EVALUATION KIT AVAILABLE
MAX2121B
L-Band Tuner with Programmable
Baseband Filter
General Description
The MAX2121B low-cost, direct-conversion tuner IC is
designed for satellite set-top and VSAT applications.
The device directly converts the satellite signals from the
LNB to baseband using a broadband I/Q downconverter.
The operating frequency range extends from 925MHz to
2250MHz.
The device includes an LNA and an RF variable-gain ampli-
fier, I and Q downconverting mixers, and digitally controlled
baseband filters (40MHz to 124MHz) and variable-gain
amplifiers. Together, the RF and baseband variable-gain
amplifiers provide more than 80dB of gain control range.
The device includes fully monolithic VCOs, as well as a
complete fractional-N frequency synthesizer. Additionally,
an on-chip crystal oscillator is provided along with a buff-
ered output for driving additional tuners and demodula-
tors. Synthesizer programming and device configuration
are accomplished with a 2-wire serial interface. The IC
features a VCO autoselect (VAS) function that automati-
cally selects the proper VCO. For multituner applications,
the device can be configured to have one of two 2-wire
interface addresses. A low-power standby mode is avail-
able whereupon the signal path is shut down while leaving
the reference oscillator, digital interface, and buffer cir-
cuits active, providing a method to reduce power in single
and multituner applications.
The device is the most advanced broadband/VSAT DBS
tuner available. The low noise figure eliminates the need
for an external LNA. A small number of passive compo-
nents are needed to form a complete broadband satellite
tuner DVB-S2 RF front-end solution. The tuner is avail-
able in a very small, 5mm x 5mm, 28-pin TQFN package.
●
Monolithic Receiver Saves Cost and Space
•
Integrated VCO with Low Phase Noise: -97dBc/Hz
at 10kHz
•
Integrated 14-Bit Fractional-N Synthesizer
•
Address Pin Allows for Multi-Tuner Applications
●
Low Power Reduces Cost
•
495mW Power Dissipation
•
10mW Standby Mode
●
High Dynamic Range Eliminates Need for External
LNA and/or Attenuators
•
-75dBm to 0dBm Input Power
•
8dB Noise Figure
●
Integrated LP Filters Simplify Design
•
Programmable Bandwidth from 40MHz to 124MHz
●
Differential I/Q Interface Minimizes EMI
•
1V
P-P
Full-Scale Outputs
●
Serial Interface and Small Package Reduce Size
•
5mm x 5mm, 28-Pin TQFN Package
•
I
2
C 2-Wire Serial Interface
Benefits and Features
Functional Diagram
V
CC_BB
ADDR
QDC+
23
QDC-
SCL
28
27
SDA
26
25
24
IDC-
22
21
IDC+
IOUT-
IOUT+
QOUT-
QOUT+
20
19
18
17
DIV2/DIV4
EP
FREQUENCY
SYNTHESIZER
16
15
8
BYPVCO
9
TUNEVCO
10
GNDTUNE
11
GNDSYN
12
CPOUT
13
V
CC_SYN
14
XTAL
+
V
CC_RF2
V
CC_RF1
GND
RFIN
GC1
1
2
3
4
5
INTERFACE LOGIC
AND CONTROL
MAX2121B
DC OFFSET
CORRECTION
Applications
●
●
●
●
VSATs
Navigation Systems
Satellite Set-Top Box
DBS Tuner
V
CC_LO
V
CC_VCO
6
7
V
CC_DIG
REFOUT
Ordering Information
appears at end of data sheet.
19-7601; Rev 1; 9/16
MAX2121B
L-Band Tuner with Programmable
Baseband Filter
Absolute Maximum Ratings
VCC_ to GND.........................................................-0.3V to +3.9V
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
RF Input Power: RFIN.....................................................+10dBm
BYPVCO, CPOUT, XTAL, REFOUT, IOUT_, QOUT_, IDC_,
QDC_ to GND Short-Circuit Protection...............................10s
Continuous Power Dissipation (TA = +70°C)
TQFN (derate 34.5mW/°C above +70°C)......................2.75W
Operating Temperature Range..............................-40°C to +85°C
Junction Temperature.......................................................+150°C
Storage Temperature Range...............................-65°C to +160°C
Lead Temperature (soldering, 10s)...................................+300°C
Soldering Temperature (reflow)........................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
CAUTION!
ESD SENSITIVE DEVICE
DC Electrical Characteristics
(MAX2121 Evaluation Kit: V
CC_
= +3.13V to +3.47V, f
XTAL
= 27MHz, T
A
= -40°C to +85°C, V
GC1
= +0.5V (max gain), default register
settings except BBG[3:0] = 1011, LPF[7:0] =97h. No input signals at RF, baseband I/Os are open circuited. Typical values measured
at V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SUPPLY
Supply Voltage (V
CC_
)
Supply Current
Receive mode, bit STBY = 0
Standby mode, bit STBY = 1
2.4
0.5
50
-50
Maximum gain = 0.5V
0.5
-50
0.4
2.7
+50
2.3
400
0.7 x
V
CC
0.3 x
V
CC
Digital inputs = GND or V
CC
I
SINK
= 1mA (Note 2)
±0.1
±1
0.4
3.13
3.3
148
3
3.47
200
V
mA
CONDITIONS
MIN
TYP
MAX
UNITS
ADDRESS SELECT INPUT (ADDR)
Digital Input-Voltage High, V
IH
Digital Input-Voltage Low, V
IL
Digital Input-Current High, I
IH
Digital Input-Current Low, I
IL
ANALOG GAIN-CONTROL INPUT (GC1)
Input Voltage Range
Input Bias Current
VCO TUNING VOLTAGE INPUT (TUNEVCO)
Input Voltage Range
2-WIRE SERIAL INPUTS (SCL, SDA)
Clock Frequency
Input Logic-Level High
Input Logic-Level Low
Input Leakage Current
2-WIRE SERIAL OUTPUT (SDA)
Output Logic-Level Low
V
kHz
V
V
µA
V
V
µA
V
V
µA
µA
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Maxim Integrated
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2
MAX2121B
L-Band Tuner with Programmable
Baseband Filter
AC Electrical Characteristics
(MAX2121 Evaluation Kit: V
CC_
= +3.13V to +3.47V, f
XTAL
= 27MHz, T
A
= -40°C to +85°C, default register settings except BBG[3:0] = 1111,
LPF[7:0] = 97h. Typical values measured at V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
MAIN SIGNAL PATH PERFORMANCE
Minimum Gain
Gain Flatness
Input Frequency Range
RF Gain-Control Range (GC1)
Baseband Gain-Control Range
In-Band Input IP3
Out-of-Band Input IP3
Input IP2
f
IN
= 2175MHz
925MHz to 2250MHz (Note 2)
(Note 3)
0.5V < V
GC1
< 2.7V
Bits BBG[3:0] = 1111 to 0000
(Note 4)
(Note 5)
(Note 6)
V
GC1
is set to 0.5V (maximum RF gain) and BBG[3:0] is
adjusted to give a 1V
P-P
baseband output level for a
-75dBm CW input tone at 1500MHz
Starting with the same BBG[3:0] setting as above, V
GC1
is adjusted to back off RF gain by 10dB (Note 2)
Minimum RF Input Return Loss
Nominal Output Voltage Swing
I/Q Amplitude Imbalance
I/Q Quadrature Phase Imbalance
Single-Ended I/Q Output
Impedance
Output 1dB Compression Voltage
Baseband Highpass -3dB
Frequency Corner
Typical Filter Bandwidth Range
(-3dB)
Rejection Ratio
Group Delay
3dB Bandwidth Tolerance
FREQUENCY SYNTHESIZER
RF-Divider Frequency Range
RF-Divider Range (N)
Reference-Divider Frequency Range
Reference-Divider Range (R)
Phase-Detector Comparison
Frequency
925
19
12
1
12
2175
251
30
1
30
MHz
MHz
MHz
925MHz < f
RF
< 2175MHz, in 75Ω system
R
LOAD
= 200Ω//5pF
Measured at 500kHz
Measured at 500kHz
Real Z
O
, from 1MHz to 140MHz
Differential
47nF capacitors at IDC_, QDC_
24
3
400
0.5
BASEBAND OUTPUT CHARACTERISTICS
1
±1
3.5
V
P-P
dB
Degrees
Ω
V
P-P
Hz
925
65
11.5
73
13.5
+2
+15
+40
8
dB
9
12
12
dB
72
78
4
6
2250
dB
dB
MHz
dB
dB
dBm
dBm
dBm
CONDITIONS
MIN
TYP
MAX
UNITS
Noise Figure
BASEBAND LOWPASS FILTERS (5th-Order Butterworth with 1st-Order Group Delay Compensation)
LPF[7:0] = 2Eh to 97h
At 247.5MHz, LPF[7:0] = 97h
Up to 0.5dB bandwidth
40
31
1.0
±10
124
MHz
dB
ns
%
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Maxim Integrated
│
3
MAX2121B
L-Band Tuner with Programmable
Baseband Filter
AC Electrical Characteristics (continued)
(MAX2121 Evaluation Kit: V
CC_
= +3.13V to +3.47V, f
XTAL
= 27MHz, T
A
= -40°C to +85°C, default register settings except BBG[3:0] = 1111,
LPF[7:0] = 97h. Typical values measured at V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Guaranteed LO Frequency Range
f
OFFSET
= 10kHz
LO Phase Noise
f
OFFSET
= 100kHz
f
OFFSET
= 1MHz
XTAL/REFERENCE OSCILLATOR INPUT AND OUTPUT BUFFER
XTAL Oscillator Frequency
Range f
XTAL
Input Overdrive Level
XTAL Output-Buffer Divider Range
XTAL Output Voltage Swing
XTAL Output Duty Cycle
12MHz to 30MHz, C
LOAD
= 10pF
Parallel-resonance-mode crystal (Note 7)
AC-coupled sine-wave input
12
0.5
1
1
1.5
50
1
30
2.0
8
2
MHz
V
P-P
—
V
P-P
%
CONDITIONS
MIN
925
-97
-100
-122
dBc/Hz
TYP
MAX
2250
UNITS
MHz
VOLTAGE-CONTROLLED OSCILLATOR AND LO GENERATION
Note 1:
Min/max values are production tested at T
A
= +25°C. Min/max limits at T
A
= -40°C and T
A
= +85°C are guaranteed by
design and characterization.
Note 2:
Guaranteed by design and characterization at T
A
= +25°C.
Note 3:
Input gain range specifications met over this band.
Note 4:
In-band IIP3 test conditions: GC1 set to provide the nominal baseband output drive when mixing down a -23dBm tone at
2175MHz to 5MHz baseband (f
LO
= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at
-26dBm each are applied at 2174MHz and 2175MHz. The IM3 tone at 3MHz is measured at baseband, but is referred to
the RF input.
Note 5:
Out-of-band IIP3 test conditions: GC1 set to provide nominal baseband output drive when mixing down a -23dBm tone at
2175MHz to 5MHz baseband (f
LO
= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at
-20dBm each are applied at 1919MHz and 1663MHz. The IM3 tone at 5MHz is measured at baseband, but is referred to
the RF input.
Note 6:
Input IP2 test conditions: GC1 set to provide nominal baseband output drive when mixing down a -23dBm tone at 2175MHz
to 5MHz baseband (f
LO
= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at -20dBm
each are applied at 925MHz and 1250MHz. The IM2 tone at 5MHz is measured at baseband, but is referred to the RF input.
Note 7:
See
Table 16
for crystal ESR requirements.
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Maxim Integrated
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4
MAX2121B
L-Band Tuner with Programmable
Baseband Filter
Typical Operating Characteristics
(MAX2121 Evaluation Kit: V
CC
= +3.3V, T
A
= +25°C, baseband output frequency = 5MHz, V
GC1
= +1.2V, default register settings except
BBG[3:0] = 1011, LPF[7:0] = 97h, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX2121 toc01
SUPPLY CURRENT (mA)
165
160
155
150
145
140
135
130
125
T
A
= -40°C
T
A
= +25°C
145
SUPPLY CURRENT (mA)
140
135
130
125
120
STANDBY SUPPLY CURRENT (mA)
170
T
A
= +85°C
2.5
T
A
= +85°C
2.0
T
A
= -40°C
1.5
3.1
3.2
3.3
3.4
3.5
46
62
78
94
110
126
142
158
1.0
SUPPLY VOLTAGE (V)
LPF[7:0] (DECIMAL)
3.1
3.2
3.3
3.4
3.5
SUPPLY VOLTAGE (V)
MAX2121 toc04
MAX2121 toc03
BASEBAND 3RD-ORDER HARMONIC (dBc)
QUADRATURE PHASE ERROR (DEG)
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
1.0
1.5
2.0
V
OUT
(V
P-P
)
2.5
f
BASEBAND
= 50MHz
QUADRATURE MAGNITUDE MATCHING (dB)
f
BASEBAND
= 50MHz
3.0
2.5
2.0
1.5
1.0
0.5
0
900
1150
T
A
= +25°C
T
A
= +85°C
T
A
= -40°C
0.8
0.6
0.4
0.2
0
T
A
= +85°C
T
A
= -40°C
T
A
= +25°C
3.0
1400
1650
1900
2150
900
1150
1400
1650
1900
2150
LO FREQUENCY (MHz)
LO FREQUENCY (MHz)
MAX2121 toc06
QUADRATURE MAGNITUDE MATCHING (dB)
QUADRATURE PHASE ERROR (DEG)
f
LO
= 1425MHz
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
f
LO
= 1425MHz
3.0
2.5
2.0
1.5
1.0
0.5
0
0.1
1
MAX2121 toc07
BASEBAND OUTPUT LEVEL (dB)
0.8
0.6
0.4
0.2
0
T
A
= +85°C
T
A
= -40°C
0.1
1
10
T
A
= +25°C
-5
-10
-15
-20
-25
-30
-35
LPF=151d
10
100
BASEBAND FREQUENCY (MHz)
100
-40
LPF=46d
0
50
LPF=84d
100
150
LPF=121d
200
250
300
BASEBAND FREQUENCY (MHz)
BASEBAND FREQUENCY (MHz)
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5
toc08
3.5
QUADRATURE PHASE ERROR
vs. BASEBAND FREQUENCY
1.0
QUADRATURE MAGNITUDE MATCHING
vs. BASEBAND FREQUENCY
0
BASEBAND FILTER FREQUENCY
RESPONSE
MAX2121 toc05
-10
HD3 vs. V
OUT
3.5
QUADRATURE PHASE ERROR
vs. LO FREQUENCY
1.0
QUADRATURE MAGNITUDE MATCHING
vs. LO FREQUENCY
MAX2121 toc02
175
150
SUPPLY CURRENT vs. LPF[7:0]
toc01a
3.0
STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
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