DATASHEET

HFA3600
®
NO RE
U CT
NT
PROD
E
T
E
CEME
L
OBSO DED REPLA
Data Sheet
EN
COMM
August 2002
FN3655.5
Low-Noise Amplifier/Mixer
Features
The HFA3600 is a silicon Low-Noise Amplifier with high
performance characteristics allowing the design of very
sensitive, wide dynamic-range 900MHz receivers with
minimal external components.
• LNA
- Low Noise Figure . . . . . . . . . . . . . . . . 2.3dB at 900MHz
- High Power Gain . . . . . . . . . . . . . . . 12.8dB at 900MHz
- High Intercept . . . . . . . . . . . . . . . . +12.8dBm at Output
The LNA, Mixer RF, and LO inputs are internally matched to
50Ω. The Mixer IF output is open collector allowing flexibility
in choosing the IF output impedance, with 1000Ω operation
fully characterized. The mixer performance is optimized for
low LO drive (-3dBm) applications.
• MIXER
- Low Noise Figure . . . . . . . . . . . . . . . 12.1dB at 900MHz
- High Power Gain . . . . . . . . . . . . . . . . 7.0dB at 900MHz
- High Intercept . . . . . . . . . . . . . . . . . . +3.2dBm at Output
- Low LO Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . - 3dBm
Power consumption is kept to a minimum, making the device
ideal for battery-powered hand-held communication
equipment. An integrated power-down feature maximizes
battery life and eliminates the need for external shut down
circuitry. Although fully characterized under 5V single supply,
the HFA3600 is operable down to 4V with slight performance
differences.
The HFA3600 is part of a complete solution including
application circuit schematics, S-parameters, noise figure,
third-order intercept characterization data and PC board
artwork. Evaluation boards are also available through local
Intersil Sales offices.
HFA3600IB
• Portable Cellular Telephone (AMPS, IS-54, GSM, JDC)
• UHF and Mobile Radio Receiver
TEMP.
RANGE (oC)
-40 to 85
Applications
• Wireless Data Com. (ISM, Narrowband PCS)
Part Number Information
PART
NUMBER
• LNA + MIXER
- Low Noise Figure . . . . . . . . . . . . . . . 3.97dB at 900MHz
- High Power Gain . . . . . . . . . . . . . . . 19.8dB at 900MHz
- High Intercept . . . . . . . . . . . . . . . . . . .-16.7dBm at Input
- Low Operating Power . . . . . . . . . . . . . . . . . . 5V/11.3mA
- Low Shutdown Power . . . . . . . . . . . . . . . . . . . 5V/250µA
- Small Package: 14 Lead SOIC (Plastic, Small Outline
Package, 150 Mil Width, 50 Mil Lead Spacing)
PACKAGE
14 Ld SOIC
PKG. NO.
M14.15
• 900MHz Digital Cordless Telephone (CT-2, ISM)
• Wireless Telemetry
Block Diagram
Pinout
HFA3600 (SOIC)
TOP VIEW
14 MIXER VCC
LNA VCC 1
GND 2
14 MIXER VCC
LNA VCC 1
GND 2
13 IF OUT
LNA IN 3
12 GND
GND 4
11 RF IN
GND 5
10 GND
LO BYPASS 6
13 IF OUT
LNA IN 3
IF
GND 4
GND 5
RF
LO
LNA
LO BYPASS 6
LO IN 7
12 GND
11 RF IN
10 GND
9 LNA OUT
BIAS
8 POWER DOWN
9 LNA OUT
8 POWER DOWN
LO IN 7
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002. All Rights Reserved
HFA3600
Absolute Maximum Ratings
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0V
Voltage on Any Other Pin. . . . . . . . . . . . . . . . . . . . -0.3 to VCC+0.3V
VCC to VCC Decouple . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +0.3V
Any GND to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +0.3V
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . -40oC ≤ TA ≤ 85oC
Supply Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 to 5.5V
θJA (oC/W)
Thermal Resistance (Typical, Note 1)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
125
Maximum Package Power Dissipation at 25oC . . . . . . . . . . . . . . 1W
Maximum Junction Temperature (Plastic Package) . . . . . . . .150oC
Maximum Storage Temperature Range . . . . . . .-65oC ≤ TA ≤ 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC
(Lead Tips Only)
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
DC Electrical Specifications
SYMBOL
ICC
TEMP
(oC)
MIN
TYP
MAX
UNITS
Normal PD = 2V
A
25
-
11.3
12.5
mA
Shutdown PD = 0.8V
A
25
-
250
375
µA
PARAMETER
CONDITION
Total Supply Current at 5V
ALL GRADES
TEST
LEVEL
VIH
Shutdown Logic High
Normal Mode
A
25
2
-
VCC
V
VIL
Shutdown Logic Low
Shutdown Mode
A
25
-0.3
-
0.8
V
IIL
Shutdown Input Current
PD = 0.4V
A
25
-200
-150
-100
µA
IIH
Shutdown Input Current
PD = 2.4V
A
25
-45
-24
-3
µA
LNA Input DC Level
Normal Mode
A
25
-
0.79
-
V
Shutdown Mode
A
25
-
0.0
-
V
Normal Mode
A
25
-
4.9
-
V
Shutdown Mode
A
25
-
5.0
-
V
Normal Mode
A
25
-
0.79
-
V
Shutdown Mode
A
25
-
0.0
-
V
Normal Mode
A
25
-
2.1
-
V
Shutdown Mode
A
25
-
0.0
-
V
B
25
-
10
-
µs
MAX
UNITS
VLNA-IN
VLNA-OUT
VMX-RF
VMX-LO
tOFF , ON
LNA Output DC Level
Mixer RFIN DC Level
Mixer LOIN DC Level
Shutdown On-Off-On Time
AC Electrical Specifications
All Characterization Results have been Obtained with the Use of a
Standard Evaluation Board.
SYMBOL
PARAMETER
TEST
LEVEL
TEMP
(oC)
ALL GRADES
MIN
TYP
LNA (VCC = +5V, TA = 25oC, Test Figure 1 and f = 900MHz Unless Otherwise Noted In Characterization Curves)
S21LNA
LNA Gain
B
25
11.8
12.8
13.8
dB
S12LNA
LNA Reverse Isolation
B
25
-
23
-
dB
S11LNA
LNA Input Return Loss
B
25
6.0
7.3
-
dB
S22LNA
LNA Output Return Loss
B
25
10.0
13.0
-
dB
LNA Output 1-dB Gain Compression Point
B
25
-
-2.0
-
dBm
IP3LNA
LNA Output 3rd-Order Intercept
B
25
+11.2
+12.8
-
dBm
NFLNA
LNA Noise Figure
B
25
-
2.30
2.60
dB
P-1dBLNA
2
HFA3600
AC Electrical Specifications
All Characterization Results have been Obtained with the Use of a
Standard Evaluation Board. (Continued)
SYMBOL
TEST
LEVEL
PARAMETER
TEMP
(oC)
ALL GRADES
MIN
TYP
MAX
UNITS
MIXER (VCC = 5V, TA = 25oC, fLO = 825MHz at -3dBm, fRF = 900MHz, fIF = 75MHz and Test Figure 1, Unless Otherwise Noted)
PGC
MIXER Power Conversion Gain
B
25
5.9
7.0
8.1
dB
S11RF
MIXER RF Input Return Loss
B
25
8.0
11.0
-
-
S11LO
MIXER LO Input Return Loss
B
25
18.0
26
-
dB
NFMIXER
MIXER SSB Noise Figure
B
25
-
12.1
13.9
dB
P-1dBMIX
MIXER Output 1-dB Gain Compression
B
25
-
-7.5
-
dBm
MIXER Output 3rd-Order Intercept
B
25
+1.0
+3.2
-
dBm
MIXER IF Output Capacitance
B
25
-
2.3
-
pF
GRF-IF
MIXER RF-IF Isolation
(Includes Matching Network)
B
25
-
25
-
dB
GLO-IF
MIXER LO-IF Isolation
(Includes Matching Network)
B
25
-
16
-
dB
GLO-RF
MIXER LO-RF Isolation
B
25
16
21
-
dB
Mixer LO-LNAIN Isolation
B
25
42
50
-
dB
LNAOUT-Mixer RFIN Isolation
B
25
35
40
-
dB
IP3MIX
COUTMIX
GLO-LNAIN
GLNAOUT -RF
(LNA + MIXER) VCC = 5V, TA = 25oC, fLO = 825MHz at -3dBm, fRF = 900MHz, fIF = 75MHz and Idealized Lossless External Filters
CPGC
Power Conversion Gain
B
25
-
19.8
-
dB
CNF
Noise Figure
B
25
-
3.97
-
dB
CIP3
Input 3rd-Order Intercept
B
25
-
-16.7
-
dBm
NOTE: Test Level: A. Production Tested. B. Guaranteed Limit or Typical Based on Characterization.
Test Circuits
2 x 0.01µF
4.7µF
1
LNA IN
1000pF
1000pF
2
13
3
12
4
11
5
10
6
9
7
LO IN
1000pF
VCC (+5V)
14
8
10µH
1kΩ
1nF
RF IN
1000pF
LNA OUT
1000pF
PD(TTL)
FIGURE 1. EVALUATION TEST CIRCUIT
3
390nH
3-10pF
IF OUT
75MHz
50Ω
HFA3600
Test Circuits
(Continued)
2 x 0.01µF
4.7µF
DUPLEXER
0.01µF
LNA IN
1000pF
1000pF
FROM TRANSMITTER
LO IN
1
VCC
14
2
13
3
12
4
11
5
10
6
9
7
8
1000pF
10µH
1kΩ
1nF
1000pF
IF FILTER (50Ω)
390nH
IF OUT
3-10pF
IF AMPLIFIER
IMAGE FILTER (50Ω)
1000pF
PD(TTL)
FIGURE 2. TYPICAL APPLICATION CIRCUIT
TABLE 1. TYPICAL CELLULAR FRONT-END CASCADED PERFORMANCE
DUPLEXER
LNA
IMAGE
FILTER
MIXER
IF FILTER
IF AMP
UNITS
Noise Figure
3.0
2.3
3.0
12.1
8.0
3.0
dB
Gain
-3.0
12.8
-3.0
7.0
-8.0
20.0
dB
100.0
12.8
100.0
3.2
OUTPUT IP3
Cascaded Noise Figure = 8.55dB
Not Applicable (Note)
Cascaded Gain = 25.8dB
dBm
Input IP3 = -10.8dBm
NOTE: Cascaded results are using 100.0dBm for IP3.
Supply Characteristics
11.0
300
TICC
TICC OFF
10.0
250
200
9.0
350
11.7
300
11.5
11.3
250
T ICC OFF
TICC
200
11.1
4.5
4.7
4.9
5.1
5.3
SUPPLY VOLTAGE
FIGURE 3. TOTAL ICC vs SUPPLY VOLTAGE
4
5.5
- 40
- 20
0
20
40
60
TEMPERATURE (oC)
FIGURE 4. TOTAL ICC vs TEMPERATURE
80
150
TOTAL SHUTDOWN ICC (mA)
350
TOTAL ICC (mA)
TOTAL ICC (mA)
12.0
TOTAL SHUTDOWN ICC (mA)
400
11.9
HFA3600
LNA Characteristics
20
20
2dB/DIV
2dB/DIV
25
5.5V
MAGNITUDE (dB)
MAGNITUDE (dB)
5.0V
4.5V
0
800
900
85
0
800
1000
900
FREQUENCY (MHz)
FREQUENCY (MHz)
FIGURE 5. LNA S21 vs FREQUENCY AND VCC
-40
1000
FIGURE 6. LNA S21 vs FREQUENCY AND TEMPERATURE
0
0
2dB/DIV
5dB/DIV
85
25
MAGNITUDE (dB)
MAGNITUDE (dB)
25
-40
-40
-50
-20
800
900
FREQUENCY (MHz)
800
1000
FIGURE 7. LNA S11 vs FREQUENCY AND TEMPERATURE
85
900
FREQUENCY (MHz)
1000
FIGURE 8. LNA S12 vs FREQUENCY AND TEMPERATURE
0.00
0
2dB/DIV
MAGNITUDE (dB)
-1.00
85
P1dB (dBm)
25
900
FREQUENCY (MHz)
1000
FIGURE 9. LNA S22 vs FREQUENCY AND TEMPERATURE
5
-3.00
-4.00
-40
-20
800
-2.00
-5.00
800
900
FREQUENCY (MHz)
1000
FIGURE 10. LNA OUTPUT 1dB COMPRESSION vs FREQUENCY
HFA3600
LNA Characteristics
(Continued)
1.0
2.318
f = 900MHz
0.0
-1.0
NF (dB)
PO 1dB (dBm)
2.309
-2.0
2.300
2.291
-3.0
2.282
-4.0
- 40
- 20
20
0
40
60
80
800
900
TEMPERATURE (oC)
1000
FREQUENCY (MHz)
FIGURE 11. LNA OUTPUT 1DB COMPRESSION vs
TEMPERATURE
FIGURE 12. LNA 50Ω NF vs FREQUENCY
15.0
2.9
f1 = 900.5MHz
f2 = 899.5MHz
IP3 OUT (dBm)
14.0
NF (dB)
2.7
2.5
13.0
12.0
2.3
11.0
2.1
- 40
- 20
20
0
40
60
80
10.0
800
850
TEMPERATURE (oC)
900
950
1000
FREQUENCY (MHz)
FIGURE 13. LNA 50Ω NF vs TEMPERATURE
FIGURE 14. LNA OUTPUT IP3 vs FREQUENCY
13.5
f1 = 900.5MHz
f2 = 899.5MHz
FREQ
IP3OUT (dBm)
13.0
12.5
12.0
11.5
11.0
- 40
- 20
20
0
40
60
S11
S21
DEG
S22
dB
DEG
MHz
dB
DEG
dB
800
-6.7
153
13.7
11.4 -11.9 -170 -23.8
-41
850
-7.0
143
13.3
1.5
-12.0
171
-23.1
-48
900
-7.3
133
12.8
-7.7
-13.0
155
-23.0
-56
950
-7.4
123
12.6
-18
-12.0
137
-23.1
-65
1000
-7.6
113
12.2
-27
-11.8
120
-22.8
-70
80
TEMPERATURE (oC)
FIGURE 16. LNA S-PARAMETERS
FIGURE 15. LNA OUTPUT IP3 vs TEMPERATURE
6
S12
dB
DEG
HFA3600
Mixer Characteristics
9.0
POWER GAIN (dB)
POWER GAIN (dB)
8.0
7.0
6.0
5.0
8.0
7.0
6.0
-6
-2
-4
0
+2
- 40
+4
- 20
FIGURE 17. MIXER PG vs LO DRIVE
80
13.0
NOISE FIGURE (dB)
NOISE FIGURE (dB)
60
FIGURE 18. MIXER PG vs TEMPERATURE
14.0
13.0
12.0
12.0
11.0
10.0
11.0
-6
-4
-2
0
+2
- 40
+4
- 20
0
20
40
60
80
TEMPERATURE (oC)
LO DRIVE (dBm)
FIGURE 19. MIXER NF vs LO DRIVE
FIGURE 20. MIXER NF vs TEMPERATURE
f1 RF = 900.5MHz
f2 RF = 899.5MHz
5.0
OUTPUT IP3 (dBm)
15.0
NOISE FIGURE (dB)
40
20
0
TEMPERATURE (oC)
LO DRIVE (dBm)
14.0
13.0
12.0
11.0
4.0
3.0
2.0
1.0
50
75
100
125
FREQUENCY (MHz)
FIGURE 21. MIXER NF vs IF FREQUENCY, RF = 900MHz,
FLO < FRF
7
150
-6
-4
-2
0
+2
LO DRIVE (dBm)
FIGURE 22. MIXER OUTPUT IP3 vs LO DRIVE
+4
HFA3600
Mixer Characteristics
(Continued)
- 6.0
- 6.0
P- 1dB (dBm)
- 5.0
P- 1dB (dBm)
- 5.0
- 7.0
- 7.0
- 8.0
- 8.0
- 9.0
- 9.0
- 10.0
-6
-4
-2
0
LO DRIVE (dBm)
+2
+4
- 10.0
- 40
- 20
0
20
40
60
80
TEMPERATURE (oC)
FIGURE 23. MIXER 1dB COMPRESSION vs LO DRIVE
FIGURE 24. MIXER 1dB COMPRESSION vs TEMPERATURE
4.0
OUTPUT IP3 (dBm)
OUTPUT IP3 (dBm)
4.0
3.0
2.0
3.0
2.0
1.0
1.0
- 40
- 20
0
20
40
60
80
FIGURE 26. MIXER OUTPUT IP3 vs RF FREQUENCY
0
0
2dB/DIV
5dB/DIV
-40
MAGNITUDE (dB)
MAGNITUDE (dB)
1000
FREQUENCY (MHz)
FIGURE 25. MIXER OUTPUT IP3 vs TEMPERATURE
- 50
700
900
800
TEMPERATURE (oC)
25
85
85
-40
25
- 20
850
FREQUENCY (MHz)
FIGURE 27. MIXER LO S11 vs FREQUENCY AND
TEMPERATURE
8
1000
700
850
FREQUENCY (MHz)
FIGURE 28. MIXER RF S11 vs FREQUENCY AND
TEMPERATURE
1000
HFA3600
Isolation Characteristics
0
0
-100
700
25
10dB/DIV
85
MAGNITUDE (dB)
MAGNITUDE (dB)
10dB/DIV
-40
850
FREQUENCY (MHz)
25
85
-100
700
1000
FIGURE 29. LNA OUT TO MIXER RF ISOLATION vs
FREQUENCY AND TEMPERATURE
-40
850
FREQUENCY (MHz)
FIGURE 30. MIXER LO IN TO LNA IN ISOLATION vs
FREQUENCY AND TEMPERATURE
0
5dB/DIV
MAGNITUDE (dB)
25
-40
85
-40
700
850
1000
FREQUENCY (MHz)
FIGURE 31. MIXER LO TO RF ISOLATION vs FREQUENCY AND TEMPERATURE
9
1000
HFA3600
LNA Noise and Gain Characteristics
4.0
0.5
MINIMUM NF (dB)
1
2
3
3.0
10.0
2.0
NF
5.0
5
1.0
10
900MHz
100MHz
1
2
600
5
900
FREQUENCY (MHz)
FIGURE 32. LNA GAMMA OPTIMUM vs FREQUENCY
FIGURE 33. MINIMUM NOISE FIGURE AND ASSOCIATED
GAIN vs FREQUENCY
1
0.5
2
3
2.5dB
2.3dB
10
2.2dB
0
1
11.5dB
2
5
-10
13.5dB
-5
14dB
-3
-0.5
-2
-1
FIGURE 34. LNA NOISE AND GAIN CIRCLES AT 900MHz
10
0
1200
ASSOCIATED GAIN (dB)
15.0
GAIN
HFA3600
Evaluation Board Layout Information
Component List:
C1, C6 Cap, fixed.01µF
R1 Res, fixed 1kΩ
C2 Cap, fixed Tantalum. 4.7µF
L1 Ind., fixed 10µH
C8 Cap, var. 3pF to 10pF
L2 Ind., fixed 390nH
Cr1 Diode DL4001
C3, C4, C5, C7, C10, C11 Cap, fixed 1nF
EVALUATION BOARD LAYOUT SCALE X1
TOP VIEW
EVALUATION BOARD COMPONENT PLACEMENT
GND
VCC
IF OUT
CR1
L2
C1 C2
LNA IN
L1
C7
C8
C6 R1
C6
C3
C4
C5
RF IN
C10
8
C11
LNA OUT
LO IN
PD
NOTE: See Evaluation Board testing information.
11
HFA3600
Pin Description
Characterization Information
LNA VCC
The curves and data depicted in the Specifications Section
are the result of the design characterization performed by
the use of a standard evaluation board and a statistically
significant sample procedure which reflects the INTERSIL
UHF-1 process variation.
Supply voltage for the Low Noise amplifier.
LNA In
LNA input. Requires AC coupling. Minimum coupling
capacitor value of 100pF is suggested. This input is
optimized for 50W match in the 800MHz to 1000MHz range.
LO Bypass
Mixer LO Bypass. Capacitor required to assure a good AC
ground. Placement is critical. The bypass capacitance
should be located close to the device with low ground
impedance. Minimum coupling capacitor value of 100pF is
suggested.
LO In
Local oscillator input. Requires AC coupling. Input is
optimized for 50W match in the 700MHz to 1000MHz range.
Minimum coupling capacitor value of 100pF is suggested.
Power Down
Power down control with internal pull up. A low TTL or
CMOS level disables the bias network, shutting down both
the LNA and the MIXER within 10ms. The internal pull up is
provided for users that do not require the power down
feature. Provided for Time Division Multiplex Systems and/or
power savings.
LNA Out
Output of the LNA. Requires AC coupling. This output has
been optimized for 50W match in the 800MHz to 1000MHz
range. Minimum coupling capacitor value of 100pF is
suggested.
RF In
RF input to the MIXER. Requires AC coupling. Input
optimized for 50W match in the 800MHz to 1000MHz range.
Minimum coupling capacitor value of 100pF is suggested.
IF Out
Open collector output of the MIXER. Output capacitance is
2.3pF typical. The use of a RF choke maximizes the voltage
output swing but is not mandatory. An output resistance
controls the conversion gain as well as IP3 within the useful
range of 300W to 1500W. It also affects the output
impedance required for the next filter stage and facilitates
any output matching network design requirements.
Conversion gain is reduced upon use of low value resistors.
Mixer VCC
Supply voltage for the MIXER and the Bias Network.
The use of standard RF techniques have been employed
throughout the characterization process with special
emphasis on noise figures, gains and LO level
performances.
Special attention has been given to the Local oscillator
signal purity and integrity throughout the low and high
frequency spectrum.
The use of low Excess Noise Ratio (ENR) noise sources
have been employed to guarantee a good 50Ω noise source
output impedance during the LNA noise measurements.
The use of attenuators for most of the setups have assured
output impedances of signals closer to 50W when the use of
power splitters and filters with poor return loss were
necessary.
50Ω environment measurements have been carried
throughout the characterization process including the IF
output from the MIXER.
Device Description
The HFA3600 is fabricated in the INTERSIL UHF-1 Bonded
wafer, Silicon on Insulator process. ft characteristics of
10GHz and Power bandwidth product of 6GHz together with
the robustness of the SOI process ensure high reliability for
high frequency volume production. The process features low
parasitic capacitances and very low leakages.
LNA
The LNA uses a single stage topology with a collector spiral
inductor to improve the stability at lower frequencies and to
optimize the power gain in the 900MHz range. Typical noise
figure of 2.3dB, gain of 12.8dB and third order output
intercept point of +12.8dBm are the main features. Bias
currents are laser trimmed for optimum performances and
for tight distribution among production lots. Under a 50Ω
environment, the LNA input return loss is 7.3dB and the
output return loss is 13dB. Characteristics of the gamma
optimum, which is shown in the specifications section,
suggests that the optimum source impedance driving the
LNA for minimum noise figure is located close to 50Ω. The
trade-off between gain and noise figures at 900MHz are
shown in the gain and noise circles representation of the
specification section.
Mixer
The HFA3600 Mixer uses a single balanced topology. This
topology features an open collector with an output capacitance
in the order of 2.3pF. Bias settings are also laser trimmed for
12
HFA3600
optimum performance and tight distribution among production
lots. The open collector output permits direct interface to
moderate impedance IF filters as well as 50W input filters after
a simple “L” impedance matching network. A collector resistor
of 1K has been used throughout the characterization together
with an impedance matching network for 50W load
measurements. With a low -3dBm LO level, a typical SSB noise
figure of 12.1dB, conversion gain of 7.0dB and a third order
output intercept point of +3.2dBm are the main features. The
LO input return loss is typically of 26dBm and the RF input
return loss has a typical value of 11dB.
Bias Network and Power Down
The Bias Network is responsible for the accurate setting of
both LNA and MIXER operating currents. The LNA operating
current is accurately set to 5mA while the MIXER is set to
4mA. Laser trimming procedures and a temperature
independent performance of the bias cell, assure the worst
case operating current variation of the LNA and MIXER of
1% over the operating temperature range.
The Bias network is powered by the Mixer VCC pin and has
a built in feature of disabling both the LNA and the MIXER
stages. The cell can be powered up and down within 10ms.
Power down total current consumption is in the order of
250mA. The simplified schematic of the power down input
circuit is shown below.
MIXER VCC
15K
PD
10K
100K
FIGURE 35. ENABLE PIN INPUT CIRCUIT
Low Voltage Operation
Low voltage operation is possible with the HFA3600. The
HFA3600 has been characterized with VCC of 4V and only
moderate degradations have been observed compared to
the AC performance at a VCC of 5V. The LNA gain shows a
0.8dB decrease and a 1.5dB degradation in the output
intercept point with no measurable impact on noise figure.
The MIXER behavior at 4V can be summarized with a
degradation of conversion gain and output intercept point of
0.8dB and a slight improvement in noise figure of 0.6dB.
13
Other relevant 4V performance characteristics include:
• Total ICC: typical drop of 2.2mA
• LNA Input Return Loss: degraded by 0.6dB
• LNA Reverse Isolation: degraded by 1dB
• LNA Output Return Loss: degraded by 1dB
• RF to IF Isolation: no change
• LOin to LNAin Isolation: improvement by 2dB
• LNAOUT to Mixer RFIN Isolation: improvement by
0.2dB
• Mixer LO to RF Isolation: no change
• Mixer LO to IF Isolation: degrades by 0.5dB
• Mixer RF input Return Loss: degrades by 1dB
• Mixer LO Input Return Loss: degrades by 0.3dB at
800MHz and 1dB at 700MHz
Layout Considerations
The HFA3600 evaluation board layout has been carefully
designed for an accurate RF characterization of the device.
50Ω microstrip lines have been provided to permit the
connection of the LNA and MIXER independently and
facilitate the user interface for testing. Top ground planes
were used to assure adequate isolation between critical
traces.
The HA3600 package pinout has been laid out for best
isolation and overall device performance which also permits
the placement and connection of ground planes at pins 2, 4,
5, 10 and 12. Pin 4 and Pin 5 assure a low impedance
ground return for the LNA and also helps the isolation
between the LNA input and the LO input. The LNA output pin
is isolated from the RF input port with a good ground
connection between the top and back ground planes
terminated at pin 10. A series of plated through holes
resembling a stitch pattern are sufficient and important for
the LNA-OUT and RF-IN ports isolation, so the designer can
rely on the full characteristics of rejection of the image filter.
Similar isolation pattern is drawn and terminated in pin 12 to
isolate the RF-IN from the IF-OUT port.
A ground pad has been laid down beneath the package with a
series of plated through holes to minimize the inductance to
the ground plane and improve the device gain characteristics.
All device grounds must be connected as close to the
package as possible and the same applies to both VCC
inputs and all VCC bypass capacitors. A small 4.7µF
tantalum capacitor at the VCC line will prevent supply
coupling to the bias network if the device is subjected to
strong low frequency interference signals.
A protection diode has been added to the demonstration
board for extra protection and is not needed in an actual
application.
HFA3600
Evaluation Board Testing Information
Cascaded Evaluation
The following paragraphs contain information related to the
evaluation of the HFA3600 LNA/Mixer noise figure and
common errors encountered during individual and cascaded
performance verification. A simple cascaded arrangement
using a simple Π network as an intermediate filter is
included.
The cascaded evaluation of the HFA3600 demo-board must
be carried out with a filter network between the LNA and the
mixer when noise figure or sensitivity measurements are
made. Any bandpass/highpass implementation must be
utilized to function as either an image or noise rejection filter.
Poor isolation from the RF input to the IF output results in
direct amplification (not only frequency translation) of
undesired signals at the RF input port. For example, any
noise within the IF passband generated by a previous active
system block (LNA or any other amplifier) is directly
transferred and amplified to the IF output. This lack of
isolation can considerably degrade the translated signal to
noise ratio of the IF output. An image filter placed before the
mixer RF input port can solve the problem. Image filters are
normally implemented as narrow bandpass filters which are
tuned to pass only the desired (LO+IF) or (LO-IF) frequency
of interest. Consequently, the role of rejecting noise at
frequencies within the IF passband is accomplished.
Poor isolation from the LO input to IF output can also slightly
degrade the translated signal to noise ratio of the IF output in
two distinct ways: the noise generated by the local oscillator
at the IF frequency band is directly coupled to the IF port,
and the noise at the RF and image RF passbands (LO SSB
noise) gets translated to the IF passband and appears in the
IF output. To overcome these problems, the use of a band
pass filter is recommended between the local oscillator and
the LO input for optimization of the mixer noise figure.
The lack of isolation from the LO input port back to the RF
input port can cause constructive or destructive interference
at the RF port which can affect noise and conversion
(translation) gain performance.
LNA
SMA
1000pF
3.5pF
10nH
SMA 1000pF
RF
IF
LO
10nH
Π COMPONENTS SHOWN ARE FOR 900MHz RF
A “T” FILTER CAN ELIMINATE THE 1000pF COUPLING CAPACITORS
FIGURE 36. HFA3600 HIGH PASS FILTER IMPLEMENTATION
Tuning of the Π network, if necessary, is done by changing
the value of the 3.5pF capacitor. This low value of
capacitance may be dependent on the rider layout. The
value may be optimized for low insertion loss and, therefore,
for optimum cascaded noise figure.
Figure 37 and Tables 2 and 3 illustrate the overall
performance of the HFA3600 in a cascaded form at 915MHz
RF input and 75MHz IF frequency:
TABLE 2. SSB MEASUREMENT SET UP (BANDPASS
INPUT FILTER) (NOTES 1, 3)
NF
(dB)
GAIN
(dB)
COMMENTS
Saw, 3dB Loss
5.1
16.0
Gain reduced by the filter loss
Short/No Filter
14.4
N/A
NF degrades due to the IF
noise from the LNA
Π Filter, No Loss at
the RF Frequency
5.2
19.0
Note the increase in cascaded
gain
IMAGE FILTER
14
RFIN
Active single balanced mixers are low cost, low power
dissipation devices which require low local oscillator levels to
operate. As single balanced mixers lack high isolation from
the RF and LO input ports to the IF output and operate with
moderate feedthrough from the LO input to the RF input,
special precautions must be taken when evaluating these
devices with test set ups, specifically filtering, and cabling
hook ups. These constraints, although important during the
evaluation of the device, are not major issues in the design
of the overall system.
To remove the IF noise being generated or amplified by the
LNA, a low cost Π or “T” high pass filter can be utilized. This
simple high pass filter can be used for a cascaded noise
evaluation of the HFA3600. Although this implementation
does not remove the image signal nor the image noise being
generated by the LNA, this filter gives an overall cascaded
performance that closely approximates the results obtained
by calculation. The large contribution of the LNA gain at the
IF frequency (from a white noise source at its input and its
own IF noise), to the overall noise figure measurement is
practically eliminated by the high pass filter. Figure 1 shows
an implementation of a high pass filter network used to filter
out the incoming IF noise from the LNA. A rider board can be
built to connect the LNAOUT and the RFIN SMA connectors
of the demo-board. The 1000pF decoupling capacitors are
included in the demo-board.
LNAOUT
Background
HFA3600
LOW NOISE
LO
FILTER
BROADBAND
FILTER A
NOISE
SOURCE
HP8970A
NOISE
FIGURE
METER
HP346B
LNA
TUNED
AT THE
RF FREQ
HFA3600
FIGURE 37A. SSB NOISE FIGURE MEASUREMENT
FILTER
BROADBAND
NOISE
SOURCE
LOW NOISE
LO
HP8970A
NOISE
FIGURE
METER
HP346B
LNA
HFA3600
FIGURE 37B. DSB NOISE FIGURE MEASUREMENT
TABLE 3. DSB MEASUREMENT SET UP
(NO INPUT BANDPASS FILTER)
NF
(dB)
GAIN
(dB)
Saw, 3dB Loss
5.1
16.0
Short/No Filter
1.8
31
Π Filter, No Loss
at the RF
Frequency
3.6
19.0
IMAGE FILTER
COMMENTS
Equivalent to SSB
Measurement
Invalid Measurement
Note 3
NOTES:
2. The single side band input filter (filter A) loss is accounted for and
removed in the Noise figure and gain values.
3. The difference of a DSB to a SSB noise figure is theoretically
3dB. The expected value of 2.2dB NF for a DSB measurement
is degraded to 3.6db due to a small attenuation of the Π filter at
the image frequency.
4. The cascaded results presented in the AC Specifications Table
of the data sheet are calculated assuming the use of an ideal
image filter (no loss) and a SSB measurement.
HFA3600 Mixer Evaluation Notes
The evaluation of the HFA3600 mixer by itself is facilitated
by the demo-board design which provides access to the 3
ports by SMA connectors. As discussed before, RF to IF
feedthrough and LO to RF/IF ports moderate isolation can
cause errors during noise measurements.
The inherent RF to IF feedthrough of the single balanced
mixer mandates that noise measurements be single side
band only (with an appropriate band pass filter at the RF
frequency of interest). Because of this lack of isolation, the
incoming energy located at the IF passband from a
15
broadband noise source for example, will feedthrough and
cause significant noise figure measurement errors.
As noise measurement equipment often makes use of
broadband noise sources with energy covering a wide
spectrum, SSB measurements are made using a band
pass filter in front of the RF port. The role of the band pass
filter is to prevent the image and IF noise energy from being
fed to the mixer.
However, band pass filters exhibit poor return losses at
frequencies outside their passbands. Because a moderate
amount of power from a local oscillator is transferred back to
the RF port in many active mixers, and this returned LO
signal is outside the passband of the SSB filter being used,
the signal will get reflected back again to the RF port due to
impedance mismatch between the filter and the RF port.
This impedance mismatch occurs at the LO frequency and
these multiple signal reflections can affect gain and noise
performance of the mixer. This situation, although not a
problem for the actual receiver design, can become a source
of error during mixer noise measurements.
To minimize the problem, the simplest method is to provide a
short connection (well below λ/4 of the LO frequency)
between the filter and the RF port. In case a coaxial cable
connection is required, it maybe necessary to provide a
length of cable which assures minimum degradation to the
noise figure reading. Long cables above 3 feet can provide
the required standing wave dissipation for measurements in
the 800MHz to 1GHz range. Note that long cable losses
must be taken into account for the purpose of noise figure
measurements. Adjustable line stretchers or isolators at the
RF input port could also be used to optimize noise figure
readings as an option for the mixer evaluation.
And finally, the recommendation of filtering the local
oscillator signal before applying it to the LO port is important
for accuracy of noise measurements when evaluating the
mixer by itself, due to the typical LO to IF feedthrough in
single balanced mixers.
HFA3600 LNA Evaluation Notes
The evaluation of the LNA is straightforward. SMA
connectors are provided in the demo-board. There are no
recommendations for evaluating the LNA block other than
using typical RF amplifier test techniques.
Final Note
The cascaded evaluation of the HFA3600 LNA and mixer
blocks including an image rejection or high pass filter is the
best method to obtain accurate results. The gain and noise
performance contribution of the LNA and filter to the
cascaded results surpass considerably the performance
contribution of the mixer. The data collected by cascading
the blocks together reflects the performance at the system
level which includes the filter of choice for a required design.
HFA3600
Small Outline Plastic Packages (SOIC)
M14.15 (JEDEC MS-012-AB ISSUE C)
N
INDEX
AREA
0.25(0.010) M
H
14 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE
B M
E
INCHES
-B-
1
2
3
L
SEATING PLANE
-A-
h x 45o
A
D
-C-
µα
e
A1
B
0.25(0.010) M
C A M
SYMBOL
MIN
MAX
MIN
MAX
NOTES
A
0.0532
0.0688
1.35
1.75
-
A1
0.0040
0.0098
0.10
0.25
-
B
0.013
0.020
0.33
0.51
9
C
0.0075
0.0098
0.19
0.25
-
D
0.3367
0.3444
8.55
8.75
3
E
0.1497
0.1574
3.80
4.00
4
e
C
0.10(0.004)
B S
0.050 BSC
1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of
Publication Number 95.
1.27 BSC
-
H
0.2284
0.2440
5.80
6.20
-
h
0.0099
0.0196
0.25
0.50
5
L
0.016
0.050
0.40
1.27
6
N
NOTES:
MILLIMETERS
α
14
0o
14
8o
0o
7
8o
Rev. 0 12/93
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate burrs.
Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006
inch) per side.
4. Dimension “E” does not include interlead flash or protrusions. Interlead
flash and protrusions shall not exceed 0.25mm (0.010 inch) per side.
5. The chamfer on the body is optional. If it is not present, a visual index
feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
16
Similar pages