MAXIM MAX2473EUT-T

19-1466; Rev 0; 6/99
ANUAL
N KIT M EET
IO
T
A
U
EVAL
TA SH
WS DA
FOLLO
500MHz to 2500MHz
VCO Buffer Amplifiers
The MAX2472/MAX2473 are flexible, wideband, highreverse-isolation buffer amplifiers. The MAX2472 has dual
open-collector outputs capable of delivering -5dBm into
50Ω while maintaining harmonic suppression below
-25dBc. The MAX2473 has a single open-collector output
with a bias control pin to vary output power from -10dBm
to -2dBm while maintaining harmonic suppression below
-25dBc. The MAX2472/MAX2473’s combination of high
reverse isolation and low supply current makes them ideal
for applications requiring high performance with low
power. They feature high input impedance and open-collector outputs for maximum flexibility, enabling them to be
used with a variety of oscillator topologies.
Both the MAX2472 and MAX2473 operate from a single
+2.7V to +5.5V supply. With VCC = +3.0V and -25dBm
input power, the MAX2472 consumes 5.2mA, while the
MAX2473 consumes only 2.7mA. Both devices are available in a tiny 6-pin SOT23 package requiring minimal
board space.
Features
♦ +2.7V to +5.5V Supply Range
♦ 500MHz to 2500MHz Input Frequency Range
♦ High Reverse Isolation: 49dB at 900MHz
♦ Dual Open-Collector Outputs (MAX2472)
♦ Adjustable -10dBm to -2dBm Output Power
Control (MAX2473)
♦ High Input Impedance: >250Ω at 900MHz
♦ Ultra-Small SOT23-6 Package
Ordering Information
PART
TEMP.
RANGE
PINPACKAGE
SOT
TOP MARK
MAX2472EUT-T -40°C to +85°C
6 SOT23-6
AAAZ
MAX2473EUT-T -40°C to +85°C
6 SOT23-6
AABA
Applications
Functional Diagrams
Cellular and PCS Mobile Phones
Private Mobile Radios
VCC
ISM-Band Applications
BIAS
IF/RF Oscillators
OUT2
General-Purpose Buffers/Amplifiers
MAX2472
IN
Typical Operating Circuits appear at end of data sheet.
OUT1
GND
Pin Configuration
GND
VCC
TOP VIEW
BIAS
BIAS
OUT1 (OUT) 1
6
VCC
MAX2473
GND 2
MAX2472
MAX2473
OUT2 (BIAS) 3
5
GND
OUT
IN
4
IN
GND
GND
SOT23-6
( ) ARE FOR MAX2473.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX2472/MAX2473
General Description
MAX2472/MAX2473
500MHz to 2500MHz
VCO Buffer Amplifiers
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.3V to +7V
OUT1, OUT2, BIAS to GND........................-0.3V to (VCC + 0.3V)
Maximum BIAS Pin Current................................................150µA
Maximum Input Power....................................................+10dBm
Continuous Power Dissipation
SOT23-6 (derate 8.7mW/°C above +70°C)...................696mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°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.
DC ELECTRICAL CHARACTERISTICS
(VCC = +2.7V to +5.5V, PIN = -25dBm, IN driven from a 50Ω source, OUT_ LC-matched to 50Ω, TA = TMIN to TMAX, unless otherwise
noted. Typical values are at VCC = +3V, TA = +25°C.) (Note 1)
PARAMETER
Input Voltage Range
Supply Current
SYMBOL
CONDITIONS
VCC
ICC
MIN
TYP
2.7
MAX2472
5.2
MAX2473, RBIAS = 23kΩ
2.7
MAX2473, RBIAS = 11kΩ
4.8
No drive
MAX2472
5.1
MAX2473, RBIAS = 23kΩ
2.5
MAX2473, RBIAS = 11kΩ
4.3
MAX
UNITS
5.5
V
8.0
mA
AC ELECTRICAL CHARACTERISTICS—MAX2472
(Typical Operating Circuits, VCC = +3V, PIN = -25dBm, IN driven from a 50Ω source, OUT1 and OUT2 LC matched to 50Ω, TA =
+25°C, unless otherwise noted.)
PARAMETER
SYMBOL
Input Frequency Range (Note 2)
fIN
CONDITIONS
MIN
500
fIN = 600MHz
Transducer Gain
(IN to OUT2)
S212
Output 1dB Compression Point
Reverse Isolation
(IN to OUT2)
2
S212
POUT1dB
S122
MAX
UNITS
2500
MHz
14.0
fIN = 900MHz, TA = +25°C
7.8
fIN = 900MHz, TA = TMIN to TMAX (Note 3)
6.6
fIN = 1900MHz
Transducer Gain
(IN to OUT1)
TYP
10.2
12.2
14.6
dB
7.5
fIN = 2400MHz
6.0
fIN = 600MHz
13.0
fIN = 900MHz
9.2
fIN = 1900MHz
6.8
fIN = 2400MHz
5.3
fIN = 900MHz
-3.2
fIN = 600MHz
43
fIN = 900MHz
40
fIN = 1900MHz
30
fIN = 2400MHz
26
_______________________________________________________________________________________
dB
dBm
dB
500MHz to 2500MHz
VCO Buffer Amplifiers
(Typical Operating Circuits, VCC = +3V, PIN = -25dBm, IN driven from a 50Ω source, OUT1 and OUT2 LC matched to 50Ω, TA =
+25°C, unless otherwise noted.)
PARAMETER
Reverse Isolation
(IN to OUT1)
SYMBOL
S122
Noise Figure
NF
CONDITIONS
MIN
TYP
fIN = 600MHz
54
fIN = 900MHz
49
fIN = 1900MHz
34
fIN = 2400MHz
30
fIN = 900MHz
9.5
fIN = 1900MHz
10.2
MAX
UNITS
dB
dB
Isolation (OUT1 to OUT2)
fIN = 900MHz
24
dB
Harmonic Suppression
POUT = -5dBm, fIN = 900MHz
-25
dBc
AC ELECTRICAL CHARACTERISTICS—MAX2473
(Typical Operating Circuits, VCC = +3V, PIN = -25dBm, RBIAS = 15kΩ, IN driven from a 50Ω source, OUT LC matched to 50Ω, TA =
+25°C, unless otherwise noted.)
PARAMETER
SYMBOL
Input Frequency Range (Note 2)
fIN
CONDITIONS
MIN
500
fIN = 600MHz
S212
Transducer Gain
fIN = 900MHz, TA = +25°C
6.8
fIN = 900MHz, TA = TMIN to TMAX (Note 3)
6.4
S122
Reverse Isolation
Noise Figure
NF
Harmonic Suppression
fIN = 900MHz
UNITS
2500
MHz
11.8
16.8
19.0
dB
7.6
fIN = 2400MHz
POUT1dB
MAX
14.8
fIN = 1900MHz
Output 1dB Compression Point
TYP
7.2
RBIAS = 23kΩ
-6.0
RBIAS = 11kΩ
-0.9
fIN = 600MHz
50
fIN = 900MHz
48
fIN = 1900MHz
35
fIN = 2400MHz
29
fIN = 900MHz
9.2
fIN = 1900MHz
9.9
POUT = -5dBm, fIN = 900MHz
-25
dBm
dB
dB
dBc
Note 1: Limits are 100% production tested at TA = +25°C. Limits over the entire operating temperature range are guaranteed by
design and characterization but are not production tested.
Note 2: This is the recommended operating frequency range. The parts have been characterized over the specified frequency
range and production tested at 900MHz. Operation outside of this range is possible but not guaranteed.
Note 3: Guaranteed by design and characterization.
_______________________________________________________________________________________
3
MAX2472/MAX2473
AC ELECTRICAL CHARACTERISTICS—MAX2472 (continued)
Typical Operating Characteristics
(MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25°C, unless otherwise noted.)
MAX2472
MAX2472 toc01
PIN = -20dBm
fIN = 900MHz
12
10
S21 2 (dB)
6.0
VCC = 5V
ICC (mA)
PIN = -20dBm
fIN = 600MHz
14
MAX2472 toc02
S21 2 vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
7.0
VCC = 3V
8
fIN = 900MHz
fIN = 1900MHz
6
5.0
4
fIN = 2400MHz
2
-20
0
20
40
60
0
-50
80
-30
-10
10
30
50
TEMPERATURE (°C)
TEMPERATURE (°C)
S21 2 vs. OUTPUT POWER
S11
90
MAX2472 toc03
14
70
fIN = 600MHz
12
MAX2472 toc06
4.0
-40
10
S21 2 (dB)
fIN = 900MHz
fIN = 1900MHz
8
6
A
fIN = 2400MHz
D
4
FOR OUT1 WITH OUT2 REACTIVELY
MATCHED AND TERMINATED
0
-20 -18 -16 -14 -12 -10 -8
-6
-4
-2
0
FOR OUT2 WITH OUT1 BIASED
AND TERMINATED
POUT (dBm)
S21
B
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
S22
S12
MAX2472 toc08
MAX2472 toc09
2
C
MAX2472 toc07
MAX2472/MAX2473
500MHz to 2500MHz
VCO Buffer Amplifiers
D
BA
C
D
A
C
B
D
B
C
A
(3 UNITS FULL SCALE)
FOR OUT2 WITH OUT1 BIASED
AND TERMINATED
4
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
(0.1 UNITS FULL SCALE)
FOR OUT2 WITH OUT1 BIASED
AND TERMINATED
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
FOR OUT2 WITH OUT1 BIASED
AND TERMINATED
_______________________________________________________________________________________
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
500MHz to 2500MHz
VCO Buffer Amplifiers
MAX2472
SCATTERING PARAMETERS
(IN to OUT 2)
_______________________________________________________________________________________
5
MAX2472/MAX2473
Typical Operating Characteristics (continued)
(MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25°C, unless otherwise noted.)
MAX2473
14
7
VCC = 5V
5
14
fIN = 900MHz
10
8
fIN = 1900MHz
VCC = 3V
2
fIN = 2400MHz
35
30
25
20
15
0
-50
10
-25
S21 2 vs. OUTPUT POWER
fIN = 1900MHz
16
18
12
S21 2 (dB)
14
RBIAS = 11kΩ
8
-15
0
-25
100
18
10
RBIAS = 15kΩ
-10
POUT (dBm)
RBIAS = 22kΩ
8
2
-4
RBIAS = 15kΩ
10
0
-20
-8
RBIAS = 11kΩ
12
4
-12
fIN = 600MHz
6
RBIAS = 22kΩ
-16
0
14
2
0
-5
16
RBIAS = 22kΩ
-5
-10
S21 2 vs. OUTPUT POWER
RBIAS = 11kΩ
8
-15
20
4
POUT (dBm)
-20
POUT (dBm)
fIN = 900MHz
6
RBIAS = 15kΩ
4
0
-20
75
16
12
2
50
S21 2 vs. OUTPUT POWER
14
6
25
20
MAX2472 toc13b
20
10
RBIAS = 22kΩ
TEMPERATURE (°C)
RBIAS (kΩ)
18
0
S21 2 (dB)
40
RBIAS = 15kΩ
2
MAX2472 toc13c
45
RBIAS = 11kΩ
4
2
50
10
6
4
1
12
8
6
3
fIN = 2400MHz
16
S21 2 (dB)
6
4
6
18
12
S21 2 (dB)
ICC (mA)
fIN = 600MHz
MAX2472 toc13a
8
PIN = -20dBm
RBIAS = 15kΩ
16
20
MAX2472 toc12
18
MAX2472 toc11
9
0
S21 2 vs. OUTPUT POWER
S21 2 vs. TEMPERATURE
10
MAX2472 toc13d
SUPPLY CURRENT
vs. RBIAS
S21 2 (dB)
MAX2472/MAX2473
500MHz to 2500MHz
VCO Buffer Amplifiers
0
0
-20
-15
-10
-5
POUT (dBm)
_______________________________________________________________________________________
0
5
500MHz to 2500MHz
VCO Buffer Amplifiers
MAX2473
S11
MAX2472 toc15
-30
fIN = 900MHz
-35
REVERSE ISOLATION (dB)
MAX2472 toc16
REVERSE ISOLATION vs. RBIAS
-40
-45
D
-50
A
B
C
-55
-60
0
5
10
15
20
25
30
35
RBIAS = 15kΩ
40
RBIAS (kΩ)
S21
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
S22
MAX2472 toc19
MAX2472 toc17
MAX2472 toc18
S12
D
A
C B
A
D
B
C
(3 UNITS FULL SCALE)
RBIAS = 15kΩ
D
B
A
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
C
(0.1 UNITS FULL SCALE)
RBIAS = 15kΩ
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
RBIAS = 15kΩ
A: fIN = 600MHz
B: fIN = 900MHz
C: fIN = 1900MHz
D: fIN = 2400MHz
_______________________________________________________________________________________
7
MAX2472/MAX2473
Typical Operating Characteristics (continued)
(MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25°C, unless otherwise noted.)
MAX2472/MAX2473
500MHz to 2500MHz
VCO Buffer Amplifiers
Typical Operating Characteristics (continued)
(MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25°C, unless otherwise noted.)
MAX2473
SCATTERING PARAMETERS
(IN to OUT)
8
_______________________________________________________________________________________
500MHz to 2500MHz
VCO Buffer Amplifiers
PIN
NAME
FUNCTION
MAX2472
MAX2473
1
—
OUT1
Open-Collector Buffer Output 1. Connect to VCC via a resistor or
inductor/choke. AC-coupling to the output is required.
—
1
OUT
Open-Collector Buffer Output. Connect to VCC via a resistor or
inductor/choke. AC-coupling to the output is required.
2, 5
2, 5
GND
RF Ground. Connect to the ground plane as close to the IC as possible to
minimize trace inductance.
3
—
OUT2
Open-Collector Buffer Output 2. Connect to VCC via a resistor or
inductor/choke. AC-coupling to the output is required.
—
3
BIAS
Bias Resistor Connection. Connect a resistor from BIAS to GND to set the
output stage bias current and gain. To choose RBIAS, refer to the Typical
Operating Characteristics for the MAX2473.
4
4
IN
High-Impedance Input to the Buffer Amplifier
6
6
VCC
Supply Voltage Input: +2.7V < VCC < +5.5V
Table 1. Output Matching Components
OPERATING
FREQUENCY
(MHz)
LMATCH
CMATCH
600
22nH
Coilcraft 0603HS-22NTJBC
1.5pF
Murata GRM39COG1R5B50V
900
12nH
Coilcraft 0603HS-12NTJBC
1pF
Murata GRM39COG1R0B50V
1900
2.2nH
Murata LQG11AZN2500
1pF
Murata GRM39COG1R0B50V
2400
1.2nH
Murata LQG11AINZS00
1pF
Murata GRM39COG1R0B50V
Detailed Description
The MAX2472/MAX2473 are ideal replacements for discrete solutions where a VCO output must drive more
than one input, especially where high reverse isolation
and low supply currents are mandatory. The MAX2472
features a two-stage wideband architecture with a highinput-impedance common-emitter amplifier followed by
two separate open-collector output stages. The
MAX2473 features a two-stage wideband architecture
with a high-input-impedance common-emitter amplifier
followed by one open-collector output stage, with the
added feature of output power control. Using values for
RBIAS from 11kΩ to 23kΩ allows the output power of
the MAX2473 to range from -2dBm to -10dBm.
_______________________________________________________________________________________
9
MAX2472/MAX2473
Pin Description
MAX2472/MAX2473
500MHz to 2500MHz
VCO Buffer Amplifiers
VCC
(PIN 6)
VCC
(PIN 6)
INTERNAL
1.2V
REFERENCE
250Ω
1.3pF
1k
1k
BIAS
(PIN 3)
IN
(PIN 4)
GND
(PIN 2)
33Ω
Figure 3. BIAS Structure (MAX2473 only)
GND
(PIN 5)
Figure 1. Input Structure
VCC
(PIN 6)
2k
OUT
the MAX2472/MAX2473 from the S parameter tables in
the Typical Operating Characteristics. Terminate the
buffer input with a shunt resistor “RTERM” such that
RTERM || RE[S11] = 50Ω, and use a series blocking
capacitor between the shunt resistor and the device
input. This provides a very stable 50Ω termination and
increases reverse isolation. For those applications
needing both high gain and good input match, reactively match the buffer inputs to 50Ω with simple twoelement matching circuits. Figure 1 shows an equivalent
input circuit of the MAX2472/MAX2473 IN pin.
Output Considerations
10Ω
GND
(PIN 2)
Figure 2. Output Structure
Applications Information
Input Considerations
The MAX2472/MAX2473 offer high-impedance inputs
ideal for low-distortion buffering of a VCO. For applications with discrete transistor-based oscillator designs,
simply AC-couple the oscillator directly to the input; the
buffer’s high input impedance results in minimal loading on the oscillator. For use with 50Ω VCO modules,
determine the approximate input impedance (S11) of
10
The MAX2472/MAX2473 outputs are configured as
open-collector output stages, allowing maximum flexibility. To achieve maximum gain and output drive, reactively match these outputs with a shunt inductor/choke
to VCC followed by a series capacitor (DC block). For
applications not requiring high gain and output drive
(PLL prescaler), use a simple resistor to VCC followed
by a DC blocking capacitor. Figure 2 shows an equivalent circuit of the MAX2472/MAX2473 OUT pin(s).
Figure 3 shows an equivalent circuit of the MAX2473
BIAS pin.
Output Matching Circuit
Table 1 lists recommended values for lumped-element
output matching circuits at certain frequencies. For frequencies other than those specified, use the parameters given in the Typical Operating Characteristics.
Layout and Power-Supply Bypassing
A properly designed PC board is essential to any
RF/microwave circuit. Be sure to use controlled impedance lines on all high-frequency inputs and outputs.
Bypass the power supply with decoupling capacitors
______________________________________________________________________________________
500MHz to 2500MHz
VCO Buffer Amplifiers
uses a topside RF ground, connect both GND pins
directly to it. For a board where the ground plane is not
on the component side, the best technique is to connect the GND pins to the board with plated throughholes (vias) to the ground plane, located as close to the
package as possible.
Typical Operating Circuits
VCC
VCC
0.01µF
30pF
1.0µF
0.01µF
VCC
LMATCH
BIAS
TO MIXER
CMATCH
OUT2
MAX2472
VCO
IN
OUT1
100pF
CMATCH
TO MIXER OR PLL
GND
GND
LMATCH
0.01µF
30pF
VCC
VCC
1.0µF
0.01µF
RBIAS
VCC
BIAS
BIAS
MAX2473
VCO
IN
TO
MIXER
CMATCH
100pF
GND
LMATCH
GND
30pF
0.01µF
VCC
______________________________________________________________________________________
11
MAX2472/MAX2473
as close to the VCC pin as possible. For long VCC lines
(inductive), it may be necessary to add additional
decoupling capacitors located farther away from the
device package.
Proper connection of the GND pins is essential to
achieving maximum reverse isolation. If the PC board
500MHz to 2500MHz
VCO Buffer Amplifiers
6LSOT.EPS
MAX2472/MAX2473
Package Information
Chip Information
TRANSISTOR COUNT: 109
12
______________________________________________________________________________________