AN220 - Infineon

BF P7 4 0 F ES D
BF P7 4 0 F ES D E SD - Ha r d e n e d Si Ge : C
Ul tr a L o w No i s e R F Tra n s i s to r wi t h
2 k V ES D Ra ti n g i n 5 – 6 G Hz L NA
Ap p l i c a ti o n . 1 7 d B G a i n , 1 .4 d B No i s e
Fi g u r e & < 1 0 0 n s T u rn - O n / T u rn - O ff
Ti m e
Fo r 8 0 2 . 1 1 a & 8 0 2 . 1 1 n “ MI M O”
W i re l e s s L A N Ap p l i c a ti o n s
Ap p l i c a ti o n N o te A N 2 2 0
Revision: Rev. 1.0
2010-07-02
RF a n d P r o te c ti o n D e vi c e s
Edition 2010-07-02
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2010 Infineon Technologies AG
All Rights Reserved.
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BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Application Note AN220
Revision History: 2010-07-02
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Subjects (major changes since last revision)
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Last Trademarks Update 2009-10-19
Application Note AN220, Rev. 1.0
3 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
List of Content, Figures and Tables
Table of Content
1
Overview ............................................................................................................................................. 6
2
Typical Measurement Results........................................................................................................... 6
3
Schematic Diagram ............................................................................................................................ 7
4
Bill of Material ..................................................................................................................................... 8
5
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.9.1
5.9.2
Measured Graphs ............................................................................................................................... 9
Noise Figure ......................................................................................................................................... 9
1 dB Compression Point .................................................................................................................... 11
Gain .................................................................................................................................................... 12
Input Return Loss ............................................................................................................................... 13
Output Return Loss ............................................................................................................................ 15
Reverse Isolation................................................................................................................................ 17
Amplifier Stability ................................................................................................................................ 19
Third Order Intercept Point ................................................................................................................. 20
Turn-On / Turn-Off Time .................................................................................................................... 21
Turn On Time ..................................................................................................................................... 22
Turn Off Time ..................................................................................................................................... 22
6
Details of PC Board Construction .................................................................................................. 24
7
TSFP-4 Package Outline and Footprint ......................................................................................... 26
8
ESD Protection ................................................................................................................................. 27
Authors
28
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
Schematic Diagram .............................................................................................................................. 7
Noise Figure Plot, from Rohde and Schwarz FSEK3 + FSEM30 ........................................................ 9
Input 1 dB Compression Point ........................................................................................................... 11
Forward Gain...................................................................................................................................... 12
Input Return Loss in dB ...................................................................................................................... 13
Input Return Loss, Smith Chart .......................................................................................................... 14
Output Return Loss in dB ................................................................................................................... 15
Output Return Loss, Smith Chart ....................................................................................................... 16
Reverse Isolation................................................................................................................................ 17
Reverse Isolation, Amplifier DC Power turned off.............................................................................. 18
Definition of Stability Factor µ1 .......................................................................................................... 19
Stability Factor.................................................................................................................................... 19
Carrier and Intermodulation Products at LNA’s Output...................................................................... 20
Test setup for Turn-On / Turn-Off measurements ............................................................................. 21
Turn On Time ..................................................................................................................................... 22
Turn Off time ...................................................................................................................................... 23
View of entire PC Board, Top / Component Side............................................................................... 24
Close-In View of LNA Section ............................................................................................................ 24
Backside of PCB ................................................................................................................................ 25
PCB Layer Information ....................................................................................................................... 25
TSFP-4 package outline ..................................................................................................................... 26
Recommended Soldering Footprint ................................................................................................... 26
Application Note AN220, Rev. 1.0
4 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
List of Content, Figures and Tables
List of Tables
Table 1
Table 2
Table 3
Electrical Characteristics (at room temperature).................................................................................. 6
Bill-of-Materials..................................................................................................................................... 8
Noise Figure, Tabular Data ................................................................................................................ 10
Application Note AN220, Rev. 1.0
5 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Overview
1
Overview
The BFP740FESD is a high gain, ultra low noise Silicon-Germanium-Carbon (SiGe:C) HBT device suitable for a
wide range of Low Noise Amplifier (LNA) applications. The BFP740FESD has internal ESD-protection
structures giving an ESD-survival rating of 2000 Volts per the Human Body Model (HBM), for ESD strikes of
either polarity applied across any pair of terminals (Base, Emitter, Collector).
The circuit shown in this document is targeted for 802.11a & 802.11n “MIMO” applications in the Wireless Local
Area Network (WLAN) market, particularly for Access Points (AP’s) which require external LNA’s to fulfill highsensitivity / long range requirements. LNA’s for this application must be able to switch on / off within about 1
microsecond (1000 nanoseconds). The charge storage (capacitance) used in the circuit is minimized to reduce
turn-on / turn-off times. Trade-off for reduced capacitance values is a reduction in Third Order Intercept (IP3)
performance. Amplifier is Unconditionally Stable (µ1 > 1.0) from 10 MHz – 12 GHz.
External parts count (not including BFP740F transistor) = 12; 6 capacitors, 3 resistors, and 3 chip inductors. All
passives are ‘0402’ case size. BFP740FESD transistor package is RoHS – compliant and measures 1.4 x 1.2 x
0.55mm.
2
Typical Measurement Results
Table 1
Electrical Characteristics (at room temperature)
Parameter
Symbol
Value
Unit
Frequency
Freq
5.470
GHz
DC Voltage
Vcc
3.0
V
DC Current
Icc
14.8
mA
Gain
G
17.1
dB
Network analyzer source power = -25 dBm
Noise Figure
NF
1.4
dB
Does not extract PCB loss. If PCB loss at input
were extracted, NF would be ~0.2 dB lower
Input Return Loss
RLin
11.4
dB
Network analyzer source power = -25 dBm
Output Return Loss
RLout
10.3
dB
Network analyzer source power = -25 dBm
Reverse Isolation
IRev
24.9
dB
Network analyzer source power = -25 dBm
When DC Power to LNA is OFF: 14.2dB
Input P1dB
IP1dB
-8.7
dBm
Output P1dB
OP1dB
+7.4
dBm
Input IP3
IIP3
+0.8
dBm
Input power -23dBm / tone, ∆f = 1MHz
Output IP3
OIP3
+17.9
dBm
Input power -23dBm / tone, ∆f = 1MHz
Application Note AN220, Rev. 1.0
6 / 29
Comment/Test Condition
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Schematic Diagram
3
Schematic Diagram
Figure 1
Schematic Diagram
Application Note AN220, Rev. 1.0
7 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Bill of Material
4
Bill of Material
Table 2
Bill-of-Materials
Symbol
Value
Unit
Size
Manufacturer
Comment
C1
0.4
pF
0402
Input matching
C2
1.5
pF
0402
Murata
GRM1555C1HR30BZ01D
or equivalent
various
Input DC block, input matching
C3
1.5
pF
0402
various
RF decoupling / blocking cap
C4
33
pF
0402
various
RF decoupling / blocking cap
C5
1.2
pF
0402
various
RF decoupling / blocking cap
C6
0.3
pF
0402
L1
6.8
nH
0402
L2
1.3
nH
0402
Murata LQP15M series
L3
1.5
nH
0402
Murata LQP15M series
R1
22
Ω
0402
various
RF Choke at LNA output, for DC bias
to collector. Also influences matching
and stability.
Output matching; also influences
input match.
For RF stability improvement
R2
30
kΩ
0402
various
DC biasing (base).
R3
39
Ω
0402
various
DC biasing (provides DC negative
feedback to stabilize DC operating
point over temperature variation,
transistor hFE variation, etc.)
TSFP-4
Infineon Technologies
LNA active device
Q1
BFP740FESD
Murata
Output DC block and output
GRM1555C1HR30BZ01D
matching. Also influences input
or equivalent
match.
Murata LQP15M series
RF Choke at LNA input (for DC bias
to base).
J1, J2
RF Edge Mount SMA Female
Connector,
142-0701-841
Emerson / Johnson
Input / Output RF connector
J3
MTA-100 Series 5 pin connector
640456-5
PC Board, Part # 740F-080919
Rev A
Tyco (AMP)
5 Pin DC connector header
Infineon Technologies
Printed Circuit Board
---
Application Note AN220, Rev. 1.0
8 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5
Measured Graphs
The reference plane of all data displayed here are the input and output SMA connectors of the evaluation board.
This means all PCB losses and SMA connector losses are included.
5.1
Noise Figure
Rohde & Schwarz
25 Jun 2010
Noise and Gain Measurement
EUT Name:
Manufacturer:
Operating Conditions:
Operator Name:
Test Specification:
Comment:
BFP740FESD 5 - 6 GHz LNA, Fast Switching / Fast Turn ON Turn OFF time
Infineon Technologies
Vcc = 3.0 V, Vce = 2.1V, I = 14.2mA
Gerard Wevers
WLAN 802.11n
PCB = 740FESD-100503 Rev A
22 June 2010
Analyzer
RF Att:
Ref Lvl:
0.00 dB
-46.00 dBm
RBW :
VBW :
1 MHz
100 Hz
Range: 30.00 dB
Ref Lvl auto: ON
Measurement
2nd stage corr: ON
Mode: Direct
ENR: 346A173.ENR
Noise Figure /dB
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
4800 MHz
Figure 2
120 MHz / DIV
6000 MHz
Noise Figure Plot, from Rohde and Schwarz FSEK3 + FSEM30
Application Note AN220, Rev. 1.0
9 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
Table 3
Frequency / MHz
1
1
Noise Figure, Tabular Data
NF / dB
Noise Temperature / K
4800
1.41
111.1
4850
1.41
111.5
4900
1.4
110.1
4950
1.4
109.9
5000
1.38
108.6
5050
1.39
109.7
5100
1.37
107.8
5150
1.38
108.9
5200
1.38
108.6
5250
1.4
110
5300
1.37
107.3
5350
1.37
107.3
5400
1.37
108
5450
1.39
109.1
5500
1.37
107.6
5550
1.39
109.7
5600
1.43
113.4
5650
1.36
106.5
5700
1.42
111.7
5750
1.39
109.3
5800
1.41
111.5
5850
1.43
113.5
5900
1.42
112.5
5950
1.44
114.4
6000
1.45
114.7
Taken with Rohde & Schwarz FSEM30 + FSEK3; System Preamplifier: MITEQ 4-8 GHz LNA
Application Note AN220, Rev. 1.0
10 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.2
1 dB Compression Point
Gain Compression at 5470 MHz, VCC = +3.0 V, I = 14.2mA, VCE = 2.1V, T = 25°C:
Rohde & Schwarz ZVB20 Vector Network Analyzer is set up to sweep input power to LNA at a fixed frequency
of 5470 MHz. X-axis of VNA screen-shot below shows input power to LNA being swept from –30 to –5 dBm.
ZVB20 output power over sweep range is calibrated at end of test cable (reference plane at input SMA
connector to Amplifier Under Test) with Rohde & Schwarz NRP-Z21 power sensor.
Input 1 dB compression point = - 8.7 dBm
Output 1dB compression point = - 8.7 dBm + (Gain – 1dB) = -8.7 dBm + 16.1 dB = +7.4 dBm
Trc1 S21 dB Mag 0.5 dB / Ref 16 dB
Cal int PCal Offs
1
M 1 -24.56 dBm
• M 2 -8.70 dBm
S21
17.089 dB
16.080 dB
17.5
M1
17.0
16.5
M2
16.0
15.5
15.0
14.5
14.0
13.5
Ch1
Start -30 dBm
Freq 5.47 GHz
Stop -5 dBm
6/23/2010, 6:40 AM
Figure 3
Input 1 dB Compression Point
Application Note AN220, Rev. 1.0
11 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.3
Gain
Input / Output Matching Circuits of LNA reduce gain in 2.4 – 2.5 GHz band
Trc1 S21 dB Mag 10 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S21
30
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
17.100
17.085
16.655
4.4037
dB
dB
dB
dB
M 1M 2M 3
20
10
M4
0
-10
-20
-30
-40
-50
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:14 AM
Figure 4
Forward Gain
Application Note AN220, Rev. 1.0
12 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.4
Input Return Loss
Trc1 S11 dB Mag 3 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S11
12
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
-9.4544
-11.366
-9.4706
-2.5552
dB
dB
dB
dB
9
6
3
0
M4
-3
-6
M1 M3
-9
M2
-12
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:13 AM
Figure 5
Input Return Loss in dB
Application Note AN220, Rev. 1.0
13 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S11 Smith
Ref 1 U
Cal Offs
1
1
S11
M 1 5.150000 GHz
99.954
j7.7221
238.64
2
M 2 5.470000 GHz 69.548
-j26.760
1.087
M 3 5.825000 GHz 32.483
-j22.831
5
1.197
• M 4 2.483500 GHz 7.3646
-j4.2856
M1
14.954
0.5
0
0.2
0.5
1
M4
2
5
Ω
Ω
pH
Ω
Ω
pF
Ω
Ω
pF
Ω
Ω
pF
M2
M3
-5
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:10 AM
Figure 6
Input Return Loss, Smith Chart
Application Note AN220, Rev. 1.0
14 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.5
Output Return Loss
Trc1
S22 dB Mag 5 dB / Ref 0 dB
Mem2[Trc1] S11 dB Mag 5 dB / Ref 0 dB
Cal Offs
Invisible
1
M1
M2
M3
•M 4
S22
10
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
-9.2165
-10.323
-14.328
-0.6761
dB
dB
dB
dB
5
M4
0
-5
M1
M2
-10
M3
-15
-20
-25
-30
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/14/2008, 9:42 AM
Figure 7
Output Return Loss in dB
Application Note AN220, Rev. 1.0
15 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S22 Smith
Ref 1 U
Cal Offs
1
1
S22
M 1 5.150000 GHz
M4
0.5
M3
0
0.2
0.5
1
M2
35.800
-j20.169
1.532
2
M 2 5.470000 GHz 32.573
-j5.8874
4.942
M 3 5.825000 GHz 45.974
j3.3389
5
91.227
• M 4 2.483500 GHz 2.3068
j25.616
1.642
2
5
Ω
Ω
pF
Ω
Ω
pF
Ω
Ω
pH
Ω
Ω
nH
M1
-5
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:20 AM
Figure 8
Output Return Loss, Smith Chart
Application Note AN220, Rev. 1.0
16 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.6
Reverse Isolation
Trc1 S12 dB Mag 10 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S12
10
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
-25.494
-24.886
-24.640
-45.494
dB
dB
dB
dB
0
-10
-20
M 1M 2M 3
-30
-40
M4
-50
-60
-70
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:18 AM
Figure 9
Reverse Isolation
Application Note AN220, Rev. 1.0
17 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S12 dB Mag 10 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S12
10
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
-15.536
-14.212
-12.234
-34.711
dB
dB
dB
dB
0
M3
M 1M 2
-10
-20
M4
-30
-40
-50
-60
-70
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:19 AM
Figure 10
Reverse Isolation, Amplifier DC Power turned off
Application Note AN220, Rev. 1.0
18 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.7
Amplifier Stability
Rohde and Schwarz ZVB Network Analyzer calculates and plots stability factor “µ1” of the BFP740FESD
1
amplifier in real time. Stability Factor µ1 is defined as follows :
Figure 11
Definition of Stability Factor µ1
The necessary and sufficient condition for Unconditional Stability is µ1 > 1.0. In the plot, µ1 > 1.0 over 10 MHz
– 12 GHz; amplifier is Unconditionally Stable over 10 MHz – 12 GHz frequency range.
Trc1 µ1 Lin Mag 200 mU/ Ref 1.6 U
Cal Offs
1
M1
M2
M3
•M 4
µ1
2200.0
5.150000
5.470000
5.825000
2.483500
GHz
GHz
GHz
GHz
1.1979
1.3102
1.5296
1.0403
U
U
U
U
2000.0
1800.0
M3
1600.0
M2
1400.0
M1
1200.0
M4
1000.0
800.0
600.0
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
6/23/2010, 6:23 AM
Figure 12
1
Stability Factor
“Fundamentals of Vector Network Analysis”, Michael Hiebel, 4th edition 2008, pages 175 – 177, ISBN 978-3-939837-06-0
Application Note AN220, Rev. 1.0
19 / 29
2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.8
Third Order Intercept Point
In-Band Third Order Intercept (IIP3) Test.
Input Stimulus: f1=5470 MHz, f2=5471 MHz, -23 dBm each tone.
Input IP3 = -23 + (47.5 / 2) = +0.8 dBm.
Figure 13
Output IP3 = +0.8 dBm + 17.1 dB gain = +17.9 dBm.
Carrier and Intermodulation Products at LNA’s Output
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.9
Turn-On / Turn-Off Time
The amplifier is tested for turn-on / turn-off time. See diagram below. The RF signal generator runs
continuously at a power level sufficient to drive the output of the LNA to approximately 0 dBm when the LNA has
DC power ON.
Agilent
DSO6104A
Digital
Oscilloscope
+3 Volts
Ch. 1 (Trigger, edge)
1 Megaohm input Z
Amplifier
6 dB
Attenuator
Pad
Signal
Generator
f=5470 MHz
Agilent
8473B
Detector
Ch. 2 (50 ohm input Z)
! Note !
Set Ch. 2 Input Impedance to 50 ohms, not 1M ohm! 1M ohm
setting will not allow detector to discharge rapidly, and will give
erroneous results to turn-off time measurment, e.g. will indicate
excessively long turn-off times.
1. Signal Generator set such that output power of BFP740F LNA is approx. 0
dBm when LNA is powered ON
2. Channel 1 of oscilloscope monitors input power supply voltage to
Amplifier (+3.0 volts when ON, ~ 0 volts when OFF)
3. Channel 2 of oscilloscope monitors rectified RF output of Amplifier
4. To make measurement of turn-on time, turn power supply OFF, reset
o’scope, setup trigger to trigger on rising edge of Ch.1
5. To make measurement of turn-off time, turn power supply ON, reset
o’scope, setup trigger to trigger on falling edge of Ch. 1
Figure 14
Test setup for Turn-On / Turn-Off measurements
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
5.9.1
Turn On Time
Refer to oscilloscope screen-shot below. Upper trace (yellow, Channel 1) is the DC power supply turn-on step
waveform whereas the lower trace (green, Channel 2) is the rectified RF output signal of the LNA stage.
Amplifier turn-on time is aproximately 35 ns, or 0.035 ms. Main source of time delay in the LNA turn-on and
turn-off events are the R-C time constants formed by (R3 * C4), [(R2+R3) * C3], etc. Charge storage has been
minimized in this circuit so as to speed up turn on and turn off times. (Refer to Figure 1).
Figure 15
Turn On Time
5.9.2
Turn Off Time
Upper trace (Channel 1, yellow color) is the falling edge of the DC power supply voltage. Rectified RF output
signal (Channel 2, lower green trace) takes about ~ 25 ns or ~ 0.025 ms to settle out after power supply is
turned off.
Note that input impedance of digital oscilloscope which senses RF Detector Diode output is set to 50 Ω, rather
than 1 MΩ, to permit RF Detector Diode to rapidly discharge after Amplifier is turned off.
If input impedance of oscilloscope is set to 1 MΩ, the RF Detector will have to discharge through this 1 MΩ
impedance, giving excessively long results for the turn-off time measurement.
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Measured Graphs
Figure 16
Turn Off time
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Details of PC Board Construction
6
Details of PC Board Construction
Figure 17
View of entire PC Board, Top / Component Side
Figure 18
Close-In View of LNA Section
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Details of PC Board Construction
Figure 19
Backside of PCB
PC board is fabricated from standard, low-cost “FR4” glass-epoxy material. A cross-section diagram of the PC
board is given below.
PCB CROSS SECTION
0.012 inch / 0.305 mm
TOP LAYER
INTERNAL GROUND PLANE
0.028 inch / 0.711 mm ?
LAYER FOR MECHANICAL RIGIDITY OF PCB, THICKNESS HERE NOT CRITICAL AS
LONG AS TOTAL PCB THICKNESS DOES NOT EXCEED 0.045 INCH / 1.14 mm
(SPECIFICATION FOR TOTAL PCB THICKNESS: 0.040 + 0.005 / - 0.005 INCH;
1.016 + 0.127 mm / - 0.127 mm )
BOTTOM LAYER
Figure 20
PCB Layer Information
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
TSFP-4 Package Outline and Footprint
7
TSFP-4 Package Outline and Footprint
Dinensions in millimeters. Note maximum package height is 0.59 mm / 0.023 inch
Figure 21
TSFP-4 package outline
Recommended Soldering Footprint for TSFP-4 (dimensions in millimeters). Device package is to be oriented as
shown in above drawing (e.g. orient long package dimension horizontally on this footprint).
Figure 22
Recommended Soldering Footprint
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
ESD Protection
8
ESD Protection
Electrostatic discharge (ESD) plays an important role when ESD sensitive devices are connected to exposed
interfaces or antennas that can be touched by humans. This is usually applicable to low noise amplifiers (LNAs)
and therefore LNAs must be properly protected against ESD in order to avoid irreversible damage of the LNA.
For mobile applications low voltage supply and low current consumption is a major issue that requires new
technologies with smaller transistor structures. However, the smaller the transistor structure the more sensitive
the transistor is to ESD events. Therefore, RF-LNAs based on new front-end technologies have already ESD
protection elements integrated on-chip, e.g. BFP740FESD, BFP640FESD, BFP540FESD. These on-chip ESD
protection techniques are always a compromise between good ESD protection and RF performance. Integrated
RF ESD concepts hardly ever achieve an ESD protection above ±2 kV according HBM. An on-chip ESD
protection of ±1 kV HBM (component level ESD test JEDEC JESD 22-A115) is quite sufficient to protect the
chip from ESD events in the manufacturing environment where stringent measures are taken to prevent
electrostatic buildup. However in the field, exposed antennas, for example, always require higher ESD
protection levels of at least ±8kV up to ±15kV. Additional the more stringent system level test according to
IEC61000-4-2 is applied. Therefore a special ESD protection becomes mandatory to handle the majority of the
ESD current. An ESD protection based on silicon TVS diodes fits perfect to keep the residual ESD stress for the
subsequent device as small as possible.
For high frequency applications (2.4GHz and 5GHz WLAN) ESD protection diodes with ultra low line
capacitances are required. Infineon offers ultra low clamping voltage and ultra low capacitance, 0.2pF line
capacitance, ESD protection diodes in leadless packages of EIA case 0402 (TSLP-2-17) as well as 0201
(TSSLP-2-1):
ESD0P2RF-02LRH / -02LS
The Infineon TVS diode ESD0P2RF has a line capacitance of only 0.2 pF and comes in either a TSLP-2-17
package (1 mm x 0.6 mm x 0.39 mm) or a super small TSSLP-2-1 package (0.62 mm x 0.32 mm x 0.31 mm).
The ESD0P2 ESD diode is a bidirectional TVS diode with a maximum working voltage of ±5.3V. It is capable of
handling TX power levels of up to +20dBm without influencing the signal integrity, EVM and harmonic
generation. Therefore it is well suited for WLAN 2.4GHz and for a lot of 5GHz applications as well.
Application Note AN220, Rev. 1.0
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2010-07-02
BFP740FESD
BFP740FESD for 5-6GHz WLAN applications
Authors
Authors
Jerry Wevers, Senior Staff Engineer of Business Unit “RF and Protection Devices”
Dietmar Stolz, Staff Engineer of Business Unit “RF and Protection Devices”
Application Note AN220, Rev. 1.0
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2010-07-02
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
AN220