AN206 - Infineon

:
BGB741L7ESD and BGS12AL7
LNA and RF switch for mobile TV
A pplications
A pplication Note AN206
Revision: Rev. 1.0
2010-07-30
RF and Protection Devices
Edition 2010-07-30
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2010 Infineon Technologies AG
All Rights Reserved.
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BGB741L7ESD and BGS12AL7
for mobile TV Applications
Application Note AN206
Revision History: 2010-07-30
Previous Revision:
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Subjects (major changes since last revision)
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Last Trademarks Update 2009-10-19
Application Note AN206, Rev. 1.0
3 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Product Description
Table of Content
1
Product Description...........................................................................................................................5
2
Application Information.....................................................................................................................7
3
BGB741L7ESD and BGS12AL7-4 Application Schematics ...........................................................8
4
Measurement Results Summary.....................................................................................................11
5
Measured Graphs.............................................................................................................................12
6
Evaluation Board and layout Information......................................................................................18
Appendix 1: ESD protection circuit for system level ESD robustness ......................................20
Author................................................................................................................................................23
List of Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
Figure 25
Block Diagram of the BGB741L7ESD..................................................................................................5
Functional and Pinout Diagram of BGS12AL7-4 .................................................................................6
Block diagram of of TV and FM reception in mobile phone application...............................................7
Block Diagram of an application for analog and digital TV ..................................................................8
Schematics of the BGB741L7ESD application. ...................................................................................8
Schematic of the BGS12AL7-4 application..........................................................................................9
Test Set-up for LNA/Switch configuration ..........................................................................................10
Insertion Power Gain on RF1 and RF2 Outputs. ...............................................................................12
Noise figure ........................................................................................................................................12
Input Matching....................................................................................................................................13
Output Matching .................................................................................................................................13
Z Parameters of In- and Output Matching..........................................................................................14
Reverse Isolation of the BGB741L7ESD ...........................................................................................14
Isolation of RF1 and RF2 ...................................................................................................................15
Stability shown in k Factor .................................................................................................................15
Stability shown in MU Factor..............................................................................................................16
IM 3 Measurement .............................................................................................................................16
1dB Compression Characteristic........................................................................................................17
Photo of Evaluation Board .................................................................................................................18
PCB Layer Information.......................................................................................................................18
Photo of BGS12A eva board..............................................................................................................19
PCB Structure of the Eva Board ........................................................................................................19
ESD test pulse according to system level specification IEC61000-4-2 – Contact Discharge 15kV ..20
Smart 2-step ESD protection approach based on external and internal ESD protection structure ...21
Standard ESD protection topology with optional ESD resistor, blocking capacitor and a serial
inductor...............................................................................................................................................22
List of Tables
Table 1
Table 2
Table 3
Table 4
Pin definition and function ....................................................................................................................6
Pin definition and function ....................................................................................................................7
Bill-of-Materials.....................................................................................................................................9
Summary of Measurement Results....................................................................................................11
Application Note AN206, Rev. 1.0
4 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Product Description
1
Product Description
1.1
BGB741L7ESD: Broadband MMIC Low Noise Amplfier
The MMIC LNA BGB741L7ESD from Infineon Technologies is a high performance
broadband amplifier for wireless solutions.
Built up with Silicon Germanium: Carbon (SiGe: C) technology, the BGB741L7ESD offers an
excellent noise figure over broad frequency band. The biasing and stabilization circuits built
inside the BGB741L7ESD reduce the number of external parts down to 6 and make the
BGB741L7ESD interesting for compact and high performance LNA designs.
The component can be used from 1.8V until 4.0V and from 5mA to 30mA.
Furthermore, this device includes an integrated ESD protection circuit on chip which protects
the device upto 4.0kV at the input pin and 2.5kV at the output pin (according to Human Body
Model). A CMOS-technology compliant power-on/off function is also integrated in the device.
The first figure presents the block diagram of the BGB741L7ESD. The device is packaged in
TSLP-7-1 format and the pinning information is summarized in the table 1.
Figure 1
Block Diagram of the BGB741L7ESD.
Application Note AN206, Rev. 1.0
5 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Product Description
Table 1
Pin N°
1
2
3
4
5
6
7
Pin definition and function
Name
Vcc
Vbias
RFin
RFout
Vctrl
Adj
GND
Function
Voltage supply
Output of biasing circuitry to the transistor base
RF input of the BGB741L7ESD LNA
RF output of the LNA
Power off/on mode Function
Current adjustment
Ground of the BGB741L7ESD
For more details please refer to the datasheet of the BGB741L7ESD available in the Infineon
internet pages
1.2
SPDT RF Switch BGS12AL7-4
The BGS12AL7-4 General Purpose RF MOS switch is designed to cover a broad range of
applications from 30 MHz to 3 GHz. The symmetric design of its single pole double throw
configuration, as shown in Figure 2 offers high design flexibility. This single supply chip
integrates on-chip CMOS logic driven by a simple, single-pin CMOS or TTL compatible
control input signal. The 0.1 dB compression point exceeds the switch’s maximum input
power level of 21 dBm, resulting in linear performance at all signal levels. The RF switch has
a very low insertion loss of 0.4 dB in the 1 GHz and 0.5 dB in the 2 GHz range.
.
Figure 2
Functional and Pinout Diagram of BGS12AL7-4
In the table 2 the the pin names, corresponding with the pinout in figure 2 are described.
Application Note AN206, Rev. 1.0
6 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Application Information
Table 2
Pin N°
1
2
3
4
5
6
7
Pin definition and function
Name
RF2
GND
RF1
Vdd
RFin
Ctrl
GND
Function
RF Port 2 Out
Ground
RF Port 1 Out
Supply Voltage
RF Port In
Control Pin
Ground
For more details please refer to the datasheet of the BGS12AL7-4 available in the Infineon
internet pages
2
Application Information
This application note presents the BGB741L7ESD as LNA combined with the RF switch
BGS12AL7-4 for mobile TV in the Frequency range 30 to 850 MHz. One typical application is
the combined reception of TV and FM with one antenna and two separated receiver ICs.
Figure 3
Block diagram of of TV and FM reception in mobile phone application.
Another application could be the reception of separated RX paths of anlog and digital TV.
Application Note AN206, Rev. 1.0
7 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
BGB741L7ESD and BGS12AL7-4 Application Schematics
Figure 4
Block Diagram of an application for analog and digital TV
Both applications use an antenna with close to 50 Ohm impedance and the receiver also
have 50 Ohm inputs.
3
BGB741L7ESD and BGS12AL7-4 Application Schematics
3.1
Evaluation boards BGB741L7
Figure 5
Schematics of the BGB741L7ESD application.
Application Note AN206, Rev. 1.0
8 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
BGB741L7ESD and BGS12AL7-4 Application Schematics
Table 3
Bill-of-Materials
Symbol
Value
Unit
Size
C1
C2
C3
C4
L1
R1
330
10
10
330
220
110
pF
nF
nF
pF
nH
Ω
0402
0402
0402
0402
0402
0402
N1
BGB741L7
3.2
TSLP-7-1
Manufacturer
Various
Various
Various
Various
Murata LQG15A
Various
Infineon
Technologies
Comment
DC block/Input matching
RF grounding
RF grounding
DC block/Output matching
DC feed/ Input matching
Output matching/ Stability
SiGe:C MMIC LNA
Evaluation board BGS12AL7-4
Application schematic of the SPDT switch offered by Infineon is shown below. It is a one chip
solution integrating RF switch and the control logic. The switch can be connected to the
respective RF and DC ports in an application directly without the need for any external
components.The device also integrates ESD protection devices which protect it against ESD
events up to 1 kV (Human Body Model; IEC61340-3-1) on all ports
Figure 6
Schematic of the BGS12AL7-4 application.
Application Note AN206, Rev. 1.0
9 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
BGB741L7ESD and BGS12AL7-4 Application Schematics
3.3
Test setup for combination LNA and Switch
Figure 7
Test Set-up for LNA/Switch configuration
In our test set-up we connect an evaluation board of the BGB741L7 with an eva board of the
BGS12AL7-4 and test the combination in a 50 Ohm test environment.
Application Note AN206, Rev. 1.0
10 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measurement Results Summary
4
Measurement Results Summary
In table 4 a summery of the measured results is shown.Vcc, Vctrl= 2.8V, I=5.4mA
Table 4
Summary of Measurement Results
Parameter
Symbol
Value
Frequency Range
Freq
DC Voltage
Vcc
2.8
V
DC Current
Icc
5.4
mA
Gain
G
50
15.1
450
15.0
Unit
850
14.7
Note/Test Condition
MHz
dB
Noise Figure
NF
2.2
1.2
1.5
dB
Input Return Loss
RLin
-7.6
-10
-8.2
dB
Output Return Loss
RLout
-9.2
-26
-22
dB
Reverse Isolation
|IRev|
24
27.8
25.5
dB
Power @ port1= -30
dBm
Including SMA
connectors
and PCB losses of
0.1dB
Power @ port2 = -10
dBm
Power @ Input = -30
dBm
Input IP3
IIP3
-3
dBm
Measured @
f1=840MHz
∆f =1 MHz
Output IP3
OIP3
11.9
dBm
Stability
k
>1.4
--
Application Note AN206, Rev. 1.0
11 / 24
Stability measured up to
10GHz
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
5
Measured Graphs
Insertion Power Gain
20
50 MHz
15.05 dB
850 MHz
14.71 dB
15
10
DB(|S(2,1)|)
RF_1
5
DB(|S(2,1)|)
RF_2
0
0
Figure 8
100
200
300
400
500
600
Frequency (MHz)
700
800
900
1000
Insertion Power Gain on RF1 and RF2 Outputs.
Noise figure
5
NF_rf1
NF_RF2
NF(dB)
4
50 MHz
2.39 dB
3
850 MHz
1.53 dB
2
1
0
Figure 9
100
200
300
400
500
600
Frequency (MHz)
700
800
900
1000
Noise figure
Application Note AN206, Rev. 1.0
12 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
Input Matching
0
50 MHz
-7.493 dB
-5
850 MHz
-8.274 dB
-10
-15
DB(|S(1,1)|)
RF_1
-20
DB(|S(1,1)|)
RF_2
-25
0
Figure 10
100
200
300
400
500
600
Frequency (MHz)
700
800
900
1000
Input Matching
Output Matching
0
DB(|S(2,2)|)
RF_2
-5
50 MHz
-9.137 dB
DB(|S(2,2)|)
RF_1
-10
-15
850 MHz
-21.64 dB
-20
-25
-30
0
Figure 11
100
200
300
400
500
600
Frequency (MHz)
700
800
900
1000
Output Matching
Application Note AN206, Rev. 1.0
13 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
Z Parameters Input output matching
2.
0
0.
6
0.8
1.0
Swp Max
1040MHz
0.
4
3.
0
4.
5. 0
10.0
10.0
5.0
4.0
3.0
50 MHz
r 0.980815
x 0.912439
2.0
1.0
0.8
0.4
0.2
0.2
0
0.6
850 MHz
r 1.07149
x -0.156478
0
50 MHz
r 0.981159
x -0.738393
-10.0
2
0
.0
.0
.4
-0
.0
-2
Swp Min
40MHz
-1.0
-0.8
Z11_RF2
Figure 12
850 MHz
r 0.718848
x -0.650785
6
-0
.
Z22_RF1
-3
Z22_RF2
-4
Z11_RF1
-5 .
- 0.
Z Parameters of In- and Output Matching
Reverse Isolation
50
45
40
35
50 MHz
24.73
30
850 MHz
23.43
25
20
15
RF1
10
RF2
5
0
0
Figure 13
100
200
300
400
500
600
Frequency (MHz)
700
800
900
1000
Reverse Isolation of the BGB741L7ESD
Application Note AN206, Rev. 1.0
14 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
Isolation_RF1_RF2
20
10
0
-10
-20
DB(|S(2,1)|)
RF_1
-30
DB(|S(2,1)|)
[email protected]=on
DB(|S(2,1)|)
RF_2
DB(|S(2,1)|)
[email protected]=on
-40
0
Figure 14
200
400
600
Frequency (MHz)
800
1000
Isolation of RF1 and RF2
Stability K Factor
10
9
8
7
6
5
4
3
2
K()
RF_1
1
K()
RF_2
0
0
Figure 15
2000
4000
6000
Frequency (MHz)
8000
10000
Stability shown in k Factor
Application Note AN206, Rev. 1.0
15 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
Stability Mu factor
5
4
3
2
1
MU2()
RF_1
MU1()
RF_2
MU1()
RF_1
MU2()
RF_2
0
0
2000
Figure 16
Stability shown in MU Factor
Figure 17
IM 3 Measurement
4000
6000
Frequency (MHz)
8000
10000
Input Stimulus for Amplifier Two-Tone Test.
Application Note AN206, Rev. 1.0
16 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Measured Graphs
f1 = 839.5 MHz, f2 = 840.5 MHz, -30 dBm each tone.
Input IP3 = -30 + (53.8 / 2) = -3.1dBm
Output IP3 = -3.1+ 15 = + 11.9 dBm
Compression point at 1dB
20
-27 dBm
14.9 dB
Gain(dB)
15
-8.168 dBm
13.91 dB
10
5
0
-27
Figure 18
-22
-17
-12
Pin (dBm)
-7
-2
0
1dB Compression Characteristic
Application Note AN206, Rev. 1.0
17 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Evaluation Board and layout Information
6
Evaluation Board and layout Information
6.1
BGB741L7 Evaluation Board
Figure 19
Photo of Evaluation Board
Figure 20
PCB Layer Information
Application Note AN206, Rev. 1.0
18 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Evaluation Board and layout Information
6.2
BGS12A Eva Board
Figure 21
Photo of BGS12A eva board
This section deals with some tips and recommendations for the PCB design. Standard FR4
can be used as the PCB substrate material, but in order to keep the losses as low as
possible, Rogers 4003 is used for the application boards provided by Infineon for switch
evaluation. In addition, to attain mechanical strength, a layer of FR4 can be used in a
multilayer configuration as shown in Figure 13. Signal grounding is a prime concern for RF
circuits and thus it is recommended to have via holes under the chip for an optimum RF
grounding. The vias under the chip also act as a good heat sink. For the given PCB structure,
the microstrip line width is 0.45 mm, with a spacing of 1.2 mm to the coplanar ground plane.
Copper Top
Copper Middle
Rogers 4003, 0.2mm
FR4, 0.8 mm
PCB_CS.vsd
Copper Bottom
Figure 22
Cu 35µm
PCB Structure of the Eva Board
Application Note AN206, Rev. 1.0
19 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Appendix 1: ESD protection circuit for system level ESD robustness
Appendix 1: ESD protection circuit for system level ESD robustness
Introduction
With the advancement in miniaturization of semiconductor structures, ESD handling
capability of the devices is becoming a concern. Increasing ESD handling capability of the I/O
ports costs additional chip size and affects the I/O capacitance significantly. This is very
important for high frequency devices, especially when high linearity is required. Therefore,
tailored and cost effective ESD protection devices can be used to build up an ESD protection
circuit. To handle ESD events during assembly, devices normally have on-chip ESD
protection according to the device level standards e.g. “Human Body Model” JEDEC 22-A115. To fulfill the much more stringent system level ESD requirements according to
IEC61000-4-2 as shown in Figure 23, the external ESD protection circuit has to handle the
majority of the ESD strike. The best external ESD protection is achieved using a TVS diode
assisted by additional passive components.
ESD_current, A
60
m6
Reference Pulse
15kV contact discharge
according IEC61000-4-2
40
m6
time=1.507nsec
ESD_current=57.68 A
m7
time=30.01nsec
ESD_current=29.43 A
m7
m8
20
m8
time=60.01nsec
ESD_current=15.18 A
0
0
20
40
60
80
100
120
time, nsec
Figure 23
140
160
180
200
ESD_Pulse.vsd
ESD test pulse according to system level specification IEC61000-4-2 – Contact Discharge
15kV
Some examples of RF applications addressed by the Infineon ESD protection proposal are
given below:
•
•
•
•
•
•
•
FM Radio (76 MHz -110 MHz)
Portable TV (50 MHz – 850 MHz)
WLAN 802.11b/g/n (2.4 GHz, Tx ~ +20 dBm)
Bluetooth (2.4 GHz, Tx ~ +20 dBm)
Automatic Meter Reading, AMR (900 MHz, TX ~ +20 dBm)
Remote Keyless Entry, RKE (315 MHz - 434 MHz - 868 MHz - 915 MHz, Tx~13 dBm)
GPS (1575 MHz, Rx only but can be affected by RF interferer)
For an ESD protection device tailored for medium power RF signals (=< +20 dBm), following
requirements are essential:
Application Note AN206, Rev. 1.0
20 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Appendix 1: ESD protection circuit for system level ESD robustness
1. RF requirements
a) Bidirectional characteristic to handle DC free signals without clipping / signal distortion
b) A highly symmetrical behavior of the ESD device for positive and negative voltage
swings is mandatory to keep the power level of even Harmonics low
c) Breakdown voltage of 5 V-10V, to avoid signal distortion at high RF voltage swing
applied at the TVS diode, located close to the antenna
d) High linearity
e) Low leakage current and stable diode capacitance vs. RF voltage swing
f) Ultra low diode capacitance is mandatory
2. ESD requirements
a) Lowest dynamic resistance Rdyn to offer best protection for the RFIC; Rdyn is
characterized by Transmission Line Pulse (TLP) measurement
b) Very fast switch-on time (<<1nsec) to ground the initial peak of an ESD strike according
to IEC61000-4-2
c) No performance degradation over a large number of ESD zaps (>1000)
Two-step ESD Protection approach
General structure for a 2-step ESD approach according to Figure 24 enables to split the
entire ESD current between the internal and external ESD protection device. The external
device is much more robust and handles the majority of the ESD current. To avoid any
impact on the RF behavior of the system and to minimize non linearity effects, the TVS diode
should possess an ultra low device capacitance.
Therefore the bi-directional (symmetrical) Infineon TVS Diode ESD0P2RF is well suited,
which provides a diode capacitance as low as 0.2 pF and a Rdyn of only 1 Ohm. ESD
robustness can be improved one step more by adding a small serial resistor between the
external TVS diode and the RF amplifier input. A resistor of ~2.2 Ohm is a good compromise
between additional ESD performance and insertion loss. The TVS diode ESD0P2RF in
combination with the 2.2 Ohm ESD resistor would incur less than 0.23dB insertion loss up to
3 GHz.
Figure 24
Smart 2-step ESD protection approach based on external and internal ESD
protection structure
Application Note AN206, Rev. 1.0
21 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Appendix 1: ESD protection circuit for system level ESD robustness
For further ESD improvement it is highly recommend to add a serial capacitor (C1). The
capacitor cuts off most of the high energy created by the ESD strike. For better ESD
robustness, C1 should be as small as possible, but has to match to the intended application
frequency as well. For a broadband ESD protection (80MHz…3GHz) C1 should be about
100pF…150pF. Optional matching can be implemented with a serial inductor L1 for a
dedicated frequency. In combination with L1, C1 can be reduced significantly which improves
the ESD performance.
Figure 25
Standard ESD protection topology with optional ESD resistor, blocking capacitor and a
serial inductor
Application Note AN206, Rev. 1.0
22 / 24
2010-07-30
BGB741L7ESD and BGS12AL7
for mobile TV Applications
Author
Author
Ralph Kuhn, Senior Staff Application Engineer of Business Line “RF and Protection Devices”
Application Note AN206, Rev. 1.0
23 / 24
2010-07-30
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
AN206