MAX2870
23.5MHz to 6000MHz Fractional/
Integer-N Synthesizer/VCO
Benefits and Features
General Description
The MAX2870 is an ultra-wideband phase-locked
loop (PLL) with integrated voltage control oscillators
(VCOs) capable of operating in both integer-N and
fractional-N modes. When combined with an external
reference oscillator and loop filter, the MAX2870 is
a high-performance frequency synthesizer capable
of synthesizing frequencies from 23.5MHz to 6.0GHz
while maintaining superior phase noise and spurious
performance.
The ultra-wide frequency range is achieved with the
help of multiple integrated VCOs covering 3000MHz to
6000MHz, and output dividers ranging from 1 to 128.
The device also provides dual differential output drivers,
which can be independently programmable to deliver
-4dBm to +5dBm output power. Both outputs can be
muted by either software or hardware control.
The MAX2870 is controlled by a 4-wire serial interface and
is compatible with 1.8V control logic. The device is available
in a lead-free, RoHS-compliant, 5mm x 5mm, 32-pin TQFN
package, and operates over an extended -40NC to +85NC
temperature range.
U
Integer and Fractional-N Modes
U
Manual or Automatic VCO Selection
U
3000MHz to 6000MHz Fundamental VCO
U
Output Binary Buffers/Dividers for Extended
Frequency Range
•
1/2/4/8/16/32 /64/128
•
23.5MHz to 6000MHz
U
High-Performance PFD
•
105MHz in Integer-N Mode
•
50MHz in Fractional-N Mode
U
Reference Frequency Up to 200MHz
U
Operates from +3.0V to +3.6V Supply
U
Dual Programmable Outputs
•
-4dBm to +5dBm
U
Analog and Digital Lock Detect Indicators
U
Hardware and Software Shutdown Control
U
Compatible with 1.8V Control Logic
Ordering Information
appears at end of data sheet.
Typical Application Circuit
appears at end of data sheet.
Applications
Wireless Infrastructure
Test and Measurement
Satellite Communications
Wireless LANs/CATV
PMAR /LMAR/Public
Safety Radio
Clock Generation
Functional Diagram
MUX
MUX_OUT
MAX2870
LOCK DETECT
REF_IN
CLK
DATA
LE
INTEGER
SPI AND
REGISTERS
VCO
FRAC
MODULUS
DIV-BY-
1/2/4/8/16
DIV-BY-
1/2/4/8
X2
MUX
R COUNTER
DIVIDE-BY-2
MUX
CHARGE
PUMP
LD
CP_OUT
CP_GND
TUNE
RFOUTA_P
RFOUTA_N
RFOUT_EN
MAIN
MODULATOR
MUX
N COUNTER
MUX
RFOUTB_P
RFOUTB_N
19-6250; Rev 6; 4/17
MAX2870
23.5MHz to 6000MHz Fractional/
Integer-N Synthesizer/VCO
Absolute Maximum Ratings
V
CC_
to GND_ .......................................................-0.3V to +3.9V
All Other Pins to GND_.............................. -0.3V to V
CC_
+ 0.3V
Continuous Power Dissipation (T
A
= +70NC)
TQFN-EP Multilayer Board
(derate 34.5mW/NC above +70NC) .........................2758.6mW
Junction Temperature .....................................................+150NC
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) .............................. +300NC
Soldering temperature (reflow) .......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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.
Package Thermal Characteristics (Note 1)
TQFN
Junction-to-Ambient Thermal Resistance (B
JA
) ..........29NC/W
Junction-to-Case Thermal Resistance (B
JC
) ..................1.7NC/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to
www.maximintegrated.com/thermal-tutorial.
DC Electrical Characteristics
(Measured using MAX2870 EV Kit. V
CC_
= 3V to 3.6V, V
GND_
= 0V, f
REF_IN
= 50MHz, f
PFD
= 25MHz, T
A
= -40NC to +85NC. Typical
values measured at V
CC_
= 3.3V; T
A
= +25NC; register settings (Reg 0:5) 00780000,20000141,01005E42,00000013,610F42
3C,01400005; unless otherwise noted.) (Note 2)
PARAMETER
Supply Voltage
RFOUT_ Current Consumption
I
RFOUT_
, minimum output power, single channel
I
RFOUT_
, maximum output power, single channel
Both channels
enabled,
maximum
output power
Total, including RFOUT, both
channel (Note 3)
Each output divide-by-2
I
CCVCO
+ I
CCRF
(Note 3)
Low-power sleep mode
CONDITIONS
MIN
3
TYP
3.3
8.5
25
144
10
75
29
180
15
95
1
mA
MAX
3.6
UNITS
V
mA
Supply Current
AC Electrical Characteristics
(Measured using MAX2870 EV Kit. V
CC_
= 3V to 3.6V, V
GND_
= 0V, f
REF_IN
= 50MHz, f
PFD
= 25MHz, f
RFOUT_
= 6000MHz,
T
A
= -40NC to +85NC. Typical values measured at V
CC_
= 3.3V, T
A
= +25NC, register settings (Reg 0:5) 00780000,20000141,01005E42
,00000013,610F423C,01400005; unless otherwise noted.) (Note 2)
PARAMETER
REFERENCE OSCILLATOR INPUT (REF_IN)
REF_IN Input Frequency Range
REF_IN Input Sensitivity
REF_IN Input Capacitance
REF_IN Input Current
PHASE DETECTOR
Phase Detector Frequency
Integer-N mode
Fractional-N mode
105
50
MHz
-60
10
0.7
2
+60
200
V
CC_
MHz
V
PP
pF
FA
CONDITIONS
MIN
TYP
MAX
UNITS
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│
2
MAX2870
23.5MHz to 6000MHz Fractional/
Integer-N Synthesizer/VCO
AC Electrical Characteristics
(continued)
(Measured using MAX2870 EV Kit. V
CC_
= 3V to 3.6V, V
GND_
= 0V, f
REF_IN
= 50MHz, f
PFD
= 25MHz, f
RFOUT_
= 6000MHz,
T
A
= -40NC to +85NC. Typical values measured at V
CC_
= 3.3V, T
A
= +25NC, register settings (Reg 0:5) 00780000,20000141,01005E42
,00000013,610F423C,01400005; unless otherwise noted.) (Note 2)
PARAMETER
CHARGE PUMP
Sink/Source Current
R
SET
Range
RF OUTPUTS
Fundamental Frequency Range
Divided Frequency Range
VCO Sensitivity
Frequency Pushing
Frequency Pulling
2nd Harmonic
3rd Harmonic
2nd Harmonic
3rd Harmonic
Maximum Output Power
Minimum Output Power
Output Power Variation (Note 4)
Muted Output Power
Open loop
Open loop into 2:1 VSWR
Fundamental VCO output
Fundamental VCO output
VCO output divided-by-2
VCO output divided-by-2
f
RFOUT_
= 3000MHz (Note 4)
f
RFOUT_
= 3000MHz (Note 4)
-40NC
P
T
A
P
+85NC
3V
P
V
CC_
P
3.6V
(Note 4)
10kHz offset
VCO at 3000MHz
100kHz offset
1MHz offset
5MHz offset
10kHz offset
VCO Phase Noise (Note 5)
VCO at 4500MHz
100kHz offset
1MHz offset
5MHz offset
10kHz offset
VCO at 6000MHz
100kHz offset
1MHz offset
5MHz offset
In-Band Noise Floor
1/f Noise
In-Band Phase Noise
Integrated RMS Jitter
Spurious Signals Due to PFD Frequency
VCO Tune Voltage
0.5
Normalized (Note 6)
Normalized (Note 7)
(Note 8)
(Note 9)
With output dividers (1/2/4/8/16/32/64/128)
3000
23.4375
100
0.7
70
40
34
20
21
5
-4
1.5
0.2
-31
-83.5
-111
-136
-149
-75
-104
-130
-145.5
-71.5
-100.5
-128.0
-143.5
-226.4
-116
-95
0.25
-87
2.5
dBc/Hz
dBc/Hz
dBc/Hz
ps
dBc
V
dBc/Hz
6000
6000
MHz
MHz
MHz/V
MHz/V
KHz
dBc
dBc
dBc
dBc
dBm
dBm
dB
dBm
CP[3:0] = 1111, R
SET
= 5.1kI
CP[3:0] = 0000, R
SET
= 5.1kI
2.7
5.12
0.32
10
mA
kI
CONDITIONS
MIN
TYP
MAX
UNITS
VCO AND FREQUENCY SYNTHESIZER NOISE
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Maxim Integrated
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3
MAX2870
23.5MHz to 6000MHz Fractional/
Integer-N Synthesizer/VCO
Digital I/O Characteristics
(V
CC_
= +3V to +3.6V, V
GND_
= 0V, T
A
= -40NC to +85NC. Typical values at V
CC_
= 3.3V, T
A
= +25NC.) (Note 2)
PARAMETER
Input Logic-Level Low
Input Logic-Level High
Input Current
Input Capacitance
SERIAL INTERFACE OUTPUTS (MUX_OUT, LD)
Output Logic-Level Low
Output Logic-Level High
Output Current Level High
0.3mA sink current
0.3mA source current
V
CC
- 0.4
0.5
0.4
V
V
mA
V
IL
V
IH
I
IH
/I
IL
1.5
-1
1
+1
CONDITIONS
MIN
TYP
MAX
0.4
UNITS
V
V
FA
pF
SERIAL INTERFACE INPUTS (CLK, DATA, LE, CE, RFOUT_EN)
SPI Timing Characteristics
(V
CC_
= +3V to +3.6V, V
GND_
= 0V, T
A
= -40NC to +85NC. Typical values at V
CC_
= 3.3V, T
A
= +25NC.) (Note 2)
PARAMETER
CLK Clock Period
CLK Pulse-Width Low
CLK Pulse-Width High
LE Setup Time
LE Hold Time
LE Minimum Pulse-Width High
Data Setup Time
Data Hold Time
MUX_OUT Setup Time
MUX_OUT Hold Time
SYMBOL
t
CP
t
CL
t
CH
t
LES
t
LEH
t
LEW
t
DS
t
DH
t
MS
t
MH
CONDITIONS
Guaranteed by SCL pulse-width
low and high
MIN
50
25
25
20
10
20
25
25
10
10
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Note 2:
Production tested at T
A
= +25NC. Cold and hot are guaranteed by design and characterization.
Note 3:
f
REFIN
= 100MHz, phase detector frequency = 25MHz, RF output = 6000MHz.
Register setting: 00780000, 20400061, 20011242, F8010003, 608001FC, 80440005
Note 4:
Measured single ended with 27nH to V
CC_RF
into 50I load. Power measured with single output enabled. Unused output
has 27nH to V
CC_RF
with 50I termination.
Note 5:
VCO phase noise is measured open loop.
Note 6:
Measured at 200kHz using a 50MHz Bliley NV108C19554 OCVCXO with 2MHz loop bandwidth. Register setting
801E0000, 8000FFF9, 80005FC2, 6C10000B, 638E80FC, 400005. EV kit loop filter: C13 = 1500pF, C14 = 33pF, R1 = 0Ω,
R2 = 1100Ω, R0 = 0Ω, C12 = open.
Note 7:
1/f noise contribution to the in-band phase noise is computed by using 1/fnoise + 10log(10kHz/f
OFFSET
) +
20log(f
RF
/1GHz). Register setting: 803A0000,8000FFF9,81005F42,F4000013,6384803C,001500005
Note 8:
f
REFIN
= 50MHz; f
PFD
= 25MHz; offset frequency = 10kHz; VCO frequency = 4227MHz, output divide-by-2 enabled.
RFOUT = 2113.5MHz; N = 169; loop BW = 40kHz, CP[3:0] = 1111; integer mode.
Note 9:
f
REFIN
= 50MHz; f
PFD
= 50MHz; VCO frequency = 4400MHz, f
RFOUT_
= 4400MHz; loop BW = 65kHz. Register setting:
002C0000, 200303E9, 80005642, 00000133, 638E82FC, 01400005. EV kit loop filter: C13 = 0.1µF, C14 = 0.012µF, R1 =
0Ω, R2 = 120Ω, R0 = 250Ω, C12 = 820pF.
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Maxim Integrated
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4
MAX2870
23.5MHz to 6000MHz Fractional/
Integer-N Synthesizer/VCO
Typical Operating Characteristics
(Measured with MAX2870 EV Kit. V
CC_
= 3.3V, V
GND_
= 0V, f
REF_IN
= 50MHz, T
A
= +25°C, see the Testing Conditions Table.)
3.0GHz VCO OPEN-LOOP PHASE NOISE
vs. FREQUENCY
MAX2780 toc01
4.5GHz VCO OPEN-LOOP PHASE NOISE
vs. FREQUENCY
MAX2780 toc02
6.0GHz VCO OPEN-LOOP PHASE NOISE
vs. FREQUENCY
MAX2780 toc03
-40
-50
PHASE NOISE (dBc/Hz)
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
1
10
100
1k
10k
-40
-50
PHASE NOISE (dBc/Hz)
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
1
10
100
1k
10k
-40
-50
PHASE NOISE (dBc/Hz)
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
1
10
100
1k
10k
100k
100k
100k
FREQUENCY (kHz)
FREQUENCY (kHz)
FREQUENCY (kHz)
3.0GHz CLOSED-LOOP PHASE NOISE
vs. FREQUENCY
MAX2780 toc04
4.5GHz CLOSED-LOOP PHASE NOISE
vs. FREQUENCY
MAX2780 toc05
6.0GHz CLOSED-LOOP PHASE NOISE
vs. FREQUENCY
-80
-90
PHASE NOISE (dBc/Hz)
-100
-110
-120
-130
-140
-150
-160
-170
DIV1
DIV2
DIV4
DIV8
DIV16
DIV32
DIV64
DIV128
MAX2780 toc06
MAX2780 toc09
-70
-80
-90
PHASE NOISE (dBc/Hz)
-100
-110
-120
-130
-140
-150
-160
-170
1
10
100
1k
10k
DIV1
DIV2
DIV4
DIV8
DIV16
DIV32
DIV64
DIV128
-70
-80
-90
PHASE NOISE (dBc/Hz)
-100
-110
-120
-130
-140
-150
-160
-170
DIV1
DIV2
DIV4
DIV8
DIV16
DIV32
DIV64
DIV128
-70
100k
1
10
100
1k
10k
100k
1
10
100
1k
10k
100k
FREQUENCY (kHz)
FREQUENCY (kHz)
FREQUENCY (kHz)
904MHz INTEGER-N MODE PHASE NOISE
AND SPUR PERFOMANCE vs. FREQUENCY
MAX2780 toc07
2687.5MHz INTEGER-N MODE PHASE NOISE
AND SPUR PERFOMANCE vs. FREQUENCY
MAX2780 toc08
2113.5MHz FRACTIONAL-N PHASE NOISE
(LOW-NOISE MODE) vs. FREQUENCY
-70
-80
-90
PHASE NOISE (dBc/Hz)
-100
-110
-120
-130
-140
-150
-160
-170
0
-20
PHASE NOISE (dBc/Hz)
SPURS (dBc)
-40
-60
-80
0
-20
PHASE NOISE (dBc/Hz)
SPURS (dBc)
-40
-60
-80
-100
-120
-140
-160
1
10
100
FREQUENCY (kHz)
1k
10k
-100
-120
-140
-160
1
10
100
FREQUENCY (kHz)
1k
10k
1
10
100
FREQUENCY (kHz)
1k
10k
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