ZARLINK SL1935NP1Q

SL1935
Single Chip Synthesized Zero IF Tuner
April 2004
Features
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Ordering Information
Single chip synthesised tuner solution for quadrature
down conversion, L-band to Zero IF.
DVB compliant, operating dynamic range -70 to
-20dBm.
Compatible with DSS and DVB variable symbol rate
applications.
Selectable baseband path, programmable through
I2C bus.
Excellent quadrature balance up to 30MHz
baseband
Excellent immunity to spurious second harmonic
(RF and LO) mixing effects.
Low oscillator phase noise and reradiation.
High output referred linearity for low distortion and
multi channel application.
Integral fast mode compliant I2C bus controlled PLL
frequency synthesiser, designed for high comparison
frequencies and low phase noise performance.
Buffered crystal output for clocking QPSK
demodulator.
ESD protection (Normal ESD handling procedures
should be observed).
Satellite receiver systems.
•
Data communications systems.
XTALCAP
XTAL
SDA
SCL
BUFREF
VCCD
VCC
RF
RFB
VCC
IFIA
IFIB
VCC
OFIA
OFIB
VEE
IOUT
ADD
SL1935D/KG/NP1Q (Tape and Reel) 36 pin SSOP
Description
The SL1935 is a complete single chip I2C bus controlled
Zero IF tuner and operates from 950 to 2150MHz. It
includes an on-board low phase noise PLL frequency
synthesiser and low noise LNA/AGC. The SL1935 is
intended primarily for application in digital satellite Network
Interface Modules and performs the complete tuner
function.
The device contains all elements necessary, with the
exception of local oscillator tuning network and crystal
reference, to produce a high performance I(n-phase) &
Q(uadrature) downconversion tuner function. Due to the
high signal handling design the device does not require
any front end tracking filters.
The SL1935 includes selectable baseband signal paths,
allowing application with two externally definable filter
bandwidths, facilitating application in variable symbol
rate and simulcast systems. The SL1935 is optimised to
interface with the VP310 (ADC/QPSK/FEC) Satellite
Channel Decoder, available from Zarlink Semiconductor
and offers a full front end solution.
Applications
•
SL1935D/KG/NP1P (Tubes) 36 pin SSOP
1
18
36
19
PUMP
DRIVE
PORT P0
VEE
TANKS
TANKSB
VEE
TANKV
TANKVB
VEE
IFQA
IFQB
VCC
OFQA
OFQB
VEE
QOUT
AGCCONT
Figure 1. Pin connections
1
Zarlink Semiconductor Inc.
Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc.
Copyright 2003 - 2004, Zarlink Semiconductor Inc. All Rights Reserved.
SL1935
RFB RF
8
9
AGCCONT
19
23 OFQA
RF Section
VCC
7,10,13,24
VCCD
6
VEE
16,21,27,30,33
22 OFQB
AGC
Sender
RF section
26 IFQA
PLL section
25 IFQB
20 QOUT
BS
90deg
17 IOUT
TANKV 29
TANKVB 28
Frequency
Agile
Phase
Splitter
VCOV
TANKS 32
TANKSB 31
Divide
by 2
11 IFIA
12 IFIB
0deg
14 OFIA
VCOS
15 OFIB
PLL Section
VS BS
15 bit
Programmab le
Divider
36 PUMP
Fpd
Charge
Pump
35 DRIVE
SDA 3
I2C Bus Interface
SCL 4
34 POR T P0
ADD 18
XTAL 2
XTALCAP 1
REF
OSC
Fpd/2
Reference
Divider
Figure 2. Block diagram
2
5 BUFREF
Fcomp
SL1935
Table 1. Quick Reference Data
Characteristic
Value
950 to 2150
Operating range
-75 to -15
Input dynamic range
10
VSWR with input match
Input NF
10
@ -70dBm operating sensitivity
15
@ -60dBm operating sensitivity
+5
IPIP3 @ -20dBm operating sensitivity
+20
IPIP2@ -20dBm operating sensitivity
-5
IPP1dB@ -20dBm operating sensitivity
2.0
Baseband output limit voltage
0.2
Gain match up to 22MHz
0.7
Phase match up to 22MHz
1
Gain flatness up to 30MHz
Local oscillator phase noise
-80
SSB at 10kHz offset
<-70
In band LO reradiation from RF input
-55
LO second harmonic interference level at input level of
-20dBm per carrier
-35
LNA second harmonic interference level at input level
of -25dBm per carrier
4
PLL maximum comparison frequency
-152
PLL phase noise at phase detector
Note: ` 6dB interstage filter loss assumed in external base band paths.
` dBm assumes 75Ω characteristic impedance.
Functional Description
General
The SL1935 is a complete wideband direct conversion
tuner incorporating an on board frequency synthesiser
and LNA/AGC, optimised for application in digital satellite
receiver systems. The device offers a highly integrated
solution to a satellite tuner function, incorporating an I2C
bus interface controller, a low phase noise PLL frequency
synthesiser and all tuner analogue functionality. The
analogue blocks include the reference oscillator,
consisting of two independent oscillators, a phase splitter,
RF preamplifier with AGC facility, channel mixers and
baseband amplifiers incorporating two selectable
baseband paths, allowing for two externally definable
bandwidths. In this application two varactor tuned tanks,
a reference crystal and baseband filtering components
are required to complete the tuner system.
A buffered crystal frequency output is available to clock
the QPSK demodulator and powers up in the active
state.
The I2C bus interface controls the frequency synthesiser,
the local oscillator, the baseband path selection, the
buffered reference frequency output and an external
switching port.
Figure 2 shows the device block diagram and pin
allocations are shown in Figure 1.
Units
MHz
dBm
dB
dB
dB
dBm
dBm
dBm
V
dB
deg
dB
dBc/Hz
dBm
dBc
dBc
MHz
dBc/Hz
Quadrature Downconverter Section
In normal application the tuner IF frequency of typically
950 to 2150MHz is fed direct to the SL1935 RF input
through an appropriate impedance match (Fig.16) and
LNB switching. The input stage is optimised for both NF
and signal handling.
The signal handling of the front end is designed to offer
immunity to input composite overload without the
requirement of a tracking filter. RF input impedance is
shown in Fig.3.
The RF input amplifier feeds an AGC stage and provides
system gain control. The system AGC gain range will
guarantee an operating dynamic range of -70 to -20dBm.
The AGC is controlled by the AGC sender and is optimised
for S/N and S/I performance across the full dynamic
range. Details of the AGC characteristics, variations in
IIP3, IIP2, P1dB and NF are illustrated in Figs.4, 5, 6, 7,
and 8 respectively.
The required I and Q local oscillator frequencies for
quadrature downconversion are generated by the onboard reference oscillators designated ‘VCOS’ and
‘VCOV’. VCOS operates nominally from 1900 to 3000MHz
and is then divided by two to provide 950 to 1500MHz.
VCOV operates nominally from 1400 to 2200MHz. Only
the oscillator selected via bit VS in the I2C data
transmission is powered.
3
SL1935
Quadrature Downconverter Section - continued
The oscillators share a common varactor line drive and
both require an external varactor tuned resonator
optimised for low phase noise performance. The
recommended application circuit for the local oscillators
is detailed in Fig.9 and the typical phase noise
performance is detailed in Fig.10. The local oscillator
frequency is coupled internally to the PLL frequency
synthesiser programmable divider input.
The mixer outputs are coupled to the baseband buffer
amplifiers, providing for one of two selectable baseband
outputs in each channel. The required output is selected
by bit BS in the I2C bus transmission (Table 6). These
outputs are fed off chip via ports ‘OPIA’ and ‘OPIB’
(‘OPQA’ and ‘OPQB’), then back on chip through ports
‘IPIA’ and ‘IPIB’ (‘IPQA’ and ‘IPQB’), allowing for the
insertion of two independent user definable filter
bandwidths. Each output provides a low impedance
drive (Fig.11) and each input provides a high impedance
load . An example filter for 30MS/s is detailed in Fig.13.
Both path gains are nominally equal. NB 6dB insertion
loss is assumed in each channel, however a different pot
down ratio may be applied.
Each baseband path is then multiplexed to the final
baseband amplifier stage, providing further gain and a
low impedance output drive. The nominal output load
test condition is detailed in Fig.14.
PLL Frequency Synthesiser Section
The PLL frequency synthesiser section contains all the
elements necessary, with the exception of a reference
frequency source and a loop filter to control the selected
oscillator to produce a complete PLL frequency
synthesised source. The device, produced using high
speed logic, allows for operation with a high comparison
frequency and enables the generation of a loop with
excellent phase noise performance.
The LO signal from the selected oscillator drives from the
phase splitter into an internal preamplifier, providing gain
and reverse isolation from the divider signals. The output
of the preamplifier interfaces directly with the 15-bit fully
programmable divider. The programmable divider has
MN+A architecture, the dual modulus prescaler is 16/17,
the A counter is 4-bits and the M counter is 11-bits.
The output of the programmable divider is fed to the
phase comparator and compared in both phase and
frequency domains to the comparison frequency. This
frequency is derived from either the on board crystal
controlled oscillator or from an external reference source.
In both cases the reference frequency is divided down to
the comparison frequency by the reference divider,
programmable into 1 of 29 ratios and detailed in Table 3.
The typical application for the crystal oscillator is shown
in Fig.15.
4
The output of the phase detector feeds a charge pump
and a loop amplifier. When used with an external loop
filter and a high voltage transistor it integrates the current
pulses into the varactor line voltage used to control the
selected oscillator.
The programmable divider output Fpd divided by two
and the reference divider output Fcomp are switched to
port P0 by programming the device into test mode. Test
modes are detailed in Table 4.
The crystal reference frequency can be switched to the
BUFREF output by bit RE as detailed in Table 7.
Programming
The SL1935 is controlled by an I2C data bus and is
compatible with both standard and fast mode formats.
Data and Clock are fed on the SDA and SCL lines
respectively as defined by the I2C bus format. The
device can either accept data (write mode) or send data
(read mode). The LSB of the address byte (R/W) sets the
device into write mode if it is low and read mode if it is
high. Tables 9a and 9b detail the format of the data. The
SL1935 may be programmed to respond to several
addresses and enables the use of more than one device
in an I2C bus system. Table 9c details the how the
address is selected by applying a voltage to the ‘ADD’
input. When the device receives a valid address byte, it
pulls the SDA line low during the acknowledge period
and during following acknowledge periods after further
data bytes are received. When the device is
programmed into read mode, the controller accepting
the data must pull the SDA line low during all status byte
acknowledge periods to read another status byte. If the
controller fails to pull the SDA line low during this period,
the device generates an internal ‘STOP’ condition which
inhibits further reading.
Write mode
Bytes 2 and 3 contain frequency information bits 214to 20
inclusive (Table 9). Byte 4 controls the synthesiser
reference divider ratio (Table 3) and the charge pump
setting (Table 5). Byte 5 controls test modes (Table 4),
baseband filter path select BS (Table 6), local oscillator
select VS (Table 8), buffered crystal reference output
select RE (Table 7) and the output port P0.
After reception and acknowledgment of a correct
address (byte 1), the first bit of the following byte
determines whether the byte is interpreted as byte 2 or
4, a logic ‘0’ indicates byte 2 and a logic ‘1’ indicates byte
4. Having interpreted this byte as either byte 2 or 4, the
following byte will be interpreted as byte 3 or 5
respectively. After receiving two complete data bytes,
additional data bytes may be entered and byte
interpretation follows the same procedure without readdressing the device. The procedure continues until a
‘STOP’ condition is received.
SL1935
The STOP condition can be generated after any data
byte, if however it occurs during a byte transmission, the
previous byte data is retained. To facilitate smooth fine
tuning, the frequency data bytes are only accepted by
the device after all 15 bits of frequency data have been
received, or after the generation of a STOP condition.
Read mode
When the device is in read mode, the status byte read
from the device takes the form shown in Table 9b.
Bit 1 (POR) is the power-on reset indicator, and this is set
to a logic ‘1’ if the Vccd supply to the device has dropped
below 3V (at 25oC),e.g. when the device is initially turned
ON. The POR is reset to ‘0’ when the read sequence is
terminated by a STOP command. When POR is set high
this indicates that the programmed information may
have been corrupted and the device reset to the power
up condition.
Bit 2 (FL) indicates whether the synthesiser is phase
locked, a logic ‘1’ is present if the device is locked, and
a logic ‘0’ if the device is unlocked.
Table 2. Programmable Features
Programmable features
Function
Function as described above
Function as described above.
Function as described above.
Function as described above.
The charge pump current can be programmed by bits C1 & C0 (Table 5).
The test modes are defined by bits T2 - T0 as described in Table 4.
The general purpose port can be programmed by bit P0;
Logic ‘1’ = on
Logic ‘0’ = off (high impedance)
The buffered crystal reference frequency can be switched to the BUFREF
Buffered crystal reference output,
output by bit RE as described in Table 7. The BUFREF output defaults to
BUFREF
the ‘ON’ condition at device power up.
The typical key performance data at Vcc = 5V and +25oC ambient are detailed in Table 1.
Synthesiser programmable divider
Reference programmable divider
Baseband filter path select
Local oscillator select
Charge pump current
Test mode
General purpose port, P0
Table 3. Reference division ratios
R4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
R3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
R2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
R1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
R0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Ratio
2
4
8
16
32
64
128
256
Illegal state
5
10
20
40
80
160
320
Illegal state
6
12
24
48
96
192
384
Illegal state
7
14
28
56
112
224
448
5
SL1935
Table 4. Test modes
T2
0
0
0
0
1
1
1
1
T1
0
0
1
1
0
0
1
1
Test mode description
Normal operation
Charge pump sink* (status byte FL set to logic '0')
Charge pump source* (status byte FL set to logic '0')
Charge pump disabled* (status byte FL set to logic '1')
Normal operation and port P0 = Fpd/2
Charge pump sink* (status byte FL set to logic '0'. Port P0 = Fcomp)
Charge pump source* (status byte FL set to logic '0'. Port P0 = Fcomp)
Charge pump disabled* (status byte FL set to logic '1'. Port P0 = Fcomp)
T0
0
1
0
1
0
1
0
1
Note: * Clocks need to be present on crystal and RF inputs to enable charge pump test modes and to
toggle status byte bit FL.
Table 5. Charge pump current
C1
C0
0
0
1
1
0
1
0
1
Current in µA
min
typ
max
+-116
+-155
+-194
+-247
+-330
+-412
+-517
+-690
+-862
+-1087 +-1450 +-1812
Table 6. Baseband path select
BS
0
1
Path Selected
I Channel
Q Channel
Filter drive Baseband Filter drive Baseband
output amp input output amp input
IFQB
IFIB
OFQB
OFIB
IFQA
IFIA
OFQA
OFIA
Table 7. Buffered crystal
reference output select
RE
0
1
BUFREF output
Disabled, high impedance
Enabled
Table 8. Local oscillator select
VS
0
1
6
Local oscillator selected
VCOV
VCOS
SL1935
Table 9a. Write data format (MSB is transmitted first)
Address
Programmable
divider
Programmable
divider
Control data
Control data
MSB
1
0
1
214
0
213
0
212
0
211
MA1
210
MA0
29
LSB
0
28
A
A
Byte 1
Byte 2
27
26
25
24
23
22
21
20
A
Byte 3
1
T2
C1
T1
C0
T0
R4
VS
R3
BS
R2
0
R1
RE
R0
P0
A
A
Byte 4
Byte 5
MA1
0
MA0
0
LSB
1
0
A
A
Table 9b. Read data format (MSB is transmitted first)
MSB
1
POR
Address
Status Byte
1
FL
0
0
0
0
0
0
Byte 1
Byte 2
Table 9c. Address selection
MA1
0
0
1
1
Address input voltage level
0 - 0.1 Vcc
Open circuit
0.4 Vcc - 0.6 Vcc*
0.9 Vcc - Vcc
MA0
0
1
0
1
Note: * Programmed by connecting a 30kΩ resistor between pin and Vcc
Key to Tables 9a to 9c
A ......................................... Acknowledge bit
MA1, MA0 ........................... Variable address bits (Table 9c)
214 to 20................................ Programmable division ratio control bits
C1 to C0 .............................. Charge pump current select (Table 5)
R4 to R0 .............................. Reference division ratio select (Table 3)
T2 to T0 .............................. Test modes control bits (Table 4)
BS ....................................... Baseband path select (Table 6)
VS ....................................... Local oscillator select (Table 8)
RE ....................................... Buffered crystal reference output enable (Table 7)
P0 ....................................... P0 port output state
POR .................................... Power on reset indicator
FL ........................................ Phase lock flag
+j1
+j2
+j0.5
+j0.2
0
+j5
0.2
0.5
2
1
Marker Freq (MHz)
950
1
1400
2
1600
3
4
2150
5
X
Z real Ω Z imag Ω
-100
64
-75
40
-65
32
23
-45
—j5
—j0.2
X
4
X
X
3
Normalised to 75Ω
1
—j2
—j0.5
START 950MHz
X
2
—j1
STOP 2150MHz
Figure 3. RF input impedance (typical)
7
SL1935
90
System gain (dB) assuming
6dB interstage filter loss
80
70
70dB minimum, AGC < 0.75V
60
50
40
30
20
20dB maximum, AGC > 4.25V
10
0
0
0.5
1
1.5
2
2.5
3
AGCCONT Voltage (V)
3.5
4
4.5
5
Figure 4. AGC characteristic (typical)
System input referred IP3 (dBuV)
120
110
100
90
80
70
60
20
25
30
35
40
45
50
55
60
65
70
System gain (dB) assuming 6dB interstage filter loss
Figure 5. Variation in IIP3 with system gain (typical)
System input referred IP2 (dBuV)
170
160
Baseband dominated IP2
150
140
130
LNA dominated IP2
120
110
100
20
25
30
35
40
45
50
55
System gain (dB) assuming 6dB interstage filter loss
Figure 6. Variation in IIP2 with system gain (typical)
8
60
65
70
SL1935
Converter input referred P1dB (dBuV)
110
105
100
95
90
85
80
75
70
65
60
-10
25
10
0
5
30
35
15
20
Converter gain seting (dB) from RF inputs OFIA/OFQA or OFIB/OFQB outputs
-5
40
45
Figure 7. Variation in P1dB with converter gain (typical)
60
Noise figure (dB)
50
40
30
20
10
0
20
25
30
35
40
45
50
55
60
System gain (dB) assuming 6dB interstage filter loss
65
70
75
80
Figure 8. Variation in NF with system gain (typical)
BB837
4mm STRIPLINE 6
Tanks
1kΩ
"vcos"
2kΩ
BB837
4mm STRIPLINE
7
Tanksb
Vcnt
BB831
10mm STRIPLINE
9
Tankv
"vcov"
2kΩ
1kΩ
BB831
10mm STRIPLINE
10
Tankvb
NOTE:
Stripline width = 0.44mm
(dimensions are approximate)
Figure 9. Local oscillator application circuit
9
SL1935
LO Frequency (MHz)
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
-70
Phase noise @ 10kHz offset (dBc/Hz)
-72
vcos enabled
-74
vcov enabled
-76
-78
-80
-82
-84
-86
Conditions:
Loop filter as per standard application shown in Figure 21
Charge pump = 130uA
Fcomp = 65.5kHz or 125kHz
-88
-90
Figure 10. Local oscillator phase noise variation with frequency (typical)
+j1
+j0.5
+j2
3
+j0.2
0
4
x
x
+j5
2x
1 0.5
0.2
x
2
1
Marker
1
2
3
4
5
Freq (MHz)
1
10
20
30
Z real Ω
17
18
22
33
Z imag Ω
0
19
38
60
—j5
—j0.2
—j2
—j0.5
START 1MHz
Normalised to 50Ω
STOP 30MHz
—j1
Figure 11. Converter output impedance; OFIA, OFIB, OFQA, OFQB (typical)
+j1
+j0.5
+j2
+j0.2
+j5
Marker
1
2
3
4
X4
0
0.2 X3
X2
X1
0.5
1
2
5
X
Z real Ω
9.5
10.0
10.6
12.6
—j5
—j0.2
—j2
—j0.5
START 100kHz
Normalised to 50Ω
Freq (MHz)
0.1
10
20
30
—j1
STOP 30MHz
Figure 12. Baseband output impedance; IOUT, QOUT (typical)
10
Z imag Ω
-2.0
1.3
3.3
5.5
SL1935
100nF
OFIA/OFIB
OFQA/OFQB
100nF
1k Ω
IFIA/IFIB
IFQA/IFQB
1k Ω
3.9pF
Figure 13. Example baseband interstage filter for 30MS/s
220nF
100 Ω
1k Ω
15pF
Figure 14. Nominal baseband output load test condition
1 XTALCAP
150pF
2 XTAL
82pF
4MHz
Figure 15. Crystal oscillator application (typical)
11
SL1935
1pF
100pF
8
RFIN
9
2.2pF
RF
RFB
SL1935
33 Ω
100pF
Figure 16. Input matching network
Table 10. Electrical Characteristics
Test conditions (unless otherwise stated); Tamb = -20o to +80oC, Vee= 0V, Vcc =Vccd = 5V+-5%.
These characteristics are guaranteed by either production test or design. They apply within the specified ambient
temperature and supply voltage unless otherwise stated.
Characteristic
Value
Pin
Min
Supply current
RF input operating frequency
SYSTEM
6,7,10
13,24
8,9
130
175
mA
2150
MHz
10
15
Variation in system NF with gain
adjust
System input referred IP2
121
Variation in system input referred
IP2 with operating sensitivity
System input referred IP3
112
Variation in system input referred
IP3 with operating sensitivity
Max
950
System noise figure DSB
Units
Typ
140
12
17
-1
Conditions
VCCD (PLL) and VCC
All system specification items should
be read in conjunction with Note 2
dB At -70dBm operating sensitivity
dB At -60dBm operating sensitivity
dB/dB Above –60dBm operating sensitivity,
(Fig.7)
dBµV At –20dBm operating sensitivity, see
Notes 3 and 4
(Fig.6)
dBµV At -20dBm operating sensitivity,
see Note 5
(Fig.5)
Continued
12
SL1935
Table 10. Electrical Characteristics (Continued)
Characteristic
Value
Pin
Min
Typ
Units
dBm
dBm
dB
dB
Note 6
AGCCONT = 0.75V
AGCCONT = 4.25V
Within RF band 950-2150MHz
-20˚C to +80˚C
Interstage filter (Fig.13)
Interstage filter (Fig.13)
Interstage filter (Fig.13)
System dynamic range
-70
-20
System gain roll off
System gain variation with
temperature
System I Q gain match
System I Q phase balance
System I and Q channel in band
ripple
System baseband path gain
match
LO second harmonic interference
level
LNA second harmonic
interference level
Synthesiser and other spurii on I
and Q outputs
3
2
17,20
17,20
17,20
8,9
CONVERTER
Converter input impedance
Converter input return loss
System input referred P1dB
8,9
8,9
Converter output impedance, OFIA, 14,15
OFIB, OPQA and OPQB.
22,23
Conver ter output leakage to
unselected output, OFIA, OFIB,
OPQA and OPQB.
Oscillator VCOS operating range 31,32
Oscillator VCOV operating range
Local oscillator SSB phase noise
AGCONT input current
-1
-3
+1
+3
1
dB
deg
dB
-1
+1
dB
-50
dBc
Note 8.
-35
dBc
Note 9.
76
17,20
In band leakage to RF input
28,29
-60
75
8
102
25
50
1900
3000
1450
-150
dBµV Within 0-100MHz band under all gain
settings, RF input set to deliver
108dBµV on output
dBm Within RF band 950-2150MHz.
Note 11.
Ω
dB
With input matching (Fig.16)
dBµV Converter gain =-5dBm (to OFIA/
OPQA, OFIB/OPQB outputs. Fig.7)
Ω
0.1 to 30MHz (Fig.11)
dBc
-26
-78
19
Giving LO = 950 to 1500MHz
(Application as in Fig.9)
2150 MHz (Application as in Fig.9)
dBc/Hz @10kHz offset, PLL loop bw < 1kHz
Application is measured at baseband
output frequency of 10MHz (Fig.10).
150
µA
The baseband inputs must be
externally ac coupled
0.1- 30MHz bandwidth
11,12
25,26
17,20
5
-40
kΩ
pF
dBc
17,20
20
Ω
10
17,20
17,20
Relative to selected output
MHz
BASEBAND AMPLIFIERS
Baseband input impedance, IFIA,
IFIB, IFQA And IFQB.
Resistance
Capacitance
Baseband unselected input
leakage to output
Baseband amplifier output
impedance
Baseband output limiting
Baseband bandwidth 1dB
Baseband output roll-off
Conditions
Max
2.0
40
6
Relative to selected input.
Vp-p Level at hard clipping (load as Fig.14)
MHz (Load as Fig.14)
dB/oct Above 3dB point, no load
Continued
13
SL1935
Table 10. Electrical Characteristics (Continued)
Characteristic
Value
Pin
Min
SYNTHESISER
SDA,SCL
Input high voltage
Input low voltage
Input high current
Input low current
Leakage current
Hysterysis
SDA output voltage
SCL clock rate
Charge pump output current
Charge pump output leakage
Charge pump drive output current
Crystal frequency
Recommended crystal series
resistance
External reference input frequency
External reference drive level
Phase detector comparison
frequency
Equivalent phase noise at phase
detector
Local oscillator programmable
divider division ratio
Reference division ratio
Output port P0
Sink current
Leakage current
BUFREF output
Output amplitude
Output impedance
Address select
Input high curent
Input low current
Typ
Units
I2C 'fast mode' compliant
3,4
3
0
5.5
1.5
10
V
V
µA
µA
10
µA
V
V
V
kHz
-10
0.4
0.4
0.6
400
3
4
36
36
35
1,2
Conditions
Max
+-3
+-10
0.5
2
10
20
200
2
2
20
2
0.2
0.5
4
nA
mA
MHz
Ω
Vcc = Vee = 0V
Isink = 3mA
Isink = 6mA
Vpin36 = 2V. (Table 5)
Vpin36 = 2V
Vpin35 = 0.7V
(Fig.15 for application)
4MHz parallel resonant crystal
MHz Sinewave coupled via 10nF blocking
capacitor
Vpp Sinewave coupled via 10nF blocking
capacitor
MHz
dBc/Hz SSB within loop bandwidth, all
comparison frequencies
-152
32767
240
34
2
10
mA
µA
5
0.25
Input voltage = Vcc
Input voltage = Vee
0.35
250
0.45
Vpp
Ω
1
-0.5
mA
mA
18
(Table 3)
(Note 7)
Vport = 0.7
Vport = Vcc
AC coupled. (Note 10.)
Enabled by bit RE = 1 and default
state on power-up.
(Table 9c)
Vin = Vcc
Vin = Vee
Notes to Table 10
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
14
All power levels are referred to 75Ω, and 0dBm = 109dBµV.
System specifications refer to total cascaded system of converter/AGC stage and baseband amplifier stagewith nominal
6dB pad as interstage filter and load impedance as detailed in Figure 14.
Baseband dominated IP2. AGC set for 20dB system gain with two tones for intermodulation test at fc+146and
fc+155MHz at 100dBµV generating output intermodulation spur at 9MHz. 30MHz 3dB bandwidthinterstage filter included.
LNA dominated IP2. AGC set for 20dB system gain with two tones for intermodulation test at fc+146 and2*fc+155 MHz at
100dBµV generating output intermodulation spur at 9MHz. 30MHz 3dB bandwidthinterstage filter included.
AGC set for 20dB system gain with two tones for intermodulation test at fc+110 and fc+211MHz at 100dBµVgenerating
output intermodulation spur at 9MHz. 30MHz 3dB bandwidth interstage filter included.
Dynamic range assuming termination as detailed in Figure 14, and including 6 dB interstage filter insertion loss,
delivering 700mVp-p at baseband outputs (pins 17,20). AGC monotonic from Vee to Vcc (Fig.4).
Port powers up in high impedance state.
The level of 2.01GHz downconverted to baseband relative to 1.01GHz with the oscillator tuned to 1GHz,measured with
no input pre-filtering.
The level of second harmonic of 1.01GHz input at –25dBm downconverted to baseband relative to 2.01GHz at–40 dBm
with the oscillator tuned to 2GHz, measured with no input pre-filtering.
If the BUFREF output is not used it should be left open circuit or connected to Vccd, and disabled by settingRE = ‘0’.
This parameter is very application dependant. With good RF isolation <-60dBm can be achieved.
SL1935
VCC
VREF
RF
8
5K
RFB
9
AGCCONT
RF inputs
19
30K
AGC input
VREF2
1K
1K
TANK
OFIA
OFIB
OFQA
OFQB
TANKB
Oscillator inputs (pins 28, 29 and 31, 32)
IFIA
IFIB
IFQA
IFQB
BIAS
Baseband amplifier inputs
(pins 11, 12, 25 and 23)
Converter outputs (pins 14, 15, 22 and 23)
IOUT
and
QOUT
Baseband outputs (pins 17 and 20)
Figure 17. Input and output interface circuits (RF section)
15
SL1935
Vccd
Vccd
36 PUMP
XTAL
XTALCAP
2
1
300
35 DRIVE
Loop amplifier
Reference oscillator
Vccd
Vccd
60K
3K
47K
ADD
SCL/SDA
ACK
]
18
20K
] On SDA only
ADD input
SDA/SCL (pins 3 and 4)
Vccd
P0
34
5
BUFREF
ENABLE/
DISABLE
Output port
BUFREF output
Figure 18. Input and output interface circuits (PLL section)
16
SL1935
Table 11. Absolute Maximum Ratings (All voltages referred to Vee at 0V and Vcc = Vccd)
Characteristic
Supply voltage
SDA, SCL DC offsets
All I/O port DC offsets
Por t P0 current
Storage temperature
Junction temperature
Package thermal resistance,
chip to case
Package thermal resistance,
chip to ambient
Power consumption at 5.25V
ESD protection
Min
Max
Units
-0.3
-0.3
-0.3
7
6
Vcc+0.3
10
150
150
20
V
V
V
mA
oC
oC
oC/W
77
oC/W
919
mW
kV
-55
3.5
Conditions
Vcc = Vee to 5.25V
Mil-std 883 method 3015 cat1
SL1935 Demo Board
The demo board contains an SL1935 I2C bus controlled
Zero IF tuner IC, plus all components necessary to
demonstrate operation of the SL1935. The schematic
and PCB layout of the board are shown in Figures 19, 20
and 21.
Supplies
The board must be provided with the following supplies:
5V for the synthesiser section (5VD)
5V for the converter and baseband sections (5V)
30V for the varactor line (30V)
The supply connector is a 5 pin 0.1” pin header.
The order of connections is 5V – GND – 30V – GND – 5V.
I2C bus connections
The board is provided with a RJ11 I2C bus connector
which feeds directly to the synthesiser. This connects to
a standard 4 way cable.
Operating instructions
1. Software.
Use the Zarlink Semiconductor synthesiser software. Pull
down the ‘Device’ menu, then select the ‘SL1935’. It is
suggested that the charge pump is set to 130uA with a
reference divider ratio of 32. These settings give a small
loop bandwidth (i.e. 100’s Hz), which allows detailed
phase noise measurements of the oscillators to be taken
if desired.
2. VCO control.
The two VCO’s are selected by toggling the oscillator
switch below the two oscillators on the main software
block diagram. This switch programs bit VS of the I2C data
(see Tables 8 and 9a to 9c).
VCOS oscillates at twice the LO frequency (lower band)
and is then divided by two to provide the required LO
frequency in the range 950MHz to 1500MHz
(approximately).
VCOV oscillates at the LO frequency (upper band) in the
range 1500MHz to 2150MHz (approximately).
3. Baseband path select.
The SL1935 has two filter paths selected by programming
bit BS of the I2C data (see Tables 6 and 9a to 9c). The
value of BS is changed by toggling the switch position to
the left of ‘Filter A’ and ‘Filter B’ on the main software block
diagram.
4. AGC control.
The conversion gain of the SL1935 is set by the voltage
applied to the AGCCONT input. On the demo board this
is controlled by the potential divider labelled ‘AGC ADJ’
which varies the AGCCONT input from 0V to Vcc.
CAUTION: Care should be taken to ensure the chip is
powered ON if the board is modified to accept an external
AGC input voltage. Damage to the device may result if this
is not complied with as a result of the IC powering itself up
via the AGCCONT input ESD protection diode. It is
recommended that a low current limit is set on any
external AGC voltage source used.
5. Free running the VCO’s.
Select the required VCO as detailed in (2) above. Program
an LO frequency which is above the maximum capability
of the oscillator. 3GHz is suggested. Under this condition
the varactor control voltage is pumped to its maximum
value, ie to the top of the band. The oscillator frequency
can now be manually tuned by varying the 30V supply.
17
SL1935
19.
View
Figure 19. Top view
18
SL1935
Figure 20.
Bottom view
19
CN8
C26
68pF
C27
15nF
TP6
5
4
3
2
1
R18
13K
R19
13K
C2
82pF
I2C
C3
150pF
5VD
1
2
TP1
SK1
RF IN
SDA
5V0
GND
SCL
RFinA
3
3
4
5
6
4
TP2
TP3
5VD
C40
100pF 5V
C39
100pF
RFinA
1nF
5V
1nF
R7
C6
C7
C8
IOUT
R1 1K
R2
QOUT
C11
3p9
R3
1K
R4
1K
8
9
75R
SK3
6
7
C5
SK2
I OUT
5
10
100nF 11
100nF 12
5V
13
C9
100nF 14
C10
100nF 15
1K
SDA
PORT P0
SCL
Vee
TANKSa
BUFref
TANKSb
VccD
Vee
Vcc
RFin
TANKVa
RFinB
TANKVb
Vee
Vcc
IFQA
IFIa
Q OUT
of
IFIb
IFQB
Vcc
Vcc
OFIb
17
18
C13
220nF
DRIVE
XTAL
16
C12
3p9
PUMP
XTALCAP
OFIa
OFQA
OFQB
Vee
Vee
Iout
Qout
ADD
C28
100nF
AGC cont
+ C30
22uF
30V
36
TR1
BCW31
TP5
35
R17
1K
R16
1K
C31
100nF
34 P0
C32
100pF
D1 BB837
5V
33
L1
32
R23
2K
L2
31
D3
30
D4
5VD
BB831
100nF
25 C23
5V
24
100nF
23 C22
100nF
22 C21
100nF
R21
620R
R15
2K7
TP8
AGC
R14 1K
AGC
RV1
5K
D5
PORT 0
R13 1K
21
R22
620R
OFQB
20
C19
3p9
C18
220nF
19
SL1935
C36
100nF
C35
100pF
5V
GND
26 C24
C34
100pF
R24
2K
L4
28
C33
100pF
D2 BB837
L3
29
27
BB831
R11
1K
R12
1K
C20
3p9
1
2
AGC
TP4
R5
100R
C16
10nF
QOUT
IOUT
C14
C29
100pF
C25
2n2
IC1
XL1
4MHz
CN7
5VD
DC POWER
R20
22K
R6
1K
TP7
R10
100R
R9 1K
C17 15pF
15pF
Figure 21.
P0
JP1
C37
100pF
C38
+ 22uF
SL1935
20
30V
SL1935
Purchase of Zarlink Semiconductor I2C components conveys a licence under the Phillips I2C Patent rights to use
these components in an I2C system,provided that the system conforms to the I 2C Standard Specification as
defined by Phillips.
21
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visit our Web Site at
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However, Zarlink assumes no liability for errors that may appear in this publication, or for liability otherwise arising from the application or use of any such
information, product or service or for any infringement of patents or other intellectual property rights owned by third parties which may result from such application or
use. Neither the supply of such information or purchase of product or service conveys any license, either express or implied, under patents or other intellectual
property rights owned by Zarlink or licensed from third parties by Zarlink, whatsoever. Purchasers of products are also hereby notified that the use of product in
certain ways or in combination with Zarlink, or non-Zarlink furnished goods or services may infringe patents or other intellectual property rights owned by Zarlink.
This publication is issued to provide information only and (unless agreed by Zarlink in writing) may not be used, applied or reproduced for any purpose nor form part
of any order or contract nor to be regarded as a representation relating to the products or services concerned. The products, their specifications, services and other
information appearing in this publication are subject to change by Zarlink without notice. No warranty or guarantee express or implied is made regarding the
capability, performance or suitability of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute
any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user’s responsibility to fully determine the performance and
suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. Manufacturing does
not necessarily include testing of all functions or parameters. These products are not suitable for use in any medical products whose failure to perform may result in
significant injury or death to the user. All products and materials are sold and services provided subject to Zarlink’s conditions of sale which are available on request.
Purchase of Zarlink’s I2C components conveys a licence under the Philips I2C Patent rights to use these components in and I2C System, provided that the system
conforms to the I2C Standard Specification as defined by Philips.
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