SP8853A/B
1·3GHz Professional Synthesiser
Supersedes March 1997 version, DS2352 - 3.0
DS2352 - 4.0 March 1998
The SP8853 is a low power single chip synthesiser
intended for professional radio applications, containing all the
elements (apart from the loop amplifier) required to build a PLL
frequency synthesis loop
The device is serially programmable by a three-wire data
highway and contains three independent buffers to store one
reference divider word and two local oscillator divider words.
A digital phase detector with two charge pumps,
programmable in phase and gain, are provided to improve
lock-up performance. The preset operation of the charge
pumps can be overwritten or the comparison frequencies
switched to output ports under control of the divider word. The
dual modulus ratio and so operating range is also
programmable through the same word.
A power down mode is incorporated as a battery economy
feature.
The SP8853 is specified at 1·3GHz at
255°C
to1125°C
(A
grade) and
240°C
to185°C
(B grade).
F
PD
*
LOCK DETECT
PD1 OUTPUT
V
EE
3
4
3
2
1
28
27 26
25
24
23
F
REF
*
POWER DOWN
V
EE
4
V
CC
4
V
CC
1
RF INPUT
RF INPUT
NC
Cd
IC
5
6
7
8
9
10
11
12
13
14
15
16
17 18
PD2 OUTPUT
RPD
V
CC
3
GROUND
XTAL 1
XTAL2
V
EE
2
SP8853
22
21
20
19
DATA
CLOCK
ENABLE
F1/F2
V
EE
1
NC
FEATURES
s
Improved Digital Phase Detector Eliminates
‘Dead Band’ Effects
s
Low Operating Power, Typically 175mW
s
1·3GHz Operating Frequency
s
Complete Phase Locked Loop
s
High Input Sensitivity
s
Programmed throughThree-Wire Bus
s
Wide Range of Reference Division Ratios
s
Local Storage for Two Frequency Words, giving
Rapid Frequency Toggling
s
Programmable Phase Detector Gain
s
Power Down Mode
ABSOLUTE MAXIMUM RATINGS
Supply voltage
Storage temperature
Prescaler input voltage
20·3V
to
17V
255°C
to
1150°C
2·5V p-p
V
CC
2
HC28
*F
PD
and F
REF
outputs are reversed by the phase
detector sense bit in the F1/F2 programming word. The
above diagram is correct when the sense bit is low. See
Table 2 and Fig. 7.
V
CC
1, V
EE
1 – preamplifier and prescaler supplies
V
CC
2, V
EE
2 – oscillator supplies
V
CC
3, V
EE
3 – charge pump 2 supplies
V
CC
4, V
EE
4 – ECL supplies
Fig. 1 Pin identification diagram (top view)
ORDERING INFORMATION
SP8853/A/HC
Military temperature range
SP8853/B/HC
Industrial temperature range
MITEL [ MITEL NETWORKS CORPORATION ]
