N/N=1
Three State
Phase
Detector
Lock detector
Prog.
charge pump
4 Bit latch
3
PLCK
1
PD
2
VD
7 Bit latch
2 Bit
latch
5 Bit latch
I2C Bus –Interface / Control
MUX
MUX
Switches
19
20
GND VS
6
7
8
11 12 13 14 15 16
ADR
SCL
SDA
SWC SWD SWE SWF SWG SWH
12476
Figure 1. Block diagram
TELEFUNKEN Semiconductors
1 (14)
Rev. A1, 21-Aug-96
Preliminary Information