SP5055
2.6GHz Bidirectional I
2
C BUS Controlled Synthesiser
DS2361
ISSUE 4.5
November 2001
Ordering Information
SP5055GS/KG/MPAS (Tubes)
SP5055GS/KG/MPAD (Tape & Reel)
16lead minature plastic package
The SP5055 is a single chip frequency synthesiser designed
for TV tuning systems. Control data is entered in the standard
I
2
C BUS format. The device contains 4 addressable current
limited outputs and 4 addressable Bi-Directional open collector
ports one of which is a 3 bit ADC. The information on these
ports can be read via the I
2
C BUS. The device has one fixed
I
2
C BUS address and 3 programmable addresses, programmed
by applying a specific input voltage to one of the current limited
outputs. This enables 2 or more synthesisers to be used in a
system.
FEATURES
s
Complete 2.6GHz Single Chip System
s
Programmable via I
2
C BUS
s
Low power consumption (5V 65mA)
s
Low Radiation
s
Phase Lock Detector
s
Varactor Drive Amp Disable
s
6 Controllable Outputs, 4 Bi-Directional
s
5 Level ADC
s
Variable I
2
C BUS Address For Multi Tuner Applications
s
Full ESD Protection*
* Normal ESD handling procedures should be observed.
APPLICATIONS
s
Satellite TV
s
High IF Cable Tuning Systems
1
8
CHARGE PUMP
CRYSTAL Q1
CRYSTAL Q2
SDA
SCL
I/O PORT P7
* I/O PORT P6
I/O PORT P5
MP16
16
9
DRIVE OUTPUT
V
EE
RF INPUT
RF INPUT
V
CC
P0 OUTPUT PORT
PORT P3/ADD SELECT
I/O PORT P4
SP
5055S
= Logic level I/O
* = 3-bit ADC input
Fig. 1 Pin connections top view
2
SP5055
ELECTRICAL CHARACTERISTICS
T
amb
= -20
C to +80
C, V
CC
= +4.7V to 5.3V.
These Characteristics are guaranteed by either production test or design. They apply within the specified ambient
temperature and supply voltage unless otherwise stated. Reference frequency = 4MHz unless otherwise stated.
V
CC
= 5V
500MHz to 2.6GHz Sinewave
120MHz, see Fig. 5
Input voltage = V
CC
Input voltage = 0V
When V
CC
= 0V
I
sink
= 3mA
Byte 4, bit 2 = 0, pin 1 = 2V
Byte 4, bit 2 = 1, pin 1 = 2V
Byte 4, bit 4 = 1, pin 1 = 2V
V
pin 16
= 07V
V
OUT
= 12V
V
OUT
= 132V
V
OUT
= 0.7V
V
OUT
= 132V
V
pin 10
= 13.2V
V
pin 10
= 0V
See Table 3 for ADC Levels
Supply current
Prescaler input voltage
Prescaler input voltage
Prescaler input impedance
Prescaler input capacitance
SDA, SCL
Input high voltage
Input low voltage
Input high current
Input low current
Leakage current
SDA
Output voltage
Charge pump current low
Charge pump current high
Charge pump output leakage current
Charge pump drive output current
Charge pump amplifier gain
Recommended crystal series resistance
Crystal oscillator drive level
Crystal oscillator negative resistance
Output Ports
P0, P3 sink current
P0, P3 leakage current
P4-P7 sink current
P4-P7 leakage current
Input Ports
P3 input current high
P3 input current low
P4,P5,P7 input voltage low
P4,P5,P7 input voltage high
P6 input current high
P6 input current low
12
13, 14
13, 14
13, 14
4, 5
4, 5
4, 5
4, 5
4, 5
4
1
1
1
16
2
2
10, 11
10, 11
9-6
9-6
10
10
9,8,6
9,8,6
7
7
Typ.
Value
Conditions
Characteristic
Pin
50
100
3
0
500
10
750
0.7
10
2.7
65
50
2
50
170
6400
80
1
80
300
300
5.5
1.5
10
-10
10
0.4
5
200
1.5
10
10
+10
-10
0.8
+10
-10
Units
Min.
Max.
mA
mV
RMS
mV
RMS
pF
V
V
A
A
A
V
A
A
nA
A
mVp-p
mA
A
mA
A
A
A
V
V
A
A
3
SP5055
FUNCTIONAL DESCRIPTION
The SP5055 is programmed from an I
2
C BUS. Data and
Clock are fed in on the SDA and SCL lines respectively as
defined by the I
2
C BUS format. The synthesiser can either
accept new data (write mode) or send data (read mode).
The Tables in Fig. 3 illustrate the format of the data. The
device can be programmed to respond to several addresses,
which enables the use of more than one synthesiser in an I
2
C
Bus system. Table 4 shows how the address is selected by
applying a voltage to P3. The last bit of the address byte
(R/W) sets the device into read mode if it is high and write
mode if it is low. When the SP5055 receives a correct
address byte it pulls the SDA line low during the acknowledge
period and during following acknowledge periods after further
data bytes are programmed. When the SP5055 is
programmed into the read mode the controlling device
accepting the data must pull down the SDA line during the
following acknowledge period to read another status byte.
WRITE MODE (FREQUENCY SYNTHESIS)
When the device is in the write mode Bytes 2 + 3 select
the synthesised frequency while bytes 4 + 5 select the output
port states and charge pump information.
Once the correct address is received and acknowledged,
the first Bit of the next Byte determines whether that byte is
interpreted as byte 2 or 4, a logic 0 for frequency information
and a logic 1 for charge pump and output port information.
Additional data bytes can be entered without the need to
re-address the device until an I
2
C stop condition is recognised.
This allows a smooth frequency sweep for fine tuning or AFC
purposes.
If the transmission of data is stopped mid-byte (i.e., by
another device on the bus) then the previously programmed
byte is maintained.
Frequency data from bytes 2 and 3 is stored in a 15-bit
shift register and is used to control the division ratio of the 15-
bit programmable divider which is preceded by a divide-by-
16 prescaler and amplifier to give excellent sensitivity at the
local oscillator input; see Fig 5. The input impedance is shown
in Fig 7.
The programmed frequency can be calculated by
multiplying the programmed division ratio by 16 times the
comparison frequency F
comp
.
When frequency data is entered, the phase comparator,
via the charge pump and varactor drive amplifier, adjusts the
local oscillator control voltage until the output of the
programmable divider is frequency and phase locked to the
comparison frequency.
The reference frequency may be generated by an external
source capacitively coupled into pin 2 or provided by an on-
board 4MHz crystal controlled oscillator.
Note that the comparison frequency is 78125kHz when
a 4MHz reference is used.
Bit 2 of byte 4 of the programming data (CP) controls the
current in the charge pump circuit, a logic 1 for
170
A and
a logic 0 for
50
A, allowing compensation for the variable
tuning slope of the tuner and also to enable fast channel
changes over the full band. Bit 4 of byte 4 (T0) disables the
charge pump if set to a logic 1. Bit 8 of byte 4 (OS) switches
the charge pump drive amplifier's output off when it is set to
a logic 1. Bit 3 of Byte 4 (T1) selects a test mode where the
phase comparator inputs are available on P6 and P7, a
logic 1 connects F
comp
to P6 and F
div
to P7.
Byte 5 programs the output ports P0 to P7; on a logic 0 for
a high impedance output, logic 1 for low impedance (on).
READ MODE
When the device is in the read mode the status data read
from the device on the SDA line takes the form shown in Table
2.
Bit 1 (POR) is the power-on reset indicator and is set to a
logic 1 if the power supply to the device has dropped below 3V
and the programmed information lost (e.g., when the device is
initially turned on). The POR is set to 0 when the read sequence
is terminated by a stop command. The outputs are all set to high
impedance when the device is initially powered up. Bit 2 (FL)
indicates whether the device is phase locked, a logic 1 is
present if the device is locked and a logic 0 if the device is
unlocked.
6 BIT LATCH
PORT
INFORMATION
PRESCALER
4
16
PRE
AMP
15 BIT
PROGRAMMABLE
DIVIDER
F
div
F
comp
DIVIDER
4
512
OSC
4MHz
Q1
CRYSTAL
Q2
LOCK
DET
CHARGE
PUMP
CONTROL
DATA
LATCH
T0 CP
POWER ON
DETECTOR
I
2
C BUS
TRANSCEIVER
OS
LOGIC
GATE
PHASE
COMP
F
15 BIT LATCH
DIVIDER RATIO
P0 P3 P4 P5 P6 P7
ADDRESS
SELECT
3 BIT
ADC
3 TTL
LEVEL
COMP
CHARGE
PUMP
DRIVE/
VARICAP
OUT
V
CC
V
EE
SDA
SCL
RF IN
RF IN
15
12
16
1
3
2
13
14
5
4
11 10
9
8
7
6
Fig. 2 Block diagram
4
SP5055
A0
0
1
0
1
0
Voltage input to P6
0.6V
CC
to 13.2V
045V
CC
to 06V
CC
03V
CC
to 045V
CC
015V
CC
to 03V
CC
0 to 0.15V
CC
Bits 3, 4 and 5 (I2,I1,I0) show the status of the I/O Ports P7,
P5 and P4 respectively. A logic 0 indicates a low level and a
logic 1 a high level. If the ports are to be used as inputs they
should be programmed to a high impedance state (logic 1).
These inputs will then respond to data complying with TTL type
voltage levels. Bits 6, 7 and 8 (A2,A1,A0) combine to give the
output of the 5 level ADC.
The 5 level ADC can be used to feed AFC information to
the microprocessor from the IF section of the receiver, as
illustrated in the typical application circuit.
APPLICATION
A typical Application is shown in Fig. 4. All input/output
interface circuits are shown in Fig. 6.
Table 1 Write data format (MSB transmitted first)
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Address
Programmable divider
Programmable divider
Charge pump and test bits
I/O port control bits
1
2
14
2
6
CP
P6
0
2
13
2
5
T1
P5
0
2
12
2
4
T0
P4
0
2
11
2
3
1
P3
MA0
2
9
2
1
1
X
MA1
2
10
2
2
1
X
A
A
A
A
A
MSB
1
0
2
7
1
P7
LSB
0
2
8
2
0
OS
P0
Table 2 Read data format (MSB is transmitted first)
Byte 1
Byte 2
Address
Status byte
1
FL
0
I2
0
I1
0
I0
MA0
A1
MA1
A2
A
A
1
POR
1
A0
A
: Acknowledge bit
MA1, MA0
: Variable address bits (see Table 4)
CP
: Charge Pump current select
T1
: Test mode selection
T0
: Charge pump disable
OS
: Varactor drive Output disable Switch
P7, P6, P5, P4,
: Control output states
P3, P0
POR
: Power On Reset indicator
FL
: Phase lock detect flag
I2, I1, I0
: Digital information from Ports P7, P5 and P4, respectively
A2, A1, A0
: 5 Level ADC data from P6 (see Table 3)
X
: Don't care
Table 4 Address selection
MA0
0
1
0
1
MA1
0
0
1
1
Voltage input to P3
0V to 02V
CC
Always valid
03V
CC
to 07V
CC
08V
CC
-13.2V
A1
0
1
1
0
0
A2
1
0
0
0
0
Table 3 ADC levels
Fig. 3 Data formats
5
SP5055
9
10
11
12
13
16
16
15
8
7
6
5
4
3
1
2
1n
1n
18p
180n
39n
22k
0.1
4MHz
CRYSTAL
P4
P5
P6
P7
SCL
SDA
P3
P0
IF SIGNAL
+5V
+12V
+30V
22k
2N3904
AFC OUTPUT
I2C BUS
VARICAP
INPUT
OSCILLATOR
OUTPUT
VT
IF SECTION
CONTROL
MICRO
SATELLITE
TUNER
SP
5055S
APPLICATION
A typical application is shown in Fig. 4. All input/output interface circuits are shown in Fig. 6.
Fig. 5 Typical input sensitivity
FREQUENCY (MHz)
OPERATING
WINDOW
1000
120
500
2000
3000
2600
100
50
150
3000
V
IN
(mV RMS INTO 50
)
Fig. 4 Typical application
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