19-4390; Rev 0; 2/09
TION KIT
EVALUA BLE
AVAILA
DOCSIS 3.0 Upstream Amplifier
Features
♦
+5V Supply Voltage
♦
Low Power: 1.25W at 31dB Gain, 64dBmV Output
♦
Ultra-Low 25mW Dissipation in Transmit-Disable
Mode
♦
63dB Gain Control Range in 1dB Steps
♦
-60dBc Harmonic Distortion at 64dBmV Output
♦
Small 5mm x 5mm Thin QFN Package
♦
Low Burst On/Off Transient
♦
275MHz, 3dB Bandwidth
General Description
The MAX3518 is an integrated CATV upstream ampli-
fier IC designed to meet the DOCSIS 3.0 requirements,
while disspating only 1.25W. The amplifier covers a
5MHz to 85MHz input frequency range (275MHz, 3dB
bandwidth), and is capable of transmitting four QPSK
modulated carriers, each at +58dBmV, simultaneously
within this range. Both input and output ports are dif-
ferential, requiring that an external balun be used at the
output port. The gain is controlled in 1dB steps over a
63dB range using a SPI™ 3-wire interface.
The MAX3518 operates from a single +5V supply. Four
power codes are provided to allow maximum supply
current to be reduced as determined by distortion
requirements. In addition, for each power code, sup-
ply current is automatically reduced as gain is reduced
while maintaining distortion performance. For DOCSIS
3.0 applications, the MAX3518 draws 300mA at 33dB
gain, dropping to 250mA at 31dB gain. The MAX3518
supply current drops to 5mA between bursts to minimize
power dissipation in transmit-disable mode. Control
logic levels are 3.3V CMOS.
The MAX3518 is available in a 20-pin thin QFN pack-
age, and operates over the extended industrial tem-
perature range (-40°C to +85°C).
MAX3518
Ordering Information
PART
TEMP RANGE
PIN PACKAGE
MAX3518ETP+
-40°C to +85°C
20 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Applications
DOCSIS 3.0 Cable Modems
VOIP Modems
Set-Top Boxes
SPI is a trademark of Motorola, Inc.
Typical Application Circuit appears at end of data sheet.
Pin Configuration/Functional Diagram
N.C.
20
GND
1
N.C.
19
N.C.
18
V
CC
17
N.C.
16
15
N.C.
MAX3518
IN+
2
14
OUT+
IN-
3
13
N.C.
N.C.*
4
SERIAL INTERFACE
12
OUT-
GND
5
11
N.C.*
NOTE:
N.C.* PINS MUST
BE LEFT UNCONNECTED.
6
SCLK
7
SDA
8
CS
9
TXEN
10
V
CC
_______________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or
visit Maxim’s website at www.maxim-ic.com.
DOCSIS 3.0 Upstream Amplifier
MAX3518
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND...........................................................-0.3V to +5.5V
IN+, IN- ...................................................... -0.3V to (V
CC
+ 0.3V)
OUT+, OUT-............................................... -0.3V to (V
CC
+ 3.6V)
TXEN, SDA, SCLK,
CS
.........................................-0.3V to +4.2V
RF Input Power ............................................................... +10dBm
Continuous Power Dissipation (T
A
= +70°C) (Note 1)
(derate 29mW/°C above T
A
= +70°C) ......................2000mW
Operating Temperature Range ......................... -40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ........................... -65°C to +165°C
Lead Temperature (soldering, 10s) .................................+300°C
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.maxim-ic.com/thermal-tutorial.
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
(Typical
Application Circuit
as shown, V
CC
= 4.75V to 5.25V, V
GND
= 0, TXEN = high, T
A
= -40°C to +85°C, unless otherwise speci-
fied. Typical values are at V
CC
= 5V, T
A
= +25°C.) (Note 2)
PARAMETER
Supply Voltage
Supply Current Transmit Mode
Supply Current Transmit
Disable Mode
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
SYMBOL
V
CC
I
CC
I
CC
V
INH
V
INL
I
BIASH
I
BIASH
CONDITIONS
Gain code = 63, power code = 3 (33dB gain typ)
Gain code = 59, power code = 1 (29dB gain typ)
TXEN = low
MIN
4.75
TYP
290
160
5
MAX
5.25
315
UNITS
V
mA
mA
V
V
µA
µA
6.5
3.6
0.7
10
2.0
-10
AC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit
as shown, V
CC
= 4.75V to 5.25V, V
GND
= 0, TXEN = high, T
A
= -40°C to +85°C, unless otherwise speci-
fied. Typical values are at V
CC
= 5V, T
A
= +25°C.) (Note 2)
PARAMETER
Frequency Range
SYMBOL
f
IN
(Note 3)
Gain code = 63
Gain code = 53
Gain code = 43
A
V
Gain code = 33
Gain code = 23
Gain code = 13
Gain code = 03
CONDITIONS
MIN
5
32
22
12
2
-8
-18
-28
TYP
33
23
13
3
-7
-17
-27
±0.1
MAX
85
34
24
14
4
-6
-16
-26
UNITS
MHz
Voltage Gain, Z
IN
= 200Ω,
Z
OUT
= 75Ω,
Power Code = 3
(Note 4)
dB
Voltage Gain Variation with
Power Code, Any Gain Code
Gain Rolloff
Gain Step Size
Voltage gain = -28dB to +33dB, f
IN
= 5MHz to
85MHz
Voltage gain = -28dB to +33dB, f
IN
= 5MHz to
85MHz
0.7
dB
dB
1.3
dB
-0.3
1.0
2
_______________________________________________________________________________________
DOCSIS 3.0 Upstream Amplifier
AC ELECTRICAL CHARACTERISTICS (continued)
(Typical
Application Circuit
as shown, V
CC
= 4.75V to 5.25V, V
GND
= 0, TXEN = high, T
A
= -40°C to +85°C, unless otherwise speci-
fied. Typical values are at V
CC
= 5V, T
A
= +25°C.) (Note 2)
MAX3518
Transmit-Disable Mode
Noise
Isolation in Transmit-Disable
Mode
Noise Figure
Noise Figure Slope
Transmit-Disable/Transmit-
Enable Transient Duration
Transmit-Disable/Transmit-
Enable Transient Step Size
Input Impedance
Input Return Loss
Output Return Loss
Output Return Loss in
Transmit-Disable Mode
2nd Harmonic Distortion
3rd Harmonic Distortion
Two-Tone 2nd-Order Distortion
Two-Tone 3rd-Order Distortion
Four Tone Spurs
Output 1dB Compression Point
P1dB
HD2
HD3
IM2
IM3
Z
IN
NF
Any BW = 160kHz from 5MHz to 85MHz, TXEN =
low, voltage gain = -27dB to +33dB (Note 5)
TXEN = low
Transmit mode, voltage gain = +13dB to +33dB
(Note 5)
Transmit mode, voltage gain = -27dB to +33dB
TXEN input rise/fall time < 0.1µs
Gain = 33dB
Gain = 4dB
Balanced
200Ω system
75Ω system (Note 5)
75Ω system, TXEN = low (Note 5)
Input tone at 33dBmV, V
OUT
= +64dBmV,
power code = 3 (Note 5)
Input tone at 33dBmV, V
OUT
= +64dBmV,
power code = 3 (Note 5)
Input tones at 30dBmV, V
OUT
= +61dBmV/tone,
power code = 3 (Note 5)
Input tones at 30dBmV, V
OUT
= +61dBmV/tone,
power code = 3 (Note 5)
Four input tones at 27dBmV,
V
OUT
= +58dBmV/tone, power code = 3
Gain = 33dB
11
11
-1.0
2
25
1
200
15
15
15
-70
-60
-70
-60
-55
74
80
-66
dBmV
dB
11
dB
dB/dB
µs
50
mV
P-P
W
dB
dB
dB
-57
-56
-57
-54
dBc
dBc
dBc
dBc
dBc
dBmV
TIMING CHARACTERISTICS
(Typical
Application Circuit
as shown, V
CC
= 4.75V to 5.25V, V
GND
= 0, T
A
= -40°C to +85°C, unless otherwise specified. Typical values
are at V
CC
= 5V, T
A
= +25°C.) (Note 2)
PARAMETER
SEN to SCK Rise Set Time
SEN to SCK Rise Hold Time
SDA to SCK Setup Time
SDA to SCK Hold Time
SCK Pulse-Width High
SCK Pulse-Width Low
Maximum CLK Frequency
Note
Note
Note
Note
2:
3:
4:
5:
SYMBOL
t
SENS
t
SENH
t
SDAS
t
SDAH
t
SCLKH
t
SCLKL
CONDITIONS
MIN
TYP
20
10
20
10
50
50
MAX
UNITS
ns
ns
ns
ns
ns
ns
MHz
10
Min/max values are production tested at T
A
= +85°C.
Production tested at 10MHz and 85MHz.
Voltage gain does not include loss due to input and output transformers.
Guaranteed by design and characterization.
________________________________________________________________________________________
3
DOCSIS 3.0 Upstream Amplifier
MAX3518
Typical Operating Characteristics
(MAX3518 EV kit, V
CC
= +5V, V
IN
= 33dBmV, f
IN
= 42MHz, Z
LOAD
= 75
Ω,
T
A
= +25°C, power code = 3, unless otherwise noted.)
SUPPLY CURRENT vs. GAIN CODE
MAX3518 toc01
SUPPLY CURRENT vs. TEMPERATURE
MAX3518 toc02
TRANSMIT DISABLE CURRENT
vs. TEMPERATURE
TXEN = LOW
5.0
SUPPLY CURRENT (mA)
4.9
4.8
4.7
4.6
4.5
4.4
MAX3518 toc03
350
300
SUPPLY CURRENT (mA)
250
200
150
100
PC = 1
50
0
0
10
20
30
40
GAIN CODE
50
PC = 0
60
PC = 2
PC = 3
301
300
SUPPLY CURRENT (mA)
V
CC
= +5.25V
299
298
297
296
295
V
CC
= +4.75V
V
CC
= +5.00V
5.1
70
-50
0
50
TEMPERATURE (°C)
100
4.3
-50
0
50
TEMPERATURE (°C)
100
VOLTAGE GAIN vs. TEMPERATURE
MAX3518 toc04
VOLTAGE GAIN vs. TEMPERATURE
MAX3518 toc05
GC = 63
GC = 53
GC = 43
GC = 33
GC = 23
GC = 13
GC = 3
30
20
33.5
VOLTAGE GAIN (dB)
VOLTAGE GAIN (dB)
PC = 0
33.0
PC = 3
32.5
PC = 2
VOLTAGE GAIN (dB)
V
CC
= +5.25V
33.5
PC = 1
10
0
-10
-20
-30
33.0
V
CC
= +5.00V
32.5
V
CC
= +4.75V
32.0
-50
0
50
TEMPERATURE (°C)
100
32.0
-50
0
50
TEMPERATURE (°C)
100
-40
0
100
200
300
FREQUENCY (MHz)
400
500
VOLTAGE GAIN vs. GAIN CODE
MAX3518 toc07
GAIN STEP SIZE vs. GAIN CODE
MAX3518 toc08
30
20
VOLTAGE GAIN (dB)
1.3
1.2
1.1
1.0
0.9
0.8
0.7
25
NOISE FIGURE (dB)
20
15
10
5
0
0
10
20
30
40
GAIN CODE
50
60
T
A
= +25°C
T
A
= -40°C
0
-10
-20
-30
-40
0
10
20
30
40
GAIN CODE
50
60
70
GAIN STEP (dB)
10
T
A
= +85°C
0.6
0
10
20
30
40
GAIN CODE
50
60
70
70
4
_______________________________________________________________________________________
MAX3518 toc09
40
1.4
NOISE FIGURE vs. GAIN CODE
30
MAX3518 toc06
34.0
34.0
VOLTAGE GAIN vs. FREQUENCY
40
DOCSIS 3.0 Upstream Amplifier
Typical Operating Characteristics (continued)
(MAX3518 EV kit, V
CC
= +5V, V
IN
= 33dBmV, f
IN
= 42MHz, Z
LOAD
= 75
Ω,
T
A
= +25°C, power code = 3, unless otherwise noted.)
2ND HARMONIC DISTORTION
vs. INPUT FREQUENCY
MAX3518 toc10
MAX3518
3RD HARMONIC DISTORTION
vs. INPUT FREQUENCY
MAX3518 toc11
-55
2ND HARMONIC DISTORTION (dBc)
-60
-65
-70
-75
-80
-85
-90
-95
-100
0
P
OUT
= +64dBmV, P
DISS
= 1.25W
T
A
= +85°C
-52
3RD HARMONIC DISTORTION (dBc)
-54
-56
-58
-60
-62
-64
-66
-68
-70
P
OUT
= +64dBmV, P
DISS
= 1.25W
-55
-60
-65
IM2 (dBc)
-70
-75
-80
-85
-90
-95
-100
0
P
OUT
= +61dBmV/TONE, P
DISS
= 1.25W
1MHz TONE SPACING
T
A
= +85°C
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
T
A
= -40°C
T
A
= +25°C
T
A
= -40°C
T
A
= +25°C
10 20 30 40 50 60 70 80 90 100
FREQUENCY (MHz)
0
10 20 30 40 50 60 70 80 90 100
INPUT FREQUENCY (MHz)
10 20 30 40 50 60 70 80 90 100
FREQUENCY (MHz)
IM3 vs. INPUT FREQUENCY
(2f
1
- f
2
)
-52
-54
-56
IM3 (dBc)
-58
-60
-62
-64
-66
-68
-70
0
10 20 30 40 50 60 70 80 90 100
FREQUENCY (MHz)
T
A
= +25°C
T
A
= +85°C
T
A
= -40°C
P
OUT
= +61dBmV/TONE, P
DISS
= 1.25W
1MHz TONE SPACING
MAX3518 toc13
TXEN TRANSIENT vs. GAIN CODE
35
TXEN TRANSIENT (mV
P-P
)
30
25
20
15
10
5
0
0
10
20
30
40
GAIN CODE
50
60
70
MAX3518 toc14
-50
40
OUTPUT RETURN LOSS vs. FREQUENCY
MAX3518 toc15
OUTPUT RETURN LOSS vs. FREQUENCY
(TRANSMIT DISABLE MODE)
MAX3518 toc16
0
0
OUTPUT RETURN LOSS (dB)
OUTPUT RETURN LOSS (dB)
-5
-5
-10
T
A
= -40°C
-15
T
A
= +85°C
0
T
A
= +25°C
-10
T
A
= -40°C
-15
T
A
= +85°C
0
T
A
= +25°C
-20
20 40 60 80 100 120 140 160 180 200
FREQUENCY (MHz)
-20
20 40 60 80 100 120 140 160 180 200
FREQUENCY (MHz)
________________________________________________________________________________________
MAX3518 toc12
-50
-50
IM2 vs. INPUT FREQUENCY
(f
1
+ f
2
)
-50
5
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