MAX2680EUT [MAXIM]
400MHz to 2.5GHz, Low-Noise, SiGe Downconverter Mixers; 400MHz至2.5GHz的，低噪声， SiGe下变频混频器
| 型号： | MAX2680EUT |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 400MHz to 2.5GHz, Low-Noise, SiGe Downconverter Mixers |
| 文件： | 总11页 (文件大小：187K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-4786; Rev 2; 8/03
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
General Description
Features
The MAX2680/MAX2681/MAX2682 miniature, low-cost,
low-noise downconverter mixers are designed for low-
voltage operation and are ideal for use in portable com-
munications equipment. Signals at the RF input port are
mixed with signals at the local oscillator (LO) port using a
double-balanced mixer. These downconverter mixers
operate with RF input frequencies between 400MHz and
2500MHz, and downconvert to IF output frequencies
between 10MHz and 500MHz.
ꢀ 400MHz to 2.5GHz Operation
ꢀ +2.7V to +5.5V Single-Supply Operation
ꢀ Low Noise Figure: 6.3dB at 900MHz (MAX2680)
ꢀ High Input Third-Order Intercept Point
(IIP3 at 2450MHz)
-6.9dBm at 5.0mA (MAX2680)
+1.0dBm at 8.7mA (MAX2681)
+3.2dBm at 15.0mA (MAX2682)
The MAX2680/MAX2681/MAX2682 operate from a sin-
gle +2.7V to +5.5V supply, allowing them to be pow-
ered directly from a 3-cell NiCd or a 1-cell Lithium
battery. These devices offer a wide range of supply
currents and input intercept (IIP3) levels to optimize
system performance. Additionally, each device features
a low-power shutdown mode in which it typically draws
less than 0.1µA of supply current. Consult the Selector
Guide for various combinations of IIP3 and supply cur-
rent.
ꢀ <0.1µA Low-Power Shutdown Mode
ꢀ Ultra-Small Surface-Mount Packaging
Ordering Information
PIN-
SOT
PART
TEMP RANGE
PACKAGE TOP MARK
The MAX2680/MAX2681/MAX2682 are manufactured
on a high-frequency, low-noise, advanced silicon-ger-
manium process and are offered in the space-saving
6-pin SOT23 package.
MAX2680EUT-T -40°C to +85°C 6 SOT23-6
MAX2681EUT-T -40°C to +85°C 6 SOT23-6
MAX2682EUT-T -40°C to +85°C 6 SOT23-6
AAAR
AAAS
AAAT
Pin Configuration
Applications
400MHz/900MHz/2.4GHz ISM-Band Radios
Personal Communications Systems (PCS)
Cellular and Cordless Phones
TOP VIEW
LO
GND
RFIN
1
2
3
6
5
4
SHDN
Wireless Local Loop
MAX2680
MAX2681
MAX2682
IEEE-802.11 and Wireless Data
V
CC
IFOUT
SOT23-6
Typical Operating Circuit appears at end of data sheet.
Selector Guide
FREQUENCY
1950MHz
900MHz
2450MHz
I
CC
PART
(mA)
IIP3
(dBm)
NF
(dB)
GAIN
(dB)
IIP3
(dBm)
NF
(dB)
GAIN
(dB)
IIP3
(dBm)
NF
(dB)
GAIN
(dB)
MAX2680
MAX2681
MAX2682
5.0
8.7
-12.9
-6.1
6.3
7.0
6.5
11.6
14.2
14.7
-8.2
+0.5
+4.4
8.3
7.6
8.4
-6.9
+1.0
+3.2
11.7
12.7
13.4
7.0
7.7
7.9
11.1
10.2
15.0
-1.8
10.4
________________________________________________________________ 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.
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
ABSOLUTE MAXIMUM RATINGS
CC
V
to GND ..........................................................-0.3V to +6.0V
Continuous Power Dissipation (T = +70°C)
A
RFIN Input Power (50Ω Source).....................................+10dBm
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 +160°C
Lead Temperature (soldering, 10s) .................................+300°C
LO Input Power (50Ω Source)........................................+10dBm
SHDN, IFOUT, RFIN to GND ......................-0.3V to (V
+ 0.3V)
+ 0.3V)
CC
CC
LO to GND..........................................(V
- 1V) to (V
CC
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
(V
= +2.7V to +5.5V, SHDN = +2V, T = T
to T
unless otherwise noted. Typical values are at V = +3V and T = +25°C.
CC A
CC
A
MIN
MAX
Minimum and maximum values are guaranteed over temperature by design and characterization.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
7.7
UNITS
MAX2680
MAX2681
MAX2682
SHDN = 0.5V
5.0
8.7
Operating Supply Current
I
I
12.7
21.8
5
mA
CC
15.0
0.05
Shutdown Supply Current
Shutdown Input Voltage High
Shutdown Input Voltage Low
Shutdown Input Bias Current
µA
V
CC
V
IH
2.0
V
0.5
V
IL
SHDN
I
0.2
µA
0 < SHDN < V
CC
AC ELECTRICAL CHARACTERISTICS
(MAX2680/1/2 EV Kit, V
= SHDN = +3.0V, T = +25°C, unless otherwise noted. RFIN and IFOUT matched to 50Ω. P = -5dBm,
CC
A
LO
P
= -25dBm.)
RFIN
PARAMETER
MAX2680
CONDITIONS
MIN
TYP
MAX
UNITS
RF Frequency Range
LO Frequency Range
IF Frequency Range
(Notes 1, 2)
(Notes 1, 2)
(Notes 1, 2)
400
400
10
2500
2500
500
MHz
MHz
MHz
f
f
f
f
= 400MHz, f = 445MHz, f = 45MHz
7.3
11.6
7.6
RF
RF
RF
RF
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Conversion Power Gain
dB
= 1950MHz, f = 1880MHz, f = 70MHz (Note 1)
5.7
8.6
2.4
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
7.0
LO
IF
f
RF
= 1950MHz, f = 1880MHz, f = 70MHz,
LO IF
Gain Variation Over Temperature
1.9
dB
T
= T
to T
(Note 1)
A
MIN
MAX
f
f
f
f
f
f
= 900MHz, 901MHz, f = 970MHz, f = 70MHz
-12.9
-8.2
-6.9
6.3
RF
RF
RF
RF
RF
RF
LO
IF
Input Third-Order Intercept Point
(Note 3)
= 1950MHz, 1951MHz, f = 1880MHz, f = 70MHz
dBm
LO
IF
= 2450MHz, 2451MHz, f = 2210MHz, f = 240MHz
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Noise Figure (Single Sideband)
= 1950MHz, f = 2020MHz, f = 70MHz
8.3
dB
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
11.7
1.5:1
-22
LO
IF
LO Input VSWR
50Ω source impedance
= 1880MHz
LO Leakage at IFOUT Port
f
dBm
LO
2
_______________________________________________________________________________________
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2680/1/2 EV Kit, V
= SHDN = +3.0V, T = +25°C, unless otherwise noted. RFIN and IFOUT matched to 50Ω. P = -5dBm,
CC
A
LO
P
= -25dBm.)
RFIN
PARAMETER
CONDITIONS
MIN
TYP
-26
MAX
UNITS
dBm
LO Leakage at RFIN Port
IF/2 Spurious Response
MAX2681
f
f
= 1880MHz
LO
= 1915MHz, f = 1880MHz, f = 70MHz (Note 4)
-51
dBm
RF
LO
IF
RF Frequency Range
LO Frequency Range
IF Frequency Range
(Notes 1, 2)
(Notes 1, 2)
(Notes 1, 2)
400
400
10
2500
2500
500
MHz
MHz
MHz
f
f
f
f
= 400MHz, f = 445MHz, f = 45MHz
11.0
14.2
8.4
RF
RF
RF
RF
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Conversion Power Gain
dB
= 1950MHz, f = 1880MHz, f = 70MHz (Note 1)
6.7
9.4
2.3
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
7.7
LO
IF
f
RF
= 1950MHz, f = 1880MHz, f = 70MHz,
LO IF
Gain Variation Over Temperature
1.7
dB
T
= T
to T
(Note 1)
A
MIN
MAX
f
f
f
f
f
f
= 900MHz, 901MHz, f = 970MHz, f = 70MHz
-6.1
+0.5
+1.0
7.0
RF
RF
RF
RF
RF
RF
LO
IF
Input Third-Order Intercept Point
(Note 3)
= 1950MHz, 1951MHz, f = 1880MHz, f = 70MHz
dBm
LO
IF
= 2450MHz, 2451MHz, f = 2210MHz, f = 240MHz
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Noise Figure (Single Sideband)
= 1950MHz, f = 2020MHz, f = 70MHz
11.1
12.7
1.5:1
-23
dB
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
LO
IF
LO Input VSWR
50Ω source impedance
LO Leakage at IFOUT Port
LO Leakage at RFIN Port
IF/2 Spurious Response
MAX2682
f
f
f
= 1880MHz
= 1880MHz
dBm
dBm
dBm
LO
LO
RF
-27
= 1915MHz, f = 1880MHz, f = 70MHz (Note 4)
-65
LO
IF
RF Frequency Range
LO Frequency Range
IF Frequency Range
(Notes 1, 2)
(Notes 1, 2)
(Notes 1, 2)
400
400
10
2500
2500
500
MHz
MHz
MHz
f
f
f
f
= 400MHz, f = 445MHz, f = 45MHz
13.4
14.7
10.4
7.9
RF
RF
RF
RF
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Conversion Power Gain
dB
= 1950MHz, f = 1880MHz, f = 70MHz (Note 1)
8.7
11.7
3.2
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
LO
IF
f
RF
= 1950MHz, f = 1880MHz, f = 70MHz,
LO IF
Gain Variation Over Temperature
2.1
dB
T
= T
to T
(Note 1)
A
MIN
MAX
f
RF
f
RF
f
RF
f
RF
f
RF
f
RF
= 900MHz, 901MHz, f = 970MHz, f = 70MHz
-1.8
+4.4
+3.2
6.5
LO
IF
Input Third-Order Intercept Point
(Note 3)
= 1950MHz, 1951MHz, f = 1880MHz, f = 70MHz
dBm
LO
IF
= 2450MHz, 2451MHz, f = 2210MHz, f = 240MHz
LO
IF
= 900MHz, f = 970MHz, f = 70MHz
LO
IF
Noise Figure (Single Sideband)
= 1950MHz, f = 2020MHz, f = 70MHz
10.2
13.4
dB
LO
IF
= 2450MHz, f = 2210MHz, f = 240MHz
LO
IF
_______________________________________________________________________________________
3
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2680/1/2 EV Kit, V
= SHDN = +3.0V, T = +25°C, unless otherwise noted. RFIN and IFOUT matched to 50Ω. P = -5dBm,
A LO
CC
P
RFIN
= -25dBm.)
PARAMETER
LO Input VSWR
CONDITIONS
50Ω source impedance
MIN
TYP
1.5:1
-23
MAX
UNITS
LO Leakage at IFOUT Port
LO Leakage at RFIN Port
IF/2 Spurious Response
f
f
f
= 1880MHz
= 1880MHz
dBm
dBm
dBm
LO
LO
RF
-27
= 1915MHz, f = 1880MHz, f = 70MHz (Note 4)
-61
LO
IF
Note 1: Guaranteed by design and characterization.
Note 2: Operation outside of this specification is possible, but performance is not characterized and is not guaranteed.
Note 3: Two input tones at -25dBm per tone.
Note 4: This spurious response is caused by a higher-order mixing product (2x2). Specified RF frequency is applied and IF output
power is observed at the desired IF frequency (70MHz).
Typical Operating Characteristics
(Typical Operating Circuit, V
= SHDN = +3.0V, P
= -25dBm, P = -5dBm, T = +25°C, unless otherwise noted.)
RFIN LO A
CC
MAX2680
MAX2681
MAX2682
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
18
17
16
15
14
13
12
11
10
9
7
6
5
4
3
2
10
9
SHDN = V
CC
SHDN = V
CC
SHDN = V
CC
T
= +85°C
A
T
= +85°C
A
T
= +85°C
A
T
= +25°C
= -40°C
A
8
T
= +25°C
A
T
= +25°C
A
T
= -40°C
A
T
= -40°C
A
7
T
A
6
5
8
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Typical Operating Characteristics (continued)
(Typical Operating Circuit, V
= SHDN = +3.0V, P
= -25dBm, P = -5dBm, T = +25°C, unless otherwise noted.)
RFIN LO A
CC
MAX2680
SHUTDOWN SUPPLY
CURRENT vs. SUPPLY VOLTAGE
MAX2682
SHUTDOWN SUPPLY
CURRENT vs. SUPPLY VOLTAGE
MAX2681
SHUTDOWN SUPPLY
CURRENT vs. SUPPLY VOLTAGE
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
0.10
SHDN = GND
SHDN = GND
SHDN = GND
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
T
= +85°C
A
T = +85°C
A
T
= +85°C
A
T
= +25°C
T
= +25°C
A
T
= +25°C
A
A
T
= -40°C
A
T
= -40°C
A
T
= -40°C
A
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
MAX2681
MAX2682
MAX2680
CONVERSION POWER GAIN vs. LO POWER
CONVERSION POWER GAIN vs. LO POWER
CONVERSION POWER GAIN vs. LO POWER
16
14
16
14
15
13
f
RF
= 900MHz
f
= 900MHz
f
RF
= 900MHz
RF
12
10
8
12
10
8
11
9
f
= 1950MHz
RF
f
= 1950MHz
RF
f
= 1950MHz
f
= 2450MHz
RF
RF
7
f
= 2450MHz
f
RF
f
RF
= 2450MHz
6
6
5
f
RF
f
f
f
f
IF
f
f
LO
f
IF
LO
IF
4
2
0
RF
LO
4
2
0
3
1
RF
900MHz 970MHz 70MHz
1950MHz 1880MHz 70MHz
2450MHz 2210MHz 240MHz
900MHz 970MHz 70MHz
1950MHz 1880MHz 70MHz
2450MHz 2210MHz 240MHz
900MHz 970MHz 70MHz
1950MHz
1880MHz 70MHz
2450MHz 2210MHz 240MHz
-1
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8 -6 -4 -2
0
LO POWER (dBm)
LO POWER (dBm)
LO POWER (dBm)
MAX2680
MAX2681
MAX2682
CONVERSION POWER GAIN vs. TEMPERATURE
CONVERSION POWER GAIN vs. TEMPERATURE
CONVERSION POWER GAIN vs. TEMPERATURE
16
16
17
f
RF
= 900MHz
f
= 900MHz
RF
14
14
15
f
RF
= 900MHz
12
10
8
12
10
8
13
11
9
f
= 1950MHz
RF
f
RF
= 1950MHz
f
RF
= 1950MHz
f
RF
= 2450MHz
f
RF
= 2450MHz
6
6
7
f
RF
= 2450MHz
f
f
f
IF
RF
LO
4
2
0
4
2
0
5
3
1
900MHz 970MHz 70MHz
1950MHz 1880MHz 70MHz
2450MHz 2210MHz 240MHz
60
-40 -20
0
20
40
60
80 100
-40 -20
0
20
40
80 100
-40 -20
0
20
40
60
80 100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Typical Operating Characteristics (continued)
(Typical Operating Circuit, V
= SHDN = +3.0V, P
= -25dBm, P = -5dBm, T = +25°C, unless otherwise noted.)
RFIN LO A
CC
MAX2680
INPUT IP3 vs. LO POWER
MAX2681
INPUT IP3 vs. LO POWER
MAX2682
INPUT IP3 vs. LO POWER
-5
2
7
f
f
f
= 1950MHz, 1951MHz
= 1880MHz
RF
LO
f
f
f
= 1950MHz, 1951MHz
= 1880MHz
RF
LO
6
5
4
3
2
1
0
-6
-7
1
0
= 70MHz
IF
P
= 70MHz
IF
P
= -25dBm PER TONE
RFIN
= -25dBm PER TONE
RFIN
-8
-1
-2
-3
f
f
f
= 1950MHz, 1951MHz
= 1880MHz
RF
LO
-9
= 70MHz
IF
P
= -25dBm PER TONE
RFIN
-10
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8
-6
-4
-2
0
LO POWER (dBm)
LO POWER (dBm)
LO POWER (dBm)
MAX2680
NOISE FIGURE vs. LO POWER
MAX2682
NOISE FIGURE vs. LO POWER
MAX2681
NOISE FIGURE vs. LO POWER
16
14
25
20
f
f
f
IF
RF
LO
18
16
14
12
10
8
900MHz 970MHz 70MHz
1950MHz
f
= 2450MHz
= 1950MHz
2020MHz 70MHz
2450MHz 2210MHz 70MHz
20
15
10
5
RF
12
10
8
f
f
= 2450MHz
= 1950MHz
RF
f
RF
RF
f
= 2450MHz
= 1950MHz
RF
f
= 900MHz
f
RF
RF
f
= 900MHz
6
RF
6
f
= 900MHz
RF
f
f
f
IF
RF
LO
f
f
f
IF
4
RF
LO
900MHz 970MHz 70MHz
1950MHz 2020MHz 70MHz
2450MHz 2210MHz 70MHz
4
900MHz 970MHz 70MHz
1950MHz 2020MHz 70MHz
2450MHz 2210MHz 70MHz
2
2
0
0
0
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8
-6
-4
-2
0
-14 -12 -10
-8
-6
-4
-2
0
0
LO POWER (dBm)
LO POWER (dBm)
LO POWER (dBm)
MAX2680
MAX2681
MAX2682
RF PORT IMPEDANCE vs. RF FREQUENCY
RF PORT IMPEDANCE vs. RF FREQUENCY
RF PORT IMPEDANCE vs. RF FREQUENCY
MAX2680/1/2-19
MAX2680/1/2-20
MAX2680/1/2-21
0
300
300
0
300
IMAGINARY
IMAGINARY
IMAGINARY
-100
-200
-300
-400
-500
-600
-100
-200
-300
-400
-500
-600
250
200
150
100
50
250
200
150
100
50
-100
-200
-300
-400
-500
-600
250
200
150
100
50
REAL
REAL
REAL
f
= 970MHz
= -5dBm
f
= 970MHz
= -5dBm
LO
f
= 970MHz
LO
LO
P
P
LO
= -5dBm
0
0
0
0
500
1000
1500
2000
2500
0
500
1000
1500
2000
2500
0
500
1000
1500
2000
2500
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
6
_______________________________________________________________________________________
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Typical Operating Characteristics (continued)
(Typical Operating Circuit, V
= SHDN = +3.0V, P
= -25dBm, P = -5dBm, T = +25°C, unless otherwise noted.)
RFIN LO A
CC
MAX2680
MAX2681
IF PORT IMPEDANCE vs. IF FREQUENCY
MAX2682
IF PORT IMPEDANCE vs. IF FREQUENCY
IF PORT IMPEDANCE vs. IF FREQUENCY
MAX2680/1/2-22
MAX2680/1/2-23
MAX2680/1/2-24
0
0
1200
1200
0
800
f
= 970MHz
= -5dBm
f
= 970MHz
= -5dBm
LO
LO
f
= 970MHz
= -5dBm
LO
P
P
LO
P
LO
-50
700
600
LO
-100
-200
-300
-400
-500
-600
-100
-200
-300
-400
-500
-600
1000
800
600
400
200
0
1000
800
600
400
200
0
-100
-150
IMAGINARY
IMAGINARY
500
400
IMAGINARY
-200
-250
-300
-350
-400
300
200
REAL
REAL
REAL
100
0
0
100
200
0
200
300
400
500
0
100
200
300
400
500
0
100
200
300
400
500
IF FREQUENCY (MHz)
IF FREQUENCY (MHz)
IF FREQUENCY (MHz)
MAX2681
LO PORT RETURN LOSS
MAX2680
LO PORT RETURN LOSS
MAX2682
LO PORT RETURN LOSS
+10
+10
+5
+10
+5
+5
0
0
0
-5
-5
-5
-10
-15
-20
-25
-30
-35
-40
-10
-15
-20
-25
-30
-35
-40
-10
-15
-20
-25
-30
-35
-40
200
760
1320
1880
2440
3000
760
1320
1880
2440
3000
200
760
1320
1880
2440
3000
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
MAX2680
LO-to-IF AND LO-to-RF ISOLATION
MAX2682
LO-to-IF AND LO-to-RF ISOLATION
MAX2681
LO-to-IF AND LO-to-RF ISOLATION
35
30
25
20
15
10
5
35
30
40
35
30
25
LO-to-IF ISOLATION
LO-to-IF ISOLATION
LO-to-IF ISOLATION
25
20
15
10
LO-to-RF ISOLATION
LO-to-RF ISOLATION
20
15
LO-to-RF ISOLATION
10
5
0
0
500
1000
1500
2000
2500
0
500
1000
1500
2000
2500
0
500
1000
1500
2000
2500
LO FREQUENCY (MHz)
LO FREQUENCY (MHz)
LO FREQUENCY (MHz)
_______________________________________________________________________________________
7
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Typical Operating Characteristics (continued)
(Typical Operating Circuit, V
= SHDN = +3.0V, P
= -25dBm, P = -5dBm, T = +25°C, unless otherwise noted.)
RFIN LO A
CC
MAX2682
TURN-OFF/ON CHARACTERISTICS
MAX2680
TURN-OFF/ON CHARACTERISTICS
MAX2681
TURN-OFF/ON CHARACTERISTICS
SHDN
2V/div
SHDN
2V/div
SHDN
2V/div
IFOUT
50mV/
div
IFOUT
50mV/
div
IFOUT
50mV/
div
Z1 = 39pF
500ns/div
Z1 = 39pF
500ns/div
Z2 = 39pF
500ns/div
Pin Description
PIN
NAME
FUNCTION
Local-Oscillator Input. Apply a local-oscillator signal with an amplitude of -10dBm to 0 (50Ω source). AC-
1
2
3
LO
couple this pin to the oscillator with a DC-blocking capacitor. Nominal DC voltage is V
- 0.4V.
CC
GND
RFIN
Mixer Ground. Connect to the ground plane with a low-inductance connection.
Radio Frequency Input. AC-couple to this pin with a DC-blocking capacitor. Nominal DC voltage is 1.5V.
See Applications Information section for details on impedance matching.
Intermediate Frequency Output. Open-collector output requires an inductor to V . AC-couple to this pin
CC
with a DC-blocking capacitor. See Applications Information section for details on impedance matching.
4
5
6
IFOUT
Supply Voltage Input, +2.7V to +5.5V. Bypass with a capacitor to the ground plane. Capacitor value
depends upon desired operating frequency.
V
CC
Active-Low Shutdown. Drive low to disable all device functions and reduce the supply current to less than
SHDN
5µA. For normal operation, drive high or connect to V
.
CC
8
_______________________________________________________________________________________
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
IF Output
Detailed Description
The IF output frequency range extends from 10MHz to
500MHz. IFOUT is a high-impedance, open-collector
The MAX2680/MAX2681/MAX2682 are 400MHz to
2.5GHz, silicon-germanium, double-balanced down-
converter mixers. They are designed to provide opti-
mum linearity performance for a specified supply
current. They consist of a double-balanced Gilbert-cell
mixer with single-ended RF, LO, and IF port connec-
tions. An on-chip bias cell provides a low-power shut-
down feature. Consult the Selector Guide for device
features and comparison.
output that requires an external inductor to V
for
CC
proper biasing. For optimum performance, the IF port
requires an impedance-matching network. The configu-
ration and values for the matching network is depen-
dent upon the frequency and desired output
impedance. For assistance in choosing components for
optimal performance, refer to Tables 3 and 4 as well as
the IF Port Impedance vs. IF Frequency graph in the
Typical Operating Characteristics.
Applications Information
SHDN
Power-Supply and
Proper attention to voltage supply bypassing is essen-
tial for high-frequency RF circuit stability. Bypass V
Bypassing
Local-Oscillator (LO) Input
The LO input is a single-ended broadband port with a
typical input VSWR of better than 2.0:1 from 400MHz to
2.5GHz. The LO signal is mixed with the RF input sig-
nal, and the resulting downconverted output appears at
IFOUT. AC-couple LO with a capacitor. Drive the LO
port with a signal ranging from -10dBm to 0 (50Ω
source).
CC
with a 10µF capacitor in parallel with a 1000pF capaci-
tor. Use separate vias to the ground plane for each of
the bypass capacitors and minimize trace length to
reduce inductance. Use separate vias to the ground
plane for each ground pin. Use low-inductance ground
connections.
RF Input
The RF input frequency range is 400MHz to 2.5GHz.
The RF input requires an impedance-matching network
as well as a DC-blocking capacitor that can be part of
the matching network. Consult Tables 1 and 2, as well
as the RF Port Impedance vs. RF Frequency graph in
the Typical Operating Characteristics for information on
matching.
Decouple SHDN with a 1000pF capacitor to ground to
minimize noise on the internal bias cell. Use a series
resistor (typically 100Ω) to reduce coupling of high-fre-
quency signals into the SHDN pin.
Layout Issues
A well designed PC board is an essential part of an RF
circuit. For best performance, pay attention to power-
supply issues as well as to the layout of the RFIN and
IFOUT impedance-matching network.
Table 1. RFIN Port Impedance
FREQUENCY
PART
400MHz
179-j356
209-j332
206-j306
900MHz
54-j179
75-j188
78-j182
1950MHz
2450MHz
33-j73
MAX2680
MAX2681
MAX2682
32-j94
34-j108
34-j106
33-j86
29-j86
Table 2. RF Input Impedance-Matching Component Values
FREQUENCY
MAX2680
MAX2681
MAX2682
MATCHING
COMPONENTS
400
MHz
900
MHz
1950
MHz
2450
MHz
400
MHz
900
1950
MHz
2450
MHz
400
MHz
900
1950
MHz
2450
MHz
MHz
270pF
18nH
Open
MHz
1.5pF
270pF
10nH
Z1
Z2
Z3
86nH
270pF
Open
270pF 1.5pF
Short
68nH
1.5pF
Short
68nH
Short
Short
22nH
Open
270pF 270pF 270pF
1.8nH 1.8nH 0.5pF
270pF 270pF 270pF
1.8nH 2.2nH 0.5pF
270pF 270pF
2.2nH 1.2nH
Note: Z1, Z2, and Z3 are found in the Typical Operating Circuit.
_______________________________________________________________________________________
9
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Power-Supply Layout
Table 3. IFOUT Port Impedance
To minimize coupling between different sections of the
IC, the ideal power-supply layout is a star configuration
FREQUENCY
PART
with a large decoupling capacitor at a central V
CC
45MHz
960-j372
934-j373
670-j216
70MHz
240MHz
186-j397
161-j375
175-j296
node. The V
traces branch out from this central
CC
node, each going to a separate V node on the PC
MAX2680
MAX2681
MAX2682
803-j785
746-j526
578-j299
CC
board. At the end of each trace is a bypass capacitor
that has low ESR at the RF frequency of operation. This
arrangement provides local decoupling at the V
pin.
CC
At high frequencies, any signal leaking out of one sup-
ply pin sees a relatively high impedance (formed by the
V
CC
trace inductance) to the central V
node, and an
CC
Table 4. IF Output Impedance-Matching
Components
even higher impedance to any other supply pin, as well
as a low impedance to ground through the bypass
capacitor.
FREQUENCY
MATCHING
Impedance-Matching Network Layout
The RFIN and IFOUT impedance-matching networks are
very sensitive to layout-related parasitics. To minimize
parasitic inductance, keep all traces short and place
components as close as possible to the chip. To mini-
mize parasitic capacitance, use cutouts in the ground
plane (and any other plane) below the matching network
components. However, avoid cutouts that are larger
than necessary since they act as aperture antennas.
COMPONENT
45MHz
390nH
39pF
70MHz
330nH
15pF
240MHz
82nH
3pF
L1
C2
R1
250Ω
Open
Open
Typical Operating Circuit
C1
LO
INPUT
1
2
6
SHUTDOWN
CONTROL
SHDN
LO
C3
MAX2680
MAX2681
MAX2682
5
4
V
CC
V
CC
GND
+2.7V TO +5.5V
C4
1000pF
C5
10µF
R1
L1
Z
2
Z
1
RF
INPUT
IF
OUTPUT
3
RFIN
IFOUT
C2
Z
3
THE VALUES OF MATCHING COMPONENTS C2, L1, R1, Z1, Z2, AND Z3 DEPEND ON THE IF AND RF FREQUENCY AND DOWNCONVERTER. SEE TABLES 2 AND 4.
10 ______________________________________________________________________________________
400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, SOT-23, 6L
1
21-0058
F
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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